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Insulin Growth Factor-1 IGF-1
BACK
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IGF-1 & HGH Warning: You are
being deceived by dishonest "HGH suppliers
Our over the counter Rejuvenis Max
recombinant growth factor
has been clinically researched,
and is bio-identical, recombinant
growth hormone with a 10 year
track record
of life changing proof from the
industry founders as reviewed on our website.
Please believe that
what is written here
may alter the quality of your life forever; as good educational material
often does. A few minutes of reading right now
might convince you to live the rest of your life caring for your well being
by becoming more informed of... THE
FACTS !
Our scientific team of
formulators have publicly challenged the
claim of dishonest "HGH suppliers". Our formulators want to scientifically demonstrate that
the so called HGH product that these dishonest suppliers of "HGH
products" actually does not increase HGH and to refute their claim with
the scientific and clinical data and they have offered to do this for almost a decade
to show cause why their products do not increase HGH...
To date, we have yet to have a
single one of those manufacturers, their scientists, their researchers,
their doctors, their professors or anyone else
accept the challenge. We believe it is critical for your well being that you
know the truth. With the truth your choices become clear.
There are thousands of
organizations and people selling products that claim to increase growth
hormone in the human body. Most of these are so-called "proprietary"
combinations of amino acids such as ornithine and arginine, or some herbal
supplements, as well as other products labeled as "boosters", "stimulators",
"promoters", "precursors", "secretagogues", "effervescents", "homeopathic
releasers", "homeopathic/oral dilute sprays", "IGF-1 maximizers",
"supporting compounds and synergists", and other similar inferior "HGH"
type products - whether found in the form of a pill, powder, patch,
liquid, capsule or spray do not live up to their claims.
These products are NOT HGH.
These misrepresented HGH
supplements and their "suppliers" use "bait and switch" third party clinical
study results based on actual HGH injections to mislead you. The Federal
Trade Commission is attempting to stop this and this action is even making
it difficult for reputable companies to educate the public on their products.
Furthermore, we at
Anti-Aging Clinic Assoc., Inc. have tried to educate the public for
many years staying within the restrictions and guidelines placed on us
through the governing agencies through our published work, radio programs and our website, about
our products as apposed to
this and other deceptive practices. The research publication below,
issued by our scientific team of formulators to the global medical community in 1999 demonstrates the lack of
efficacy and potentially harmful side effects these deceptive practices and
products can have.
FACTS:
If it is a pill or capsule
there is
no
HGH
in that pill or capsule!.
Any HGH you swallow
is destroyed by stomach acid.
For example, unscrupulous suppliers
claim IGF (insulin like growth factor) as their marker for evidence of HGH
production. This is deceptive and potentially harmful; proven in study after
study.
Consuming sodas or candy soars IGF,
however your HGH levels plummet. Imagine a major soft drink or candy bar
maker plastering on their packaging and commercials that our product "Increases HGH!" The way
the rules are written right now, they legally can. This "loophole" is how
these unscrupulous suppliers are misleading the public; IGF is not the precursor for
measurement of HGH..
In fact, if IGF testing were no
longer used as a co-marker for measuring HGH, there would be no ability to
make these erroneous, deceptive and potentially harmful claims and the
consumer would ultimately be limited to a small number of ethical ways to
raise growth hormone levels in the bloodstream.
Again, our scientific team has publicly
challenged anyone to refute this information
for almost a decade. To date, they have yet to have a single
manufacturer, scientist, researcher, doctor, professor or anyone else, to
accept the challenge. Why? Because the truth is inarguable.
Amino Acids
at reasonable doses will increase
IGF but
will not increase HGH.
As you will see, there is
no evidence that amino acids directly increase HGH, except at very high
doses of approximately 30 grams and this is for a few weeks only. These
massive doses are not practical and can be harmful to the kidneys and liver
as well.
Studies Show
elevated IGF
without a corresponding elevation of HGH, called "ratios",
can be severely hazardous to your health,
such
as diabetes, auto
immune disorders and cancer.
However, thousands more studies
prove that
proper "ratios" of elevated IGF with
corresponding
elevated HGH
is extremely beneficial to your
health.
If you are under the age of 30 or
you do consistent resistance exercise, adapt the proper nutrition, and get
at least 7 to 8 hours of restful sleep every night, eat only the ripe fruit
picked from your orchard or only the ripe veggitalbes from your organic
garden, then
-the next best thing is
supplementing with
bio-identical
rGH Rejuvenis Max; does it replace all of those, absolutely not, does it
help; yes.
One primary way of improving HGH-- other than
consistent resistance exercise, sleep, nutrition, as well as inhibiting the anti growth
hormone substance called "somatostatin", pronounced (so-ma-toe-statin) and being under
age 30 -- is the administration of genuine growth hormone that comes with
the risk of side effects. In 1997, our scientific team of formulators
pioneered a process that does not require an injection.
This is our clinically reviewed Rejuvenis Max recombinant growth
hormone. Growth hormone administration with any product, pill or tablet or
with any other company’s purported HGH spray that we have researched simply
cannot improve your levels.
The Federal Trade Commission fortunately now understands the urgency of
these deceptive practices and is currently challenging these "suppliers" for
their evidence or demanding them to stop this gross misrepresentation.
What about
homeopathic growth hormone?
I ndeed,
many homeopathic preparations do appear to have some value,
BUT THE VERY LAW OF
HOMEOPATHY DOES NOT ALLOW FOR,
NOR PROVIDE FOR
THE PROCESSING OF AN
HGH MOLECULE.
It simply cannot possibly
work. It
violates every aspect of known science.
Additionally, the odds of just
one HGH molecule inside of
a one ounce
bottle of a homeopathic 30x
HGH preparation
are trillions to one.
Where is the
HGH?
How can a
homeopathic HGH product (30x) have 1 molecule of HGH & parts of
alcohol, water or glycerin and have any therapeutic value?
Try to fathom this:
This
homeopathic number is the equivalent of a container of alcohol, water or
glycerin more than 30 million times the size of our solar system's sun
relative to one molecule of Growth Hormone.
Furthermore, based on such
"formulations", the odds of you getting even one single molecule of Growth
Hormone in the entire bottle you purchased is
Trillions and
trillions and trillions to one.
Supposedly, this "essence" of the homeopathic growth hormone molecule,
that is
mega-trillions times smaller than an actual growth hormone molecule,
somehow has a therapeutic value is un-fathomable. This concept violates every neuron of logic
we possess or we all have missed class that particular day on quantum
theory.
No wonder homeopathic growth hormone can be sold so inexpensively, there is
no HGH benefit.
Additionally, alcohol
literally fractures and destroys the fragile growth hormone molecule. Most
homeopathic "formulations" use alcohol as their base. Therefore, even if
there was any HGH, the alcohol would render it useless. Ask them if their
"formulation" contains alcohol; you know what to do if it does, laugh and
run, unless of course you want to try and get a buzz from the alcohol.
And critically, if the HGH molecule does not have a delivery system it cannot be delivered to the cells in your body in an oral spray.
It simply must past through to mucosal directly to the blood stream. If it
goes through to the stomach acid, it is nothing. We have
yet to find a homeopathic formulation with a scientifically proven
delivery system.
In Western Medicine, to be effective on human anatomy, we look at values and
ratios, like milligram per kilogram ratios, not molecules per
galaxy.
Rejuvenis Max r GH has been clinically researched,
and is bio-identical, recombinant
growth hormone with a 10 year track
record of
life changing proof from
the industry founders.
