Hello,
Thanks for asking your question. You asked the following:
"i am worried about acromeglia(when ur face start to look like a
giant)! are there any blood tests to show if i am ok or is 330 a good
level to have??"
Here are a few words about IGF-1 testing from the Anti-Aging
Institute:
"IGF-1 is Insulin-Like Growth Factor that is formed by liver cells
when they are stimulated by Human Growth Hormone (HGH). It is the
compound that is responsible for the effects we see from HGH
supplementation. It is also known as Somatomedin-C.
The ideal target for IGF-1 should be 280-400 mcg/ml (slightly higher
in females). Normally, this is the value for 20-25 year olds. We find
there is a wide variety of levels based on life-style and diet.
Generally the normal values drop about 10% per decade."
http://www.anti-aging.org/igf.html
Your level of 330 falls within the normal range of IGF-1 (280-400).
If you are on hormone therapy, you should check your level every 3-6
months. The obvious side effect of an increased IGF level are the
effects associated with acromegaly.
Acromegaly results from persistent hypersecretion of growth hormone
(GH). The excess GH stimulates the hepatic secretion of insulin-like
growth factor-I (IGF-I), which causes most of the clinical
manifestations of acromegaly.
Both serum GH concentrations and IGF-I concentrations are increased in
virtually all patients with acromegaly.
From UptoDate:
"The best single test for acromegaly is measurement of serum IGF-I.
Unlike growth hormone, serum IGF-I concentrations do not vary from
hour to hour according to food intake, exercise or sleep, but instead
reflect integrated GH secretion during the preceding day or longer.
Serum IGF-I concentrations are elevated in virtually all patients with
acromegaly and provide excellent discrimination from normal
individuals.
The results must be interpreted, however, according to the patient's
age. In normal subjects, serum IGF-I concentrations are highest during
puberty and decline gradually thereafter. Values are significantly
lower in adults over the age of 60 than in younger subjects. Thus, an
apparently "normal" value in a patient aged 70 years may in fact be
elevated." (1)
I will now briefly discuss some features of an increased IGF-1/growth
hormone level, so you can be on the lookout for these symptoms while
on hormone therapy.
The clinical features of acromegaly are attributable to high serum
concentrations of both GH and insulin-like growth factor-I (IGF-I),
which is GH-dependent. Excess GH and IGF-I have both somatic and
metabolic effects. The onset of acromegaly is insidious, and its
progression is usually very slow. The interval from the onset of
symptoms until diagnosis is about 12 years.
The characteristic findings are an enlarged jaw (macrognathia) and
enlarged, swollen hands and feet, which result in increasing shoe and
glove size and the need to enlarge rings. The facial features become
coarse, with enlargement of the nose and frontal bones as well as the
jaw, and the teeth become spread apart. Joint symptoms are a common
presenting feature of the disease, and back pain (and kyphosis) is
common. Cardiovascular abnormalities include hypertension, left
ventricular hypertrophy, and cardiomyopathy. The skin thickens, making
it hard to puncture, and skin tags may appear. Manifestations of soft
tissue overgrowth include macroglossia, deepening of the voice, and
paresthesias of the hands (eg, carpal tunnel syndrome in around 20
percent).
Acromegaly is associated with an increased risk of uterine leiomyomata
and perhaps also colonic polyps. An increased incidence of several
kinds of cancer has been suspected in acromegaly, but most studies
have been uncontrolled. Approximately 10 percent of acromegalic
patients develop malignant tumors, including adenocarcinomas of the
colon, stomach, and esophagus, and melanoma (2). Many visceral organs
are enlarged in acromegaly, including the thyroid, heart, liver,
kidneys, and prostate. The thyroid enlargement may be diffuse or
multinodular. Fatigue and weakness can be prominent symptoms. They may
result from sleep apnea, cardiovascular dysfunction, neuropathy,
hypogonadism, hyperglycemia, or some combination of these factors.
The mortality rate of patients with acromegaly is two to three times
the expected rate, mostly from cardiovascular diseases and cancer (3).
It is good to see that you are concerned about the IGF-1 level.
Currently you level of 330 falls within the normal range (280-400).
As you can see, having a chronically elevated IGF-1 level is hazardous
to your health - I have described many of these effects above. You
should continue to monitor your IGF-1 level periodically.
