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The GH, IGF-1, and IGFBP-3; The Relationship
Growth Hormone: The half-life of human
growth hormone in serum is about 20 minutes making it an unreliable hormone to measure on a random basis since its measurement
represents a snapshot of the blood.
Urine Growth Hormone: Either by 24
hour or first morning urine testing the level of human growth hormone can be accurately measured. This mode of
testing in conjunction with IGF-1 and IGFBP-3 is gaining ground as a reproducable means of diagnosing Adult Growth Hormone
Deficiency.
Insulin-like Growth Factor-1: The
half-life of IGF-1 has for many years been accepted as being 20 hours while in fact, it is only 8 minutes.
The extended half-life is based upon its prolonged survival in the blood when attached to the carrier protein IGFBP-3. Therefore,
like measurement of GH, IGF-1's short half-life make its random testing unreliable.
IGF Binding Protein-3: This protein is responsible for binding to IGF-1 thereby extending its half-life from 8 minutes
to 20 hours. Free or unbound BP-3 has a half-life of 20 hours. This makes BP-3 an ideal inferential marker
for growth hormone since (so far) only GH, Estradiol and Quercitin increase the production of IGFBP-3 from the liver.
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Initial Testing |
Results |
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IGF-1 |
Less than 150ng/ml |
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IGFBP-3 |
Less than 3000ng/ml |
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Urine Growth Hormone |
Less than 500 ug/g Creatine |
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DHEA-s |
Median for gender at 25-25 y/o
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Free Testosterone |
Median for gender at 25-25 y/o
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Dihydrotestosterone |
Median for gender at 25-25 y/o
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Estradiol (E2) |
Median for gender at 25-25 y/o
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Pregnenolone |
Median for gender at 25-25 y/o
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Follow-up Testing |
Results |
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IGF-1 |
Less than 150ng/ml |
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IGFBP-3 |
Less than 3000ng/ml |
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Urine Growth Hormone |
Less than 500 ug/g Creatine |
Ideally, all three of these tests need to be low in order
to support a diagnosis of Adult Growth Hormone Deficiency. Due to Secretropin's ability
to increase GH/IGF-1 and BP-3, we recommend an initial three month trial in any patient that is non-medically challenged
before deciding on injectable Growth Hormone. As always, the final decision will be between the physician and the patient.
(c) 2008 Millennium Health Centers, Inc.