Our Maximum
Strength Rejuvenis Max rGH is the most potent, highest quality, oral somatotropin (rGH) supplement available. Anything more powerful
and you'd be required to have a prescription.
Rejuvenis Max rGH provides the strongest, most powerful, true HGH
product that can be obtained anywhere, from any source, at any price. When
you purchase Rejuvenis Max rGH from the Anti-Aging Clinic Assoc.,
Inc., you know you've purchased the most proven, clinically researched, non
prescription rGH product in the world, almost a decade ago by telling the truth.
Again, please do not be fooled by other products labeled as "boosters",
"stimulators", "promoters", or "precursors", "secretagogues", "effervescents",
"homeopathic releasers", "homeopathic/oral dilute sprays", "IGF-1 maximizers",
"supporting compounds and synergists", and other similar inferior "HGH"
type products - whether found in the form of a pill, powder, patch,
liquid, capsule or spray - they are NOT HGH.
Use the real deal, Rejuvenis
Max rGH.
Read the following clinical
research on IGF-1
Is IGF-1 the ONLY true marker of
increased GH activity?
Introduction
Is IGF-1 always increased by
increases in GH production?
Diagnosis of growth-hormone
deficiency in adults.
Serum Levels of Insulin-like
Growth Factor-I (IGF-I) and IGF Binding Protein-3 (IGFBP-3) in Idiopathic
Tall Basketball Players.
A five day treatment with daily
subcutaneous injections of growth hormone-releasing peptide-2 causes
response attenuation and does not stimulate insulin-like growth factor-I
secretion in healthy young men.
Defining growth hormone
deficiency in adults.
Association of insulin-like
growth factor-I with body composition, weight history, and past health
behaviors in the very old: the Framingham Heart Study.
Insulin-like growth factor
measurements in the evaluation of growth hormone secretion.
IGF-I levels in different
conditions of low somatotrope secretion in adulthood: obesity in comparison
with GH deficiency.
Can IGF-1 production be
stimulated by factors other than GH?
The measurement of insulin-like
growth factor I: clinical applications and significance.
IGF-1 synthesis and release
Feeding colostrum increases
circulating insulin-like growth factor I in newborn pigs independent of
endogenous growth hormone secretion.
Independent effects of food
intake and insulin status on insulin-like growth factor-I in young pigs.
Clinical utility of insulin-like
growth factor assays.
Nutritional regulation of
insulin-like growth factor-I.
By what methods is IGF-1
measured?
Blood Panel
Saliva
Salivary insulin-like growth
factor-I originates from local synthesis.
normal population study of human
salivary insulin-like growth factor 1 (IGF 1) concentrations from birth
through puberty.
Free insulin-like growth factor I
(IGF-I) and IGF-II in human saliva.
Urine
Immunoreactive insulin-like
growth factor II in urine.
Urinary growth hormone excretion
in post-menarcheal adolescent girls with type 1 diabetes.
Changes in serum concentrations
of growth hormone, insulin, insulin-like growth factor and insulin-like
growth factor-binding proteins 1 and 3 and urinary growth hormone excretion
during the menstrual cycle.13
(IGFs) and IGF binding protein 3
in healthy volunteers before and after stimulation with recombinant human
growth hormone.
Cerebro Spinal Fluid
Specific assay for insulin-like
growth factor (IGF) II using the IGF binding proteins extracted from human
cerebrospinal fluid.
Amniotic Fluid
Insulin-like growth factors in
amniotic fluid.
Bile
Presence of insulin-like growth
factor I but absence of the binding proteins in the bile of rats.
Can IGF-1 be too high?
Prostate Cancer Risk
Insulin-like growth factor 1 and
prostate cancer risk: a population-based, case-control study.
Insulin-like growth factor 1 in
relation to prostate cancer and benign prostatic hyperplasia.
Breast Cancer Risk
The insulin-like growth factors
and breast cancer--revisited.
IGF-I physiology and breast
cancer.
Circulating concentrations of
insulin-like growth factor-I and risk of breast cancer.
Insulin and related factors in
pre menopausal breast cancer risk.
rBGH, IGF-1, and Cancer
(Think Before You Drink, by Ben
Davis, Conscious Choice, November/December 1995)
Insulin-like growth factor-I in
relation to pre menopausal ductal carcinoma in situations of the breast.
Other Important Blood Panel
biomarkers for GH production
Sex Hormones
Osteocalcin
BP3/BP2 Ratios (IGF-Binding
Proteins)
DHEA
Pregnenolone
Thyroid Stimulating Hormone
Thyroid, free T3
Thyroid, free T4
FSH
LH
Is Oral Growth Hormone Real or
Rip-Off?
Orally active growth hormone
secretagogues: state of the art and clinical perspectives.
Sample Standard Blood Panel
Protocol for measuring GH production
Hormonal Assays
The above analysis indicated
that IGF-1 is the ONLY true marker
of increased GH activity?
Our scientific team of
researchers, scientist's and formulators, disagree.
As members of the scientific
community, we answer this
resolution in the negative; no, IGF-1 is not recognized as the true
marker for GH activity.
We will use scientific abstracts
as our source of authority. They have the widest recognition and the highest
level of respect among the scientific community and they are supported by
the highest level of empirical data and research.
This resolution does not discern
whether or not IGF-1 is useful as one of several markers for GH activity,
which is widely known; it discerns IGF-1 as the ONLY marker for GH activity
and this is inherently wrong.
The question is, is IGF-1 considered by science to be the ONLY marker for GH
activity, not whether it is a marker or not.
This resolution also does not
concern the way in which IGF-1 is used as a marker for GH activity.
Introduction to what we
relegate to be fact.
The usefulness of IGF-1 as an
accurate and consistent measure of increased GH activity in the body has
been hotly debated in recent journals. The growing body of evidence did seem to
suggest that IGF-1 is not the only true marker of increased GH activity. In
fact, it is becoming increasingly clear to biochemists
worldwide that IGF-1 may not even be a "dependable" marker in measuring GH
activity since its production can be stimulated by factors other than GH
production. In the following sections, we will show that IGF-1 can be
effected by several events. Because of this, it is cautioned that anyone
seeking to understand true levels of GH activity should follow a full blood
panel protocol. Dependence on IGF-1 alone has been shown to give false
markers.
Is IGF-1 always increased by
increases in GH production?
It is well documented that IGF-1
levels can and do decrease in many cases, even when GH activity increases.
Please see the following medical journal excerpts.
Diagnosis of growth-hormone
deficiency in adults.
Hoffman DM, O'Sullivan AJ, Baxter
RC, Ho KK
Garvan Institute of Medical
Research, St Vincent's Hospital, Sydney, NSW, Australia.
There is no consensus as to the
most appropriate method of diagnosing growth-hormone (GH) deficiency in
adults. We have evaluated the relative diagnostic merits of measuring peak
GH response to insulin-induced hypoglycaemia (insulin tolerance test), mean
24 h GH concentration derived from 20 min sampling, serum insulin-like
growth factor I (IGF-I) concentrations, and serum IGF binding protein 3
(IGFBP-3) concentrations. These tests were undertaken in 23 patients
considered GH deficient from extensive organic pituitary disease, and in 35
sex-matched normal subjects of similar age and body-mass index.