"Are there any blood tests to show if i am ok?"
There are several blood tests to determine a diagnosis of acromegaly.
This can be confirmed by measurement of both serum GH concentration
after a glucose load and GH-dependent circulating molecules, such as
IGF-I and IGFBP-3.
I stress that this answer is not intended as and does not substitute
for medical advice - please see your primary care physician for
further evaluation of your individual case.
Please use the answer clarification to ask any questions before rating
this answer. I will be happy to explain any issue.
Thanks,
Kevin, M.D.
Search strategy:
No internet search engine was used in this answer. All sources are
from objective, physician-written, peer-reviewed resources.
Bibliography:
1) Melmed. Diagnosis of acromegaly. UptoDate, 2002.
2) Ron, E, Gridley, G, Hrubec, Z, et al. Acromegaly and
gastrointestinal cancer. Cancer 1991; 68:1673.
3) Wright, AD, Hill, DM, Lowy, C, et al. Mortality in acromegaly. Q J
Med 1970; 39:1.
4) Melmed. Clinical manifestations of acromegaly. UptoDate, 2002.
Links:
NIDDK - Acromegaly
http://www.niddk.nih.gov/health/endo/pubs/acro/acro.htm#diagnosed
The Anti-Aging Institute - Questions about IGF-1 Testing
http://www.anti-aging.org/igf.html
Lab Tests Online - Growth Hormone
http://labtestsonline.org/understanding/analytes/growth_hormone/glance.html |
Clarification of Answer by
kevinmd-ga
on
05 Feb 2003 18:12 PST
Hello,
Thanks for asking for clarification.
"So i should be ok with a igf-1 of 330?"
Currently, your IGF-1 level of 330 falls within the normal range of
IGF-1 (280-400).
"Explain the other blood test to me in detail please."
1) Serum GH concentration
Measurement of serum growth hormone is indicated in patients with
equivocal serum IGF-I values, or in those with elevated serum IGF-I
values in whom further biochemical confirmation is required. GH
secretion in normal subjects is pulsatile, diurnal, and stimulated by
a variety of factors, including short-term fasting, exercise, stress,
and sleep. As a result, serum GH concentrations fluctuate widely,
ranging from less than 0.5 to 1 ng/mL (less than 0.1 ng/mL using very
sensitive assays) during most of the day, to 2 to 5 ng/mL before the
next meal or after exercise, to as high as 20 or 30 ng/mL at night or
after vigorous exercise. Serum GH concentrations also may be high in
patients with uncontrolled diabetes mellitus, liver disease, and
malnutrition.
All patients with acromegaly have increased GH secretion. However, the
serum GH concentration is often in the range of 2 to 10 ng/mL during
much of the day, values that can be found in normal subjects. Unlike
normal subjects, the patient's serum GH concentrations change little
during the day or night, and in most patients do not change in
response to stimuli such as food or exercise. Nevertheless, because of
the variations in serum GH that occur in normal subjects and in
patients with other disorders, a high value cannot be interpreted
without knowing when the blood sample was obtained and something about
the patient. To obviate these problems it is best not to obtain random
measurements of serum GH.
The most specific dynamic test for establishing the diagnosis of
acromegaly is an oral glucose tolerance test. In normal subjects,
serum GH concentrations fall to 2 ng/mL or less within two hours after
ingestion of 50 to 100 g glucose. In contrast, the post-glucose values
are greater than 2 ng/mL in over 85 percent of patients with
acromegaly.
2) Serum IGFBP-3 concentration
Because IGFBP-3 secretion is GH-dependent (as is IGF-I), serum IGFBP-3
concentrations are elevated in patients with acromegaly. There is,
however, considerable overlap of these values with those in normal
persons, thereby limiting the utility of this measurement.
Based on this, it would seem that the serum growth hormone (GH) and
the IGF-1 are the two more important tests in diagnosing acromegaly.
Thanks,
Kevin, M.D.
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Clarification of Answer by
kevinmd-ga
on
07 Feb 2003 19:46 PST
Hello - thanks for the opportunity to answer your further questions.
1) does growth hormones increase testosterone?
Yes - regarding IGF-1 specifically. As you know IGF-1 is a reflection
of growth hormone. From UptoDate:
"IGF-I stimulates specialized functions in endocrine tissues,
including enhancement of the effects of FSH and LH on production of
steroids by ovarian granulosa cells, testosterone secretion by Leydig
cells, the effects of ACTH on adrenal cortical cell steroidogenesis,
and the response of thyroid follicular cells to TSH." (1)
2) does it increase estrogen?
