AntiagingAtlanta

Murray RD - J Clin Endocrinol Metab - 01-APR-2004; 89(4): 1586-91
From NIH/NLM MEDLINE
NLM Citation ID:
15070916 (PubMed)
Full Source Title:
Journal of Clinical Endocrinology and Metabolism
Publication Type:
Journal Article
Language:
English
Author Affiliation:
Department of Endocrinology, Christie Hospital, Manchester M20 4BX, United Kingdom.
Authors:
Murray RD; Adams JE; Shalet SM
Abstract:
The current biochemical definition of severe HGH deficiency (stimulated peak GH < 3 micro g/liter) provides good separation of HGH-deficient (GHD) adults from normal subjects, although it may not account for all patients with impaired GH secretion. The vast majority of normal subjects display a peak HGH level in excess of 7 micro g/liter in response to the insulin tolerance test. Using a peak HGH response of 7 micro g/liter as an arbitrary upper limit, we investigated the effects of partial HGH deficiency (HGH insufficiency, HGHI; peak GH response of 3-7 micro g/liter) on the body composition of hypopituitary adults. HGHD adults (n = 30, peak GH < 3 micro g/liter) were of shorter stature than the controls. Body mass index was not significantly increased, but waist/hip ratio (0.885 vs. 0.818, P = 0.001) and skinfold thickness (78.2 vs. 59.6 mm, P = 0.003) were greater than control subjects. Bioimpedance analysis revealed these patients to have reduced lean body mass (LBM) (44.4 vs. 51.2 kg, P = 0.023) and increased fat mass (FM) (25.7 vs. 18.4 kg, P = 0.039). Dual-energy x-ray absorptiometry (DXA) analysis of body composition confirmed reduced LBM (43.6 vs. 50.6 kg, P = 0.010) and increased FM (26.0 vs. 19.2 kg, P = 0.015). The excess FM was observed to be primarily truncal in distribution. Similarly, GHI adults were of shorter stature but with increased waist/hip ratio (0.871 vs. 0.818, P = 0.006) and skinfold thickness (80.8 vs. 59.6 mm, P = 0.003), compared with controls. Bioimpedance analysis revealed a reduction in LBM (44.9 vs. 51.2 kg, P = 0.020). DXA studies confirmed the reduced LBM (45.0 vs. 50.6 kg, P = 0.041) and additionally noted an increase in percent FM (32.9 vs. 27.4%, P = 0.019). All measures of body composition in the HGHI patients were intermediate between those of the controls and HGHD patients. Serum leptin levels were significantly elevated in both the HGHD (41.5 vs. 20.7 ng/ml, P = 0.009) and GHI (36.7 vs. 20.7 ng/ml, P = 0.022) adults, compared with healthy controls. The excess FM observed using DXA in the HGHD and HGHI adults equated to 6.5 kg (8%) and 3.5 kg (5.5%), respectively, relative to healthy controls. In summary, we have shown that adults with GHI have abnormalities of body composition characteristic of HGHD. The degree of abnormality of body composition lies between that of healthy subjects and HGHD adults and correlates with the IGF-I level. Any future trials of HGH replacement in patients with HGHI must await further studies to establish the exact impact of this relative deficiency on the broad spectrum of biological end points influenced by HGH status.
Major Subjects:

• Body Composition
• Human Growth Hormone / * deficiency
• Hypopituitarism / * complications

Additional Subjects:

• Adult
• Anthropometry
• Cohort Studies
• Densitometry, X-Ray
• Electric Impedance
• Humans
• Insulin-Like Growth Factor I / metabolism
• Leptin / blood
• Metabolism, Inborn Errors / complications / metabolism / pathology
• Research Support, Non-U.S. Gov't
• Skinfold Thickness

Chemical Compound Name:
(Leptin); 12629-01-5(Human Growth Hormone); 67763-96-6(Insulin-Like Growth Factor I)