CHANGES IN BODY-COMPOSITION, RESTING ENERGY-EXPENDITURE, AND THERMAL EFFECT OF FOOD IN SHORT CHILDREN ON GROWTH-HORMONE THERAPY

The effect of growth hormone (GH) treatment on body composition, resti ng energy expenditure (REE), and the thermic effect of food (TEF) was studied in 10 prepubertal boys (aged 6.2 to 9.5 years, with subnormal spontaneous GH secretion during the first 6 months of treatment [0.2 I U/kg.d]). Patients were studied before and at 2, 4, and 6 months after commencing treatment. Height and weight increased significantly durin g treatment (112.2 +/- 4.5 to 117.2 +/- 6.0 cm and 18.0 +/- 2.8 to 20. 8 +/- 3.2 kg, respectively). Body fat percent decreased significantly (15.93% +/- 4.08% to 11.97% +/- 3.30%, P <.0002), but was not differen t at 4 and 6 months. Total body potassium (TBK) increased significantl y (39.15 +/- 5.77 to 48.70 +/- 6.35 g, P <.001) during treatment. When correcting for the expected changes in body composition over time, he ight and weight were still shown to increase, fat percent decreased si gnificantly, but TBK and mid-arm muscle circumference (MAMC) were not different from the expected values. REE increased significantly during treatment, but when it was expressed per TBK or corrected for the cha nge in kilograms of fat-free body mass (FFBM), it increased only at 2 months and stabilized thereafter. The TEF was increased at 2 and 4 mon ths of treatment and returned to pretreatment levels at 6 months of tr eatment. Substrate utilization as studied by indirect calorimetry poin ted toward a significant protein-sparing effect during the first 4 mon ths of treatment; this change tended to disappear in resting energy me tabolism by 6 months of GH treatment. In conclusion, we have shown sig nificant persistent changes in the body composition and transient chan ges in the energy metabolism of children during 6 months of GH treatme nt. Copyright (C) 1994 by W.B. Saunders Company