No abstract

Leptin is a protein encoded by the ob gene that is expressed in adipocytes and regulates eating behavior via central neuroendocrine mechanisms. Serum leptin levels have been shown to correlate with weight and percent body fat in normal and obese individuals; however, it is not known whether the regulation of leptin is normal below a critical threshold of body fat in chronic undernutrition. We investigated serum leptin levels in 22 women, aged 23 +/- 4 yr, with anorexia nervosa. Duration of disease, weight, BMI, percent body fat, and serum leptin levels were determined for each patient. Nutritional status was assessed further by caloric intake and measurement of insulin and insulin-like growth factor I (IGF-I) levels. Twenty-three healthy women, aged 23 +/- 4 yr, taking no medications, with normal menstrual function and body mass index (BMI) between 20-26 kg/m2 (mean, 23.7 +/- 1.7 kg/m2), served as a control population for comparison of leptin levels. Subjects with anorexia nervosa were low weight (BMI, 16.3 +/- 1.6 kg/m2; normal, 20-26 kg/m2) and exhibited a striking reduction in percent body fat (7 +/- 2%; normal, 20-30%). The mean serum leptin level was significantly decreased in subjects with anorexia nervosa compared with that in age- and sex-matched controls of normal body weight (5.6 +/- 3.7 vs. 19.1 +/- 8.1 ng/mL; P < 0.0001). Serum leptin levels were correlated highly with weight, as expressed either BMI (r = 0.66; P = 0.002) or percent ideal body weight (r = 0.68; P = 0.0005), body fat (r = 0.70; P = 0.0003), and IGF-I (r = 0.64; P = 0.001), but not with caloric intake or serum levels of estradiol or insulin in subjects with anorexia nervosa. The correlation between leptin and body fat was linear, with progressively lower, but detectable, leptin levels measured even in patients with less than 5% body fat, but was not significant when the effects of weight were taken into account. In contrast, the correlation between leptin and IGF-I remained significant when the effects of weight, body fat, and caloric intake were taken into account. In normal controls, leptin correlated with BMI (r = 0.55; P = 0.007) and IGF-I (r = 0.44; P < 0.05), but not with fat mass. These data demonstrate that serum leptin levels are reduced in association with low weight and percent body fat in subjects with anorexia nervosa compared to normal controls. Leptin levels correlate highly with weight, percent body fat, and IGF-I in subjects with anorexia nervosa, suggesting that the physiological regulation of leptin is maintained in relation to nutritional status even at an extreme of low weight and body fat.

Acquired hypogonadism is being increasingly recognized in adult men. However, the effects of long term testosterone replacement on bone density and body composition are largely unknown. We investigated 36 adult men with acquired hypogonadism (age, 22-69 yr; median, 58 yr), including 29 men with central hypogonadism and 7 men with primary hypogonadism, and 44 age-matched eugonadal controls. Baseline evaluation included body composition analysis by bioimpedance, determination of site-specific adipose area by dual energy quantitative computed tomography scan (QCT) of the lumbar spine, and measurements of spinal bone mineral density (BMD) using dual energy x-ray absortiometry, spinal trabecular BMD with QCT, and radial BMD with single photon absorptiometry. Percent body fat was significantly greater in the hypogonadal men compared to eugonadal men (mean +/- SEM, 26.4 +/- 1.1% vs. 19.2 +/- 0.8%; P < 0.01). The mean trabecular BMD determined by QCT for the hypogonadal men was 115 +/- 6 mg K2HPO4/cc. Spinal BMD was significantly lower than that in eugonadal controls (1.006 +/- 0.024 vs. 1.109 +/- 0.028 g/cm2; P = 0.02, respectively). Radial BMD was similar in both groups. Testosterone enanthate therapy was initiated in 29 hypogonadal men at a dose of 100 mg/week, and the subjects were evaluated at 6-month intervals for 18 months. During testosterone therapy, the percent body fat decreased 14 +/- 4% (P < 0.001). There was a 13 +/- 4% decrease in subcutaneous fat (P < 0.01) and a 7 +/- 2% increase in lean muscle mass (P = 0.01) during testosterone therapy. Spinal BMD and trabecular BMD increased by 5 +/- 1% (P < 0.001) and 14 +/- 3% (P < 0.001), respectively. Radial BMD did not change. Serum bone-specific alkaline phosphatase and urinary deoxypyridinoline excretion, markers of bone formation and resorption, respectively, decreased significantly over the 18 months (P = 0.003 and P = 0.04, respectively). We conclude that testosterone therapy given to adult men with acquired hypogonadism decreases sc fat and increases lean muscle mass. In addition, testosterone therapy reduces bone remodeling and increases trabecular bone density. The beneficial effects of androgen administration on body composition and bone density may provide additional indications for testosterone therapy in hypogonadal men.

Despite outpatient follow-up, community-dwelling girls with AN continue to have lower fat and higher fiber intakes than do healthy adolescents, which results in lower calorie intakes. Nutritionally related hormones are associated with specific nutrient intakes.

No abstract

These data demonstrate that intensive lifestyle modification significantly improved important cardiovascular risk indices in HIV-infected patients with the metabolic syndrome. Lifestyle modification may be a useful strategy to decrease cardiovascular risk in this population.

To determine whether a therapeutic dose of docosahexaenoic acid (DHA), an-3 fatty acid, will slow the course of retinal degeneration in adult patients with retinitis pigmentosa who are also receiving vitamin A. Design: Randomized, controlled, double-masked trial of 221 patients, aged 18 to 55 years, evaluated over a 4-year interval. Patients were given either 1200 mg/d of docosahexaenoic acid or control capsules. All were given 15000 IU/d of vitamin A (given as retinyl palmitate). Randomization considered genetic type and baseline dietary-3 fatty acid intake. Main Outcome Measures: The primary outcome measure was the total point score for the 30-2 program of the Humphrey field analyzer; secondary outcome measures were the total point score for the 30-2 and 30/60-1 programs combined, 30-Hz electroretinogram amplitude, and Early Treatment Diabetic Rentinopathy Study visual acuity. Results: No significant differences in decline in ocular function were found between the docosahexaenoic

Physiologic testosterone administration increases lean body mass and improves quality of life among androgen-deficient men with the AIDS wasting syndrome.