Therapy with growth hormone for 6 months in a dose varying between 6 and 25 micrograms/kg/day increased lean body mass and decreased fat mass. The sense of general well-being improved in most patients. Furthermore, growth hormone treatment increased bone turnover without a measurable increase in bone density, caused some minor changes in lipid and carbohydrate metabolism, and increased the metabolism of thyroxine to T3.

Body composition in a group of growth hormone (GH)-deficient adults was compared with a control group matched for age, sex, body height, body weight, and body mass index by using bioelectrical impedance and deuterium oxide-dilution methods and hydrodensitometry. The body-fat percentages of GH-deficient adults were higher despite comparable weight, height, age, and body mass index. Body impedance was higher in the GH-deficient adults after correction for differences in height and fat-free mass. As a consequence, prediction formulas for body composition from body impedance developed in normal subjects cannot be applied to GH-deficient subjects. The higher body impedance in the GH-deficient subjects can be ascribed to a smaller amount of extracellular water in these subjects than in control subjects.

A B S T R A C T The formation of hemoglobin Al, was studied in intact human erythrocytes in vitro. Satisfactory methods were developed for maintaining erythrocytes under physiologic conditions for >8 d with <10% hemolysis. Hemoglobin Al, levels were determined chromatographically on erythrocyte hemolysates after removal of reversible components by incubation for 6 h at 37°C. Hemoglobin Al, concentration was found to increase linearly with time during 8 d of incubation. The rate of formation of hemoglobin Alc increased linearly as glucose concentration was increased from 40 to 1,000 mg/dl. Deoxyhemoglobin was glycosylated twice as rapidly as oxyhemoglobin.The rate of hemoglobin Al, formation was further increased by elevated 2,3-diphosphoglycerate levels, an effect that was most marked with deoxyhemoglobin. We conclude that the nonenzymatic glycosylation of hemoglobin is influenced by factors other than glucose, including oxygen tension and 2,3-diphosphoglycerate levels.

The effects of human GH administration in elderly adults with recent weight loss were investigated in a metabolic ward study. Four patients were studied for 20 days. In addition to a constant caloric and nitrogen-sufficient diet, consisting of the recommended amounts of protein and energy plus 20%, the patients received GH in dosages of 25 and 50 micrograms/kg.day for two 4-day periods (days 5-8 and 13-16, respectively). Significant increases in nitrogen retention of 1.6 (114.2) and 1.4 g/day (100 mmol/day), respectively, occurred compared with that in the control periods. No difference was found between the two GH dosages, but the nitrogen-retaining effect of the higher dose appeared to last for several days after its administration was stopped. Plasma insulin-like growth factor I levels rose during both treatment periods. No important disturbances in carbohydrate metabolism occurred. Body weight increased 2.3 kg during each treatment period, probably due to water retention. We conclude that even during more than adequate nutritional intake, low GH doses cause considerable nitrogen retention in underweight adults.

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