Yes. It was mentioned above that IGF-1 increases the effects of FSH
(follicle stimulating hormone). An increased FSH increases estrogen
level - this is more pronounced in women than in men. From the Center
of Male Reproductive Medicine:
"Since men with idiopathic infertility have normal testosterone
levels, by definition, the increased FSH, LH and testosterone that
result from clomiphene or tamoxifen treatment may boost testosterone
and estrogen levels above normal levels."
http://www.maleinfertility.org/new-therapy.html#anti
For the next 2 questions, there are conflicting studies - there is no
consensus. I will give studies that say IGF-1 both promotes hair
growth and loss.
3) does it promote hair growth?
Possibly. In a study by Su et al. (1999), it is suggested that IGF-1
may stimulate hair follicle cells and has a role in anti-apoptosis
(i.e. self-destruction):
"IGF-1 may therefore be able to stimulate the proliferation of hair
follicle cells through cellular signaling pathways of its receptors.
Local infusion of IGF-1 into sheep has been reported to be capable of
stimulating protein synthesis in the skin. It may also increase the
production of wool keratin. The anti-apoptotic role of IGF-1 in hair
follicles is also reviewed." (3)
In another study by Philpott et al. (1994), he suggests that IGF-1
stimulates hair follicle growth:
"Both IGF-I (0.01-100 ng/ml) and IGF-II (0.01-100 ng/ml) stimulated
hair follicle growth in a dose-dependent manner." (4)
4) does it promote hair loss?
Possibly. A study by Signorello et al. (1999) suggests that a higher
IGF-1 level doubles the incidence of vertex baldness:
"BACKGROUND: Androgens are important in hair growth and patterning,
whereas growth hormone substitution enhances their effect in growth
hormone-deficient men. No previous study has jointly evaluated the
function of sex steroids, sex hormone-binding globulin (SHBG), and
insulin-like growth factor (IGF-1) in determining hair patterning in
men. OBJECTIVE: We assessed the relationship between circulating
hormone measurements and both head and chest hair patterning in a
sample of elderly men. METHODS: Fifty-one apparently healthy men older
than 65 years of age were studied cross-sectionally. Head and chest
hair patterning was assessed by a trained interviewer. Morning blood
samples from all subjects were used for measurements of testosterone,
estradiol, dehydroepiandrosterone sulfate, SHBG, and IGF-1. RESULTS:
Results were obtained from logistic regression models, adjusting
simultaneously for all the measured hormones and age. Men with higher
levels of testosterone were more likely to have vertex baldness (odds
ratio [OR] = 2.5, 95% confidence interval [CI: 0.9 to 7.8] per 194
ng/dL increment of testosterone). In addition, for each 59 ng/mL
increase in IGF-1, the odds of having vertex baldness doubled (95% CI
[1.0 to 4.6]). Those who were found to have higher circulating levels
of SHBG were less likely to have dense hair on their chest (OR = 0.4,
95% CI [0.1 to 0.9] per 24 nmol/L increment in SHBG]). CONCLUSION:
Testosterone, SHBG, and IGF-1 may be important in determining hair
patterning in men." (2)
I hope that this information helps. Please feel free to contact me
should you have any further questions.
Thanks,
Kevin, M.D.
Bibliography:
1) Clemmons. Physiology if IGF-1. UptoDate, 2002.
2) Signorello LB, Wuu J, Hsieh C, Tzonou A, Trichopoulos D, Mantzoros
CS.
Hormones and hair patterning in men: a role for insulin-like growth
factor 1?
J Am Acad Dermatol. 1999 Feb;40(2 Pt 1):200-3.
3) Su HY, Hickford JG, Bickerstaffe R, Palmer BR. Insulin-like growth
factor 1 and hair growth. Dermatol Online J. 1999 Nov;5(2):1.
4) Philpott MP, Sanders DA, Kealey T. Effects of insulin and
insulin-like growth factors on cultured human hair follicles: IGF-I at
physiologic concentrations is an important regulator of hair follicle
growth in vitro.
J Invest Dermatol. 1994 Jun;102(6):857-61.
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