DE-NOVO LIPOGENESIS PREDICTS SHORT-TERM BODY-COMPOSITION RESPONSE BY BIOELECTRICAL-IMPEDANCE ANALYSIS TO ORAL NUTRITIONAL SUPPLEMENTS IN HIV-ASSOCIATED WASTING

We studied the effects of enteral supplements on protein and energy in takes, body composition, energy expenditure, and gastrointestinal hist ology in 49 subjects with human immunodeficiency virus-associated weig ht loss (12.7 +/- 0.9% of body wt). We also determined whether a stabl e-isotope mass spectrometric measurement at baseline might predict the short-term response of fat-free mass (FFM) measured by bioelectrical impedance analysis. Thirty-nine subjects completed the study after bei ng randomly assigned to receive either a whole-protein-based (n = 22) or a peptide-based (n = 17) formula. A nonsupplemented, nonrandomly as signed group (n = 13) was followed concurrently. Both formulas were we ll tolerated. Voluntary intakes of energy and protein from nonsuppleme nt sources decreased significantly during supplementation [by 819-1638 kJ (196-382 kcal)/d and 5.6-14.4 g protein/d, respectively; P<0.01] b ut to a lesser extent than the intake from the supplement [2300-2510 k J(550-600 kcal)/d and 19-28 g protein/d, respectively], so that net in creases in intakes of protein and energy (P<0.03), as well as of sever al vitamins and trace elements were increased. Nevertheless, the mean FFM did not increase for the group as a whole, although there was cons iderable interindividual heterogeneity. Changes in FFM at 6 wk were si gnificantly inversely correlated (r = 0.65, P<0.01) with baseline synt hesis of fat (de novo hepatic lipogenesis), but not with other potenti al measures of energy intake (insulin-like growth factor 1 or its bind ing protein) or inflammation (soluble tumor necrosis factor receptors I or II). The prospective identification of FFM response by measuremen t of de novo hepatic lipogenesis supported the hypothesis that the sub set of wasting patients whose FFM is unresponsive to nutