Regional Fat Distribution by Dual-Energy X-Ray Absorptiometry: Comparison with Anthropometry and Application in a Clinical Trial of Growth Hormone and Exercise

1. The purpose of this study was to determine the suitability of ratios derived from dual-energy X-ray absorptiometry (DXA) whole body scans to assess regional fat distribution in older men and women by comparing them with the waist-to-hip ratio (WHR) and to evaluate their clinical utility by applying them in a clinical trial involving resistance exercise and recombinant human growth hormone. 2. Sixty-four healthy older adults (39 women and 25 men), aged 65–82 years, served as subjects. The ratios of trunk fat-to-total fat, trunk fat-to-body weight, trunk fat-to-limb fat and trunk fat % were determined by DXA. WHR was assessed on the same day, as was the ratio of subscapular/triceps skinfolds in men. Cardiovascular disease risk factors, functional capacity and serum lipids were also assessed. 3. A moderate relationship (r = 0.36-0.54) between the WHR- and DXA-derived ratios were observed for both men and women. Both DXA and WHR showed similar associations with cardiovascular disease risk factors. However, in men, all DXA ratios were able to detect subtle changes in regional fat distribution resulting from daily administration of recombinant human growth hormone in conjunction with resistance exercise for 10 weeks, whereas the WHR or subscapular/triceps ratios did not. 4. This suggests that DXA-derived ratios may be more sensitive than conventional anthropometric methods in the assessment and categorization of body fat distribution.

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Effects of Recombinant Human Growth Hormone on Hepatic Lipid and Carbohydrate Metabolism in HIV-Infected Patients with Fat Accumulation

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.87.2.8391 ◽

2002 ◽

Vol 87 (2) ◽

pp. 942-945 ◽

Cited By ~ 41

Author(s):

Jean-Marc Schwarz ◽

Kathleen Mulligan ◽

Jeongae Lee ◽

Joan C. Lo ◽

Michael Wen ◽

...

Keyword(s):

Growth Hormone ◽

Lipid Profile ◽

Human Growth Hormone ◽

Disease Risk ◽

Recombinant Human Growth Hormone ◽

Cardiovascular Disease Risk ◽

Human Growth ◽

Metabolic Effects ◽

Gh Treatment ◽

Fat Accumulation

We recently reported that treatment with a pharmacologic dose of recombinant human growth hormone (GH) resulted in a significant loss of body fat and gain in lean tissue in HIV-infected patients with syndromes of fat accumulation. However, insulin-mediated glucose disposal decreased transiently after one month of GH therapy. The present paper focuses on the changes of hepatic carbohydrate and fat metabolism associated with GH treatment in the same subjects. We assessed hepatic insulin sensitivity under both fasting and hyperinsulinemic-euglycemic clamp conditions prior to and after one and six months of GH treatment (3 mg/day) in five patients using stable isotope tracer techniques. Indirect calorimetry, and measurements of lipid concentrations. Fasting endogenous glucose production (EGP) increased significantly at one month (12.0 ± 0.7 to 14.9 ± 0.9 μmol/kg/min, P < 0.03), and the increase was sustained at six months of GH treatment (14.0 ± 1.1μ mol/kg/min, NS). This increase in EGP was driven in part by increased glucogenesis (GNG) (3.5 ± 0.9 to 5.2 ± 0.9 and 5.8 ±1.2 μmol/kg/min, n = 4, P < 0.01 and P < 0.01 at one and six months, respectively); small changes in hepatic glycogenolysis also contributed. Sustained increases in lipolysis and progressive decreases in hepatic fractional de novo lipogenesis (DNL) and triglyceride concentrations occurred with GH treatment. These changes were accompanied by an improved lipid profile with a significant increase in HDL cholesterol and significant decreases in total and LDL cholesterol and triglyceride levels, the latter consistent with the decrease in hepatic DNL. During a hyperinsulinemic-euglycemic glucose clamp, EGP and GNG were markedly suppressed compared to the corresponding time points under fasting conditions, albeit less so when measured after one month of GH treatment. Thus, in HIV-infected patients with abnormal fat distribution, pharmacologic doses of GH improved the overall lipid profile, but worsened glucose homeostasis under both fasting and hyperinsulinemic conditions. The combined implications of these positive and negative metabolic effects for cardiovascular disease risk remain unknown.

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