Hypopituitary subjects had significantly lower stimulated peak GH, mean 24 h
GH, IGF-I, and IGFBP-3 concentrations than normal subjects. The ranges of
stimulated peak GH responses were clearly separated between the
hypopituitary (< 0.2-3.1 ng/mL) and normal (5.3-42.5 ng/mL) groups, but mean
24 h GH, IGF-I, and IGFBP-3 concentrations overlapped. Mean 24 h GH
concentrations were below assay sensitivity in 80% of hypopituitary subjects
and 16% of normal subjects. 70% and 72%, respectively, of the IGF-I and
IGFBP-3 values in hypopituitary subjects were within the range for normal
subjects. We conclude that GH deficiency in adults is most reliably
identified by stimulatory testing, and that IGF-I and IGFBP-3 are poor
diagnostic tests of adult GH deficiency…"
Serum Levels of Insulin-like
Growth Factor-I (IGF-I) and IGF Binding Protein-3 (IGFBP-3) in Idiopathic
Tall Basketball Players
G. E. Krassas, L. M. S. Carlsson,
C. Karlsson, N. Pontikides, Th. Kaltsas, R. Gunnarsson
"…On the basis of these results
one can hypothesize that IGF-I levels appear to reflect high physical
exercise and food intake rather than differences in GH secretion, while
IGFBP-3 reflects most probably differences in GH secretion and food intake…"
A five day treatment with daily
subcutaneous injections of growth hormone-releasing peptide-2 causes
response attenuation and does not stimulate insulin-like growth factor-I
secretion in healthy young men.
Nijland EA; Strasburger CJ; Popp
Snijders C; van der Wal PS; van der Veen EA
Department of Endocrinology, Free
University Hospital, Amsterdam, The Netherlands.
Eur J Endocrinol, 1998 Oct,
139:4, 395-401
"The synthetic hexapeptide growth
hormone-releasing peptide (GHRP)-2 specifically stimulates GH release in
man. To determine the effects of prolonged treatment and whether response
attenuation occurs in man, we administered to nine healthy subjects a daily
s.c. injection of 100 microg GHRP-2 over 5 days. Every day blood samples
were taken to determine GH, IGF-I, IGF-binding protein (IGFBP)-3 and
osteocalcin levels. On days 1,3 and 5, GH was measured at
-20,0,20,40,60,90,120 and 180 min using an immunometric and an
immunofunctional assay. Mean-/+S.D). peak GH concentrations were 83+/-31,
59+/-22 and 51+/-13 microg/l on days 1, 3 and 5 respectively. Mean+/-S.D.
areas under the curve for days 1, 3 and 5 were 6366+/-2514, 3987 +/- 1418
and 3392+/-1215 mU/l per min. Despite the maintained GH release, analysis of
variance revealed that significant response attenuation occurred (P < 0.01).
Mean serum IGF-I concentration did not increase after a 5 day treatment with
GHRP-2. Mean basal levels were 22, 25,23,25,23,24 nmol/l measured on days 1
to 6. However, osteocalcin, another serum marker of GH activity in tissue,
increased significantly from 3.2+/-1.0 to 4.2+/-0.4 microg/l (mean+S.D.) (P<
0.01)"
Defining growth hormone
deficiency in adults
Ho KK, Hoffman DM
Garvan Institute of Medical
Research, St. Vincent's Hospital, Sydney, Australia.
"The absence of a distinct
clinical syndrome calls for a strategy to reliably identify patients with
hyposomatotropism. However, there is no consensus as to the most appropriate
method of defining growth hormone (GH) deficiency in adults. Since GH
secretion falls with senescence and is also reduced by obesity, both of
these factors must be controlled for in such an evaluation. We have
investigated the relative diagnostic merits of measuring (1) peak GH
response to insulin-induced hypoglycemia (ITT), (2) mean 24-hour GH
concentration derived from 20-minute sampling (IGHC), (3) serum IGF-I
levels, and (4) serum insulin-like growth factor (IGF)-binding protein-3
(IGFBP-3) levels. These tests were undertaken in 23 patients considered GH-deficient
from extensive organic pituitary disease and in 35-sex-matched normal
subjects of similar age and body mass index. The ITT was the only test
capable of distinguishing patients with organic GH deficiency from matched
normal subjects. The sensitivity of the GH radioimmunoassay (0.2 ng/mL)
limited the utility of IGHC measurements, since many subjects from both
groups had undetectable values. Using a GH assay with a 100-fold greater
sensitivity, we found a better but still incomplete separation of values
between the two groups. There was a significant overlap of IGF-I and IGFBP-3
values, with only a third of GH-deficient subjects having low IGF-I values.
The limitation of IGF-I has been confirmed by others, although its
sensitivity as a diagnostic test is greater in young adults. We conclude
that organic GH deficiency in adults can be reliably diagnosed by the ITT"
Association of insulin-like
growth factor-I with body composition, weight history, and past health
behaviors in the very old: the Framingham Heart Study.
Harris TB; Kiel D; Roubenoff R;
Langlois J; Hannan M; Havlik R; Wilson P
National Institute on Aging,
Epidemiology, Demography and Biometry Program, Bethesda, MD 20892-9205, USA.
J Am Geriatric Soc, 1997 Feb,
45:2, 133-9
"CONCLUSION: Although IGF-I
declined with age, these data from the Framingham Heart Study did not show
expected cross-sectional associations of weight, body fat, and lean mass.
The strongest associations were between IGF-I and nutritional indicators.
These results suggest caution may be warranted with regard to use of IGF-I
as an indicator of growth hormone"
Insulin-like growth factor
measurements in the evaluation of growth hormone secretion
Furlanetto RW
"However, IGF-I levels are age
dependent and subject to regulation by other hormones and nutritional
variables; these features complicate the interpretation of IGF-I levels in
individual patients and limit the usefulness of these measurements,
particularly for determining GH deficiency in young children. Circulating
IGF-II levels are not GH dependent and, therefore, their measurement is of
little clinical utility in assessing GH secretion"
IGF-I levels in different
conditions of low somatotrope secretion in adulthood: obesity in comparison
with GH deficiency.
Maccario M, Grottoli S, Aimaretti
G, Gianotti L, Endrio Oleandri S, Procopio M, Savio P, Tassone F, Ramunni J,
Camanni F, Ghigo E
Department of Internal Medicine,
University of Turin, Italy.
"CONCLUSIONS: In conclusion,
present data confirm that IGF-I levels depends on GH secretion as well as on
nutritional status, being negatively and independently correlated with age
and BMI. IGF-I assay is not a reliable test for the diagnosis of GH
deficiency in adulthood though it gives good discrimination between GHD and
normal subjects up to 40 yrs of age. In spite of low GH secretion, IGF-I
levels are only slightly reduced in obesity, probably as consequence of
hyperinsulinism"
Can IGF-1 production be
stimulated by factors other than GH?
In this section, it will be shown
that IGF-1 can indeed be stimulated by factors other than GH production even
though among biochemists, it is used as the preliminary marker. However, the
growing body of respected science is moving away from IGF-1 as a reliable
marker of GH activity. Since the production of IGF-1 is "reactionary" to
other processes in the body, it can be stimulated by several factors that
are "mimetic." This means that if a substance that "mimes" GH is picked up
by the receptor sites of the Liver, it can trigger a rise in IGF-1
production without triggering a rise in GH production and therefore would
not give a reliable reading of increased GH production in those cases.
Nutrition and Amino Acid supplementation, in addition to protein intake can
stimulate the elevation of IGF-1 independent of GH increase. This may
indicate why IGF-1 levels rise in subjects ingesting "Amino Acid" growth
hormone products and this rise may not be indicative of actual GH rise. Some
Amino Acid precursors to GH actually increase IGF-1 production directly
without acting on GH.
The measurement of insulin-like
growth factor I: clinical applications and significance
Teale JD, Marks V
"Apart from GH control, several
other factors influence circulating IGF-I levels. Nutritional status can be
accessed through reference to IGF-I analysis, overall catabolic or anabolic
processes being associated with decreasing or increasing plasma IGF-I levels
respectively"
IGF-1 synthesis and release
Excerpted from the University of
Virginia Endocrinology syllabus
"…nutritional status is the
second most important regulator of IGF-1…" (GH release is the first)
Feeding colostrum increases
circulating insulin-like growth factor I in newborn pigs independent of
endogenous growth hormone secretion .
Wester TJ, Fiorotto ML, Klindt J,
Burrin DG
Children's Nutrition Research
Center, ARS, USDA, Department of Pediatrics, Baylor College of Medicine,
Houston, TX 77030, USA.
"Our objective was to examine the
influence of feeding and endogenous GH secretion on circulating IGF-I in
colostrum-deprived newborn pigs fed colostrum (n = 4), formula (control, n =
4), or water (n = 4). In another four formula-fed pigs, GH was ablated (GRF-A)
with two intravenous injections of a GH releasing-factor antagonist
(N-Ac-Tyr1,D-Arg2)-GRF(1-29)-NH2. Blood was serially sampled in all pigs to
measure plasma IGF-I and GH profiles. Feeding increased plasma IGF-I
concentration two- to fourfold and decreased GH secretion. Despite a more
than 80% decrease in the plasma GH in GRF-A pigs, the circulating IGF-I
concentration was similar to that in control pigs. In colostrum-fed pigs,
plasma IGF-I was higher than that in control pigs , despite equal nutrient
intake and lower circulating GH. There were no differences in plasma IGF
binding protein (IGFBP)-3 levels among the treatment groups. However, the
relative abundance of plasma IGFBP-4 was lower, and that of IGFBP-1 higher,
in unfed pigs than in any of the three fed groups. The plasma insulin
concentration was not different among fed pigs, but it was lower in unfed
pigs. Our results indicate that the circulating IGF-I concentration is more
dependent on nutrient intake than on GH in newborn pigs, despite relatively
high GH concentrations. However, because the nutrient content in the formula
was designed to match that of colostrum, a factor other than nutrient intake
and GH was responsible for the maximal increase in circulating IGF-I
concentration observed in colostrum-fed pigs"
Independent effects of food
intake and insulin status on insulin-like growth factor-I in young pigs
Taylor-Roth JL, Malven PV,
Gerrard DE, Mills SE, Grant AL
Lilly Research Laboratories,
Greenfield, IN 46140, USA.
"Reduction of food intake was
associated with decreased body weight gains, decreased serum IGF-I
concentrations, and increased serum GH concentrations. Nutrient restriction
also tended to decrease the relative abundance of IGF-I mRNA in liver and
skeletal muscle"
Clinical utility of insulin-like
growth factor assays
Lee PD, Rosenfeld RG
Department of Pediatrics,
Children's Hospital, Denver, Colo.
"Insulin-like growth I and II (IGF-I
and II) mediate many of the peripheral mitogenic actions of growth hormone (GH).
The marked dependence of IGF levels on GH adequacy has led to the
development of commercial immunoassays for IGF-I (somatomedin-C), and the
widespread use of IGF-I levels in the evaluation of short stature. Proper
interpretation of IGF-I levels requires consideration of assay methodology,
age-related norms, clinical findings, nutritional status, and concurrent
hormonal and disease processes. IGF-I levels alone cannot be used to predict
stimulated GH response, but may have value in directing the clinical
evaluation of a child with short stature. Low IGF-I levels may also be
characteristic of a subpopulation of short children with neurosecretory GH
deficiency. The role of IGF-II levels in the evaluation of short stature is
uncertain, although the combination of low IGF-I and IGF-II levels is more
specific for GH deficiency than either value alone. Other clinical
applications for IGF assays in pediatrics are also reviewed"
Nutritional regulation of
insulin-like growth factor-I
Ketelslegers JM, Maiter D, Maes
M, Underwood LE, Thissen JP
Department of Internal Medicine,
School of Medicine, Catholic University of Louvain, Brussels, Belgium.
"…Several lines of evidence
indicate that in the human, insulin-like growth factor-I (IGF-I) is
nutritionally regulated. Both energy and protein availability are required
for maintenance of IGF-I. Measurements of serum IGF-I constitute a sensitive
means for monitoring the response of acutely ill patients to nutritional
intervention. Serum IGF-I may also serve as a marker for evaluation of
nutritional status. Our findings and those of others in animal models
suggest that nutrients influence synthesis and action of IGF-I and its
binding proteins (IGFBPs) at multiple levels. In fasting, liver growth
hormone (GH) binding is decreased, providing one explanation for decreased
IGF-I. In protein restriction, GH receptors are maintained, but there is
evidence for a postreceptor defects. The latter results from
pretranslational and translational defects. Amino acid availability to the
hepatocytes is essential for IGF-I gene expression. Protein malnutrition not
only decreases IGF-I production rate, but also enhances its serum clearance
and degradation. Finally, there is evidence for selective organ resistance
to the growth-promoting effects of IGF-I in protein-restricted rats…"
By what methods is IGF-1
measured?
Blood Panel
It is already widely known that a
measure of serum IGF-1 can be accomplished by testing the blood. However,
testing IGF-1 alone is thought by many biochemists to be inadequate in
reflecting true GH levels.
Saliva
Salivary insulin-like growth
factor-I originates from local synthesis.
Ryan J, Mantle T, McQuaid S,
Costigan DC
Children's Research Centre, Our
Lady's Hospital for Sick Children, Crumlin, Dublin, Ireland.
"Insulin-like growth factor-I (IGF-I)
is a GH-dependent growth factor found in its highest concentrations in
plasma. It is also measurable in saliva. The origins of salivary IGF-I
concentrations were studied. Intracardial administration of Sprague-Dawley
rats with 125I-labelled IGF-I and subsequent analysis of plasma and saliva
samples by exclusion gel chromatography and SDS-PAGE, followed by
autoradiography, demonstrated the apparent inability of IGF-I to cross from
the plasma pool through to saliva. 125I-Labelled IGF-I was not
chromatographed immediately before injection, resulting in administration of
free iodide along with the iodinated peptide. This free iodide was
demonstrable in saliva, indicating that movement of substances from plasma
to saliva was measurable using the levels of 125I activity administered.
Free iodide in saliva was not contributed to by 125I-labelled IGF-I
degradation since 125I-labelled IGF-I was shown to be stable in saliva over
24 h. These data indicated that IGF-I in saliva is produced locally.
Identification of a 4.7 kb IGF-I mRNA transcript in rat parotid salivary
gland was consistent with IGF-I synthesis within that tissue"
Normal population study of human
salivary insulin-like growth factor 1 (IGF 1) concentrations from birth
through puberty.
Ryan J, Mantle T, Costigan DC
Children's Research Centre, Our
Lady's Hospital for Sick Children, Crumlin, Dublin, Ireland.
"Insulin-like growth factor 1 (IGF
1) concentrations in mixed saliva samples, collected from a normal
population (n = 327, ranging in age from birth to adolescence), were
determined by RIA . Salivary IGF 1 concentrations remained steady over a
24-h period when collected at basal rates, but were diminished in saliva
samples collected at a maximally stimulated flow rate. A similar pattern was
observed for males and females, when IGF 1 levels in saliva were plotted as
a function of age. The pattern was that of low levels in early childhood,
rising with age, peaking in puberty and falling again in late adolescence .
Salivary IGF 1 measurement differed from plasma measurement in three ways:
1) salivary IGF 1 concentrations (70 +/- 50 pM) were 100- to 200-fold less
than plasma IGF 1 levels; 2) salivary IGF 1 levels in age-matched male and
female samples were not different out side of pubertal influences; 3)
salivary IGF 1 levels in neonates were highly variable with concentrations
ranging up to pubertal concentrations. The study provides salivary IGF 1
reference data for a pediatric population"
Free insulin-like growth factor I
(IGF-I) and IGF-II in human saliva.
Costigan DC, Guyda HJ, Posner BI
Division of Endocrinology and
Metabolism, Montreal Children's Hospital-Research Institute, Quebec, Canada.
"… We found that human saliva
contains both insulin-like growth factor I (IGF-I) and IGF-II but no
significant binding proteins, and that salivary IGF-I levels correlated with
plasma GH levels. Mixed saliva had globular proteins precipitated by
freezing/thawing. After centrifugation the clear supernatant was used
directly in the IGF-I RIA (Van Wyk and Underwood antibody) and in a human
placental membrane RRA for IGF-II. The lower limits of detection for IGF-I
and IGF-II were 0.7 ng/mL (micrograms/L) and 1.2 ng/mL (micrograms/L),
respectively. Iodinated IGF added to saliva was not degraded, as assessed by
trichloroacetic acid precipitability and placental membrane binding. In
saliva from 14 normal subjects, IGF-I was measurable in all. IGF-II was
detectable only in 8 of 14 subjects; the mean value in these 8 subjects was
2.6 +/- 0.6 (+/- SE) ng/mL (micrograms/L). The mol wt of salivary IGF was
similar to that of free plasma IGF after acid or neutral pH gel
chromatography. Human saliva contained no significant IGF-binding protein.
Eluates from neutral gel chromatography of concentrated (20-fold) normal
saliva did not inhibit IGF-II binding to placental membrane receptors.
Eluted proteins from saliva samples subjected to prior acid gel
chromatography failed to bind radiolabeled IGF after neutralization. Saliva
samples assayed for binding protein using an amniotic fluid binding protein
RIA had values at or below the lower limit of detection [less than 0.06
micrograms eq/mL (mgeq/L)]. Salivary IGF-I concentrations did not change
with increasing salivary flow rates above normal, with time of day, or with
storage at room temperature for up to 24 h before freezing. The mean IGF-I
concentration in mixed saliva from 14 normal young adults (8 men) was 2.3
+/- 0.3 (+/- SE) ng/mL (micrograms/L), and their mean plasma IGF-I level was
315 +/- 27 ng/mL (micrograms/L). Mean salivary IGF-I was significantly lower
in 15 patients with GH deficiency [1.3 +/- 0.2 ng/mL (micrograms/L); P less
than 0.01] and 8-fold higher in 5 acromegalic patients [17.2 +/- 6.3 ng/mL
(micrograms/L); P less 0.01]. Removal of their GH adenomas led to a fall in
salivary IGF-I to 5.6 +/- 1.3 ng/mL (micrograms/L); P less than 0.05). In
summary, saliva contains free IGFs but no significant quantities of specific
binding proteins. Salivary IGF-I levels reflect the GH status of the donor…"
Urine
Immunoreactive insulin-like
growth factor II in urine.
Zumkeller W, Hall K
Department of Endocrinology,
Karolinska Hospital and Institute, Stockholm, Sweden.
"Insulin-like growth factor II
and insulin-like growth factor binding protein-1 were identified and
quantified in the urine of 23 healthy subjects between 17 and 76 years of
age. IGF-II was measured after separation by gel chromatography at low pH
and compared with IGF-I levels in the same samples, whereas IGF binding
protein-1 was measured in dialysed urine. Urinary IGF-II was found at much
higher concentrations than IGF-I (mean +/- SEM: 717 +/- 69 vs 110 +/- 5 ng/mmol
creatinine). The chromatographic profile indicates that pro-IGF-II may also
be present. The concentrations of IGF-II appear to be less variable than the
other reported parameters. The mean IGF binding protein-1 concentrations in
these urine samples was 414 +/- 83 ng/mmol creatinine. IGFs in the urine are
in part bound to binding proteins."
Urinary growth hormone excretion
in post-menarcheal adolescent girls with type 1 diabetes.
Aman J, Kroon M, Jones I,
Segnestam K, Snellman K
Department of Paediatrics, Orebro
Medical Centre Hospital, Sweden.
"The aim of the present study was
to compare measurements of urinary growth hormone (GH), serum insulin-like
growth factor I (IGF-I) and IGF binding protein 3 (IGFBP3) between two
groups of post-menarcheal girls, 13-18 y of age, one comprising 64 type 1
diabetic patients and the other 64 healthy girls matched for age and stage
of puberty. GH was determined on two occasions in nocturnal urine samples by
using a modification of an immunoradiometric method for serum. Significantly
higher urinary GH concentrations but lower IGF-I and IGFBP3 levels were
found in diabetic girls than in controls (p < 0.001). A significant
correlation was found between urinary GH concentrations and the daily dose
of insulin (U kg[-1]) (r = 0.426, p = 0.003). Urinary GH concentrations were
also significantly related to HbA1c (r = 0.380, p = 0.003). In conclusion,
disturbances of the GH-IGF-I axis may be evaluated by the use of
non-invasive urinary GH measurements, which is a simple alternative to
frequent sampling of serum GH. Increased GH secretion seems to be related to
a great need for insulin and poor metabolic control. More knowledge about
underlying causal factors in the disturbed GH-IGF-I axis is required"
Changes in serum concentrations
of growth hormone, insulin, insulin-like growth factor and insulin-like
growth factor-binding proteins 1 and 3 and urinary growth hormone excretion
during the menstrual cycle.
Juul A, Scheike T, Pedersen AT,
Main KM, Andersson AM, Pedersen LM, Skakkebaek NE
Department of Growth and
Reproduction, Rigshospitalet, Copenhagen, Denmark.
"Few studies exist on the
physiological changes in the concentrations of growth hormone (GH),
insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) within
the menstrual cycle, and some controversy remains. We therefore decided to
study the impact of endogenous sex steroids on the GH-IGF-IGFBP axis during
the ovulatory menstrual cycle in 10 healthy women (aged 18-40 years). Blood
sampling and urinary collection was performed every morning at 0800 h for 32
consecutive days. Every second day the subjects were fasted overnight before
blood sampling. Follicle stimulating hormone, luteinizing hormone (LH),
oestradiol, progesterone, IGF-I, IGFBP-3, sex hormone-binding globulin,
dihydroepiandrosterone sulphate and GH were determined in all samples,
whereas insulin and IGFBP-1 were determined in fasted samples only. Serum
IGF-I concentrations showed some fluctuation during the menstrual cycle,
with significantly higher values in the luteal phase compared to the
proliferative phase (P < 0.001). Mean individual variation in IGF-I
concentrations throughout the menstrual cycle was 13.2% (SD 4.3; range
0.1-18.3%). There were no cyclic changes in IGFBP-3 serum concentrations and
no differences in IGFBP-3 concentrations between the luteal and the
proliferative phases. Mean individual variation in IGFBP-3 concentrations
throughout the menstrual cycle was 8.8% (SD 2.7; range 3.2-14.1). IGFBP-1
concentrations were inversely associated with insulin concentrations, and
showed a significant pre-ovulatory increase that returned to baseline at the
day of the LH surge. Fasting insulin concentrations showed large
fluctuations throughout the menstrual cycle without any distinct cyclic
pattern. No cyclic changes in urinary GH excretion during menstrual cycle
were detected. We conclude that, although IGF-I concentrations are dependent
on the phase of the menstrual cycle, the variation in IGF-I concentrations
throughout the menstrual cycle is relatively small. Therefore, the menstrual
cycle does not need to be considered when evaluating IGF-I or IGFBP-3 serum
values in women suspected to have GH deficiency"
(IGFs) and IGF binding protein 3
in healthy volunteers before and after stimulation with recombinant human
growth hormone.
Tonshoff B, Blum WF, Vickers M,
Kurilenko S, Mehls O, Ritz E
Department of Pediatrics,
University Hospital of Heidelberg, Germany.
" We examined excretion of
urinary insulin-like growth factors I and II (IGF-I and IGF-II) and their
major binding protein IGFBP-3 in comparison to their respective serum
concentration in nine healthy female volunteers (median age 25 years, range
22-27) under baseline conditions and after stimulation with recombinant
human growth hormone (rhGH), 4.5 IU twice daily subcutaneously for a period
of 3 days. The IGFs were measured in unconcentrated urine by use of recently
developed, highly sensitive radioimmunoassays. The IGFBP-3 was measured by a
specific radioimmunoassay. The mean (+/- SD) urinary concentrations of IGF-I
(0.08 +/- 0.07 micrograms/l), IGF-II (1.02 +/- 0.47 micrograms/l) and
IGFBP-3 (19.1 +/- 6.9 micrograms/l) were two to three orders of magnitude
lower than in serum. The ratio of IGF-II over IGF-I concentration in urine
(13:1) was five times higher than in serum (2.5:1), and the ratio of IGFBP-3
over the sum of IGF-I and IGF-II in urine (17:1) was four times higher than
in serum (4:1). Urinary excretion was 63.3 +/- 46.6 ng.m-2.24h-1 for IGF-I,
1002 +/- 598 ng.m-2.24h-1 for IGF-II and 18039 +/- 4983 ng.m-2.24h-1 for
IGFBP-3. Using fast protein liquid exclusion chromatography, only
immunoreactive IGFBP-3 components of less than 60 kD were detected in urine,
with a major peak at 20 kD. Urinary IGFBP-3 excretion correlated with serum
IGFBP-3 (r = 0.61, p < 0.01) and the glomerular filtration rate (r = 0.56, p
< 0.05) measured by steady-state inulin infusion clearances"
Cerebro Spinal Fluid
Specific assay for insulin-like
growth factor (IGF) II using the IGF binding proteins extracted from human
cerebrospinal fluid.
Binoux M, Lassarre C, Gourmelen M
"A protein-binding assay for
insulin-like growth factor II (IGF II) is described. The assay uses IGF
binding proteins extracted from human cerebrospinal fluid which have
selective affinity for IGF II. IGF I was 9 times less potent than IGF II in
displacing [125I]IGF II, and when mixtures of the IGFs were assayed at IGF
I/IGF II ratios of 2, 5, and 10, interference from IGF I in the assay was
0%, 5%, and 9%, respectively. Given the serum concentrations of IGF I and
IGF II estimated by RIA and by this protein-binding assay, IGF I can be said
to have had no cross-reaction when IGF II was assayed in human serum and at
most 5% cross-reaction in the case of rat serum. After separation of IGFs
from their binding proteins by acidic gel filtration, serum IGF II levels
(mean +/- SE) measured by this method were 1322 +/- 66 ng/ml in normal
adults, 500 +/- 65 ng/ml in patients with total GH deficiency, 1327 +/- 69
ng/ml in untreated acromegalic patients, and 1817 +/- 145 ng/ml in uremic
patients undergoing chronic hemodialysis. In postpubertal young rats, the
mean serum IGF II level was 43 +/- 2.6 ng/ml and after hypophysectomy it was
16 +/- 2.4 ng/ml. Although the IGF II levels in man and in the rat were
different, they appeared to be similarly GH dependent, although less so than
IGF I. In view of the sensitivity (0.03 ng IGF II) and the specificity of
this assay, the small quantities of cerebrospinal fluid required (1 mu leq/assay
tube) and its applicability for IGF II measurement in several species, the
use of this assay for measuring IGF II in a variety of biological media can
be envisaged"
Amniotic Fluid
Insulin-like growth factors in
amniotic fluid.
Merimee TJ, Grant M, Tyson JE
"The concentrations of
insulin-like growth factors I and II (IGF-I and IGF-II) in amniotic fluid
were determined by specific immunoassays in 58 women. IGF-I concentrations
were constant throughout gestation at approximately 20 ng/ml; the mean IGF-II
concentration was 114 +/- 13 (+/- SE) ng/ml at the earliest period of
gestation studied and remained unchanged at 26 to 33 weeks despite a greater
than 50% decrease in amniotic fluid total protein. A precipitous decrease in
IGF-II concentration occurred at term which was not explainable by
alterations in total amniotic fluid protein concentration. The
concentrations of IGF-I and IGF-II in amniotic fluid did not correlate with
concentrations of these factors in maternal serum (r = 0.08 and 0.09,
respectively). [125I]IGF-I and [125I]IGF-II, after incubation with amniotic
fluid, bound to a 40-45 K protein (or proteins). A carrier protein of
greater mol wt, as in serum, was not detected. These findings indicate that
there is dynamic control of IGF in amniotic fluid during normal pregnancy"
Bile
Presence of insulin-like growth
factor I but absence of the binding proteins in the bile of rats.
Kong W, Philipps AF, Dvorak B,
Anderson GG, Lake M, Koldovsky O
Department of Pediatrics, Steele
Memorial Children's Research Center, Furrow Research Laboratory, University
of Arizona College of Medicine, Tucson 85724.
"Whereas insulin-like growth
factor I (IGF-I) has been found in various body fluids from different
species, the presence or absence of IGF and associated binding proteins (IGFBPs)
in bile has not been clearly defined. Bile concentration of IGF-I was
measured in this study and found to be highest in the neonate and lowest in
adult rats [133 +/- 15.9, 79.4 +/- 10.5, 45.3 +/- 12.7 ng/ml (mean +/- SE)
in 12-day-old, 33-day-old, and adult rats, respectively]. When bile delivery
rates of IGF-I (i.e., the product of IGF-I concentration in bile and the
biliary flow rate) were calculated, IGF-I delivery was highest in weanling
rats (469 pg.h-1.g body wt-1). When expressed as amount of IGF-I in bile
delivered per day, however, delivery rates rose from 0.2 micrograms/day in
the suckling and remained constant at 1.6-1.7 micrograms/day in both
weanling and adult animals. Bile samples exposed to a placental membrane IGF
receptor preparation showed significant dose-dependent inhibition of binding
of native IGF-I. Because no IGF binding proteins were identified by Western
ligand blot or by Sephadex gel chromatography, the results suggest the
presence of biologically significant quantities of bioactive IGF-I in bile.
We speculate that IGF-I in bile may play an important role in the growth of
the gastrointestinal tract, both in the suckling as well as later in life"
Can IGF-1 be too high?
Prostate Cancer Risk
Insulin-like growth factor 1 and
prostate cancer risk: a population-based, case-control study.
Wolk A, Mantzoros CS, Andersson
SO, Bergstrom R, Signorello LB, Lagiou P, Adami HO, Trichopoulos D
Department of Medical
Epidemiology, Karolinska Institute, Stockholm, Sweden. Alicja.Wolk@mep.ki.se
"BACKGROUND: Recent epidemiologic
investigations have suggested an association between increased blood levels
of insulin-like growth factor 1 (IGF-1) and increased risk of prostate
cancer. Our goal was to determine whether an association exists between
serum levels of IGF-1 and one of its binding proteins, insulin-like growth
factor-binding protein 3 (IGFBP-3), and prostate cancer risk. METHODS: An
immunoradiometric assay was used to quantify IGF-1 levels and IGFBP-3 levels
in serum samples as part of a population-based, case-control study in
Sweden. The study population comprised 210 patients with newly diagnosed,
untreated prostate cancer and 224 frequency-matched control subjects. Data
were analyzed by use of unconditional logistic regression to calculate odds
ratios (ORs) and 95% confidence intervals (CIs). Reported P values are two-
sided. RESULTS: The mean serum IGF-1 level for case patients (158.4 ng/mL)
was significantly higher than that for control subjects (147.4 ng/mL) (P =
.02); corresponding mean serum IGFBP-3 levels were not significantly
different between case patients (2668 ng/mL) and control subjects (2518 ng/mL)
(P =.09). We found a moderately strong and statistically significant (P =
.04) positive association between serum levels of IGF-1 levels and risk of
prostate cancer (OR = 1.51; 95% CI = 1.0-2.26 per 100 ng/mL increment); the
association was particularly strong for men younger than 70 years of age (OR
= 2.93; 95% CI = 1.43-5.97). No association was found between serum IGF-1
levels and disease stage. Serum IGFBP-3 levels were not significantly
associated with increased risk of disease, and adjustment for IGFBP-3 had
little effect on the association between IGF-1 levels and risk of prostate
cancer. CONCLUSION: Elevated serum IGF-1 levels may be an important
predictor of risk for prostate cancer. However, our results do not support
an important role for serum IGFBP-3 as a predictor of risk for this disease"
Insulin-like growth factor 1 in
relation to prostate cancer and benign prostatic hyperplasia.
Mantzoros CS, Tzonou A,
Signorello LB, Stampfer M, Trichopoulos D, Adami HO
Department of Epidemiology and
Harvard Center for Cancer Prevention, Harvard School of Public Health,
Boston, Massachusetts 02115, USA.
"Blood samples were collected
from 52 incident cases of histologically confirmed prostate cancer, an equal
number of cases of benign prostatic hyperplasia (BPH) and an equal number of
apparently healthy control subjects. The three groups were matched for age
and town of residence in the greater Athens area. Steroid hormones, sex
hormone-binding globulin, and insulin-like growth factor 1 (IGF-1) were
measured in duplicate by radioimmunoassay in a specialized US centre.
Statistical analyses were performed using multiple logistical regression.
The results for IGF-1 in relation to prostate cancer and BPH were adjusted
for demographic and anthropometric factors, as well as for the other
measured hormones. There was no relation between IGF-1 and BPH, but
increased values of this hormone were associated with increased risk of
prostate cancer; an increment of 60 ng ml(-1) corresponded to an odds ratio
of 1.91 with a 95% confidence interval of 1.00-3.73. There was also some
evidence for an interaction between high levels of testosterone and IGF-1 in
relation to prostate cancer. This finding suggests that, in addition to
testosterone, IGF-1 may increase the risk of prostate cancer in humans"
Breast Cancer Risk
It has been consistently shown
that sustained rises in IGF-1, rises like those claimed by amino acid based,
IGF-1 stimulating HGH products, can contribute to a heightened risk of
Breast, Colon and Pancreatic cancers among others. Please see the following
abstracts.
The insulin-like growth factors
and breast cancer-revisited.
Yee D
University of Texas Health
Science Center at San Antonio, 78284-7884, USA. yeed@uthscsa.edu
"In 1992, a special issue of
Breast Cancer Research and Treatment was devoted to the insulin-like growth
factors and breast cancer. In that issue, identification of the key
components of the IGF system was reviewed and their potential role in breast
cancer growth was described. In this issue, we revisit the IGF system with
particular attention to data that further supports their role in the growth
regulation of breast cancer. Several new facets of the IGF system are
described, and several laboratories have more clearly defined how each
individual component of the IGF system may influence breast cancer biology"
IGF-I physiology and breast
cancer.
Pollak M
Department of Medicine, McGill
University, Montreal, Quebec, Canada.
"Recent studies imply that IGF-I
levels vary greatly between normal women, and that premenopausal breast
cancer risk is increased among women with higher IGF-I levels. It is known
that tamoxifen lowers IGF-I levels, but further research is needed to
determine whether antiestrogens will be of particular value in risk
reduction for women with high IGF-I levels, and also to determine if IGF-I
levels can indeed be used as an intermediate endpoint in risk reduction
interventions. With respect to adjuvant therapy, we currently have
convincing data that antiestrogens have moderate IGF-I lowering actions, but
it remains unclear to what extent these contribute to the therapeutic effect
of these compounds. Ongoing trials are addressing this question, as well as
the hypothesis that interventions that increase IGF-I suppression will be
associated with reduced relapse rates "
Circulating concentrations of
insulin-like growth factor-I and risk of breast cancer.
Hankinson SE, Willett WC, Colditz
GA, Hunter DJ, Michaud DS, Deroo B, Rosner B, Speizer FE, Pollak M
Channing Laboratory, Brigham and
Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
"BACKGROUND: Insulin-like growth
factor (IGF)-I, a mitogenic and antiapoptotic peptide, can affect the
proliferation of breast epithelial cells, and is thought to have a role in
breast cancer. We hypothesised that high circulating IGF-I concentrations
would be associated with an increased risk of breast cancer. METHODS: We
carried out a nested case-control study within the prospective Nurses'
Health Study cohort. Plasma concentrations of IGF-I and IGF binding protein
3 (IGFBP-3) were measured in blood samples collected in 1989-90. We
identified 397 women who had a diagnosis of breast cancer after this date
and 620 age-matched controls. IGF-I concentrations were compared by logistic
regression with adjustment for other breast-cancer risk factors. FINDINGS:
There was no association between IGF-I concentrations and breast-cancer risk
among the whole study group. In postmenopausal women there was no
association between IGF-I concentrations and breast-cancer risk (top vs
bottom quintile of IGF-I, relative risk 0.85 [95% CI 0.53-1.39]). The
relative risk of breast cancer among premenopausal women by IGF-I
concentration (top vs bottom tertile) was 2.33 (1.06-5.16; p for trend
0.08). Among premenopausal women less than 50 years old at the time of blood
collection, the relative risk was 4.58 (1.75-12.0; p for trend 0.02). After
further adjustment for plasma IGFBP-3 concentrations these relative risks
were 2.88 and 7.28, respectively. INTERPRETATION: A positive relation
between circulating IGF-I concentration and risk of breast cancer was found
among premenopausal but not postmenopausal women. Plasma IGF-I
concentrations may be useful in the identification of women at high risk of
breast cancer and in the development of risk reduction strategies.
Additional larger studies of this association among premenopausal women are
needed to provide more precise estimates of effect"
Insulin and related factors in
premenopausal breast cancer risk.
Del Giudice ME, Fantus IG, Ezzat
S, McKeown-Eyssen G, Page D, Goodwin PJ
Mount Sinai Hospital, Division of
Clinical Epidemiology of the Samuel Lunenfeld Research Institute, Toronto,
Ontario, Canada.
"BACKGROUND: Insulin and
insulin-like growth factor I (IGF-I) are important mitogens in vitro and in
vivo. It has been hypothesized that these factors may play an important role
in the development of breast cancer. METHODS: A case-control study comparing
plasma insulin levels in 99 premenopausal women with newly diagnosed
node-negative invasive carcinoma of the breast and 99 age-matched controls
with incident biopsied non-proliferative breast disease (NP) was conducted.
Women with known diabetes were excluded. RESULTS: For the entire study
group, mean age was 42.6 +/- 5.1 years and mean weight was 62.9 +/- 10.3 kg.
After adjustment for age and weight, elevated insulin levels were
significantly associated with breast cancer, Odds Ratio (OR) for women in
the highest insulin quintile versus the lowest quintile = 2.83 (95%
Confidence Interval [CI] 1.22-6.58). There were no statistically significant
differences between cases and controls for IGF-I and IGFBP-1 levels.
However, after adjustment for age, the association between plasma levels of
insulin-like growth factor binding protein 3 (IGFBP-3) and breast cancer
approached statistical significance; OR for highest quintile versus lowest
quintile of IGFBP-3 being 2.05 (95% CI, 0.93-4.53). All results were
independent of diet and other known risk factors for breast cancer.
CONCLUSION: Circulating insulin levels and possibly IGFBP-3 levels are
elevated in women with premenopausal breast cancer. This association may
reflect an underlying syndrome of insulin resistance that is independent of
obesity"
rBGH, IGF-1, and Cancer
(Think Before You Drink, by Ben
Davis, Conscious Choice, November/December 1995)
"In addition to the unusual
growth patterns IGF-1 seems to promote, there is strong evidence of a cancer
risk from IGF-1. Science Magazine recently reported that IGF-1 increases the
malignancy of human breast cancer cells, including their invasiveness and
ability to spread to distant organs. A study in the New England Journal of
Medicine confirmed that growth factors such as IGF-1 are responsible for the
promotion of breast cancer cells. IGF-1 has been similarly linked with colon
cancer." "A leading British medical journal recently reported that the
breast cells of fetuses and infants are particularly susceptible to hormonal
influences. Such imprinting by IGF-1 may increase future breast cancer
risks, and may also increase the sensitivity of the breast to subsequent
unrelated risks such as mammography and the carcinogenic and estrogen-like
effects of pesticide residues in food, particularly in pre-menopausal
women…" "…Excessive IGF-1 also wreaks havoc on the gastro-intestinal tract.
A recent study on acromegaliacs--people who suffer from excessive growth of
the their head, hands, face, and feet--shows that they have a higher
incidence of tumors in the colon (a portion of the intestines).
Acromegaly
is caused by an excessive amount of natural IGF-1 in the human body. In
another recent study, IGF-1 was exposed to human cells taken from the human
gut. The study reported that IGF-1 promoted cell division." "Another recent
study published in Cancer Research shows clearly that IGF-1 is required for
the establishment and maintenance of tumors. This study found that IGF-1
protects the cells from programmed cell death. IGF-1 was shown to accelerate
tumor growth and effect the aggressiveness of tumors. As IGF-1 levels were
decreased, cell death took place"
Insulin-like growth factor-I in
relation to pre menopausal ductal carcinoma in situ of the breast.
Bohlke K, Cramer DW, Trichopoulos
D, Mantzoros CS
Department of Epidemiology,
Harvard School of Public Health, Boston, MA, USA.
"We evaluated the association of
plasma insulin-like growth factor-I (IGF-I) and IGF binding protein-3
(IGFBP-3) with risk of breast cancer in a study of 94 cases of premenopausal
ductal carcinoma in situ and 76 controls. Compared with women in the lowest
tertile of IGF-I, women in the upper two tertiles of IGF-I had an elevated
risk for ductal carcinoma in situ. Conversely, compared with women in the
lowest tertile of IGFBP-3, women in the upper two tertiles of IGFBP-3 had a
decreased risk for ductal carcinoma in situ. After grouping women on the
basis of both IGF-I and IGFBP-3, women in the highest two tertiles of IGF-I
and the lowest tertile of IGFBP-3 were at notably higher risk than women in
the lowest tertile of IGF-I and the highest two tertiles of IGFBP-3 (odds
ratio = 3.7; 95% confidence interval = 1.1-12.2). We conclude that the
combination of high IGF-I and low IGFBP-3 may increase the risk of
premenopausal ductal carcinoma in situ"
Other Important Blood Panel
biomarkers for GH production
Sex Hormones
Osteocalcin
BP3/BP2 Ratios (IGF-Binding
Proteins)
DHEA
Pregnenolone
Thyroid Stimulating Hormone
Thyroid, free T3
Thyroid, free T4
FSH
LH
Is Oral Growth Hormone Real or
Rip-Off?
Orally active growth hormone
- secretagogue: state of the art and clinical perspectives.
Ghigo E, Arvat E, Camanni F
Department of Internal Medicine,
University of Turin, Italy.
"Growth hormone secretagogues (GHS)
are synthetic, non-natural peptidyl and nonpeptidyl molecules with potent
stimulatory effect on somatotrope secretion. They have no structural
homology with growth hormone-releasing hormone (GHRH) and act via a specific
receptor, which has now been cloned and is present at both the pituitary and
hypothalamic level. This evidence strongly suggests the existence of a still
unknown natural GHS-like ligand. Several data references favor the
hypothesis that GHS could counteract somatostatinergic activity at both the
pituitary and hypothalamic level and/or, at least partially, via a GHRH-mediated
mechanism. However, the possibility that they act via an unknown
hypothalamic factor remains open. GH-releasing peptide-6 (GHRP-6) is the
first hexapeptide studied extensively in humans. More recently, peptidyl
superanalogues GHRP-1, GHRP-2 and hexarelin, and nonpeptidyl mimetics, such
as the spiroindoline derivative MK-677, have been synthesized and their
effects have been studied in humans. The GH-releasing activity of GHS is
marked, dose related and reproducible after intravenous, subcutaneous,
intranasal and even oral administration. The effect of GHS is partially
desensitized but prolonged, intermittent oral administration increases
insulin-like growth factor I (IGF-I) levels. The GH-releasing effect of GHS
undergoes age-related variations; it increases from birth to puberty,
remains similar in adulthood and decreases with ageing. The effect of GHS on
GH release is synergistic with that of GHRH, while it is only partially
refractory to inhibitory influences, which nearly abolish the effect of GHRH.
GHS maintain their GH-releasing activity in some somatotrope hypersecretory
states such as acromegaly, anorexia nervosa, hyperthyroidism and critical
illness. The GH response to GHS has been reported clear although reduced in
GH deficiency, obesity and hypothyroidism, while it is strongly reduced in
patients with pituitary stalk disconnection or Cushing's syndrome. In short
children, elderly subjects, critically ill patients and even in adult
patients with GH deficiency an increase of IGF-I has been shown after GHS
treatment. These data indicate that treatment with orally active GHS in
humans enhances the activity of the GH-IGF-I axis and could be clinically
useful"
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[disclaimer] “These statements have not
been evaluated by FDA. Products or treatment reflected on this website are not intended to diagnose, treat, cure or
prevent any disease.”
Because of the unscrupulous advertising practices from the manufacturers of
inferior dietary products, the FDA & FTC have made it clear that we may use the
correct printed information that indicates rGH spray is indeed Growth Hormone on
our website but that no-one may use the word Growth Hormone on the bottle
containing the product for sale to the public; because we must fly under the
radar screen. We must use Growth Factor instead, which is perfectly acceptable.
We must also place the following statement on our website:
These statements have not been evaluated by the FDA and are not intended to
diagnose, treat, cure, mitigate or prevent any disease.
OverTheCounter
Rejuvenis Max is produced according to the guidelines of the
Homeopathic Pharmacopeia of the United States.
Furthermore, with respect to our Rejuvenis Max and Somastatin products, in order
to comply with current FTC requirements, we must state all anti-aging benefits
mentioned are associated with the injectable form of somatotropin and not our
OTC HPUS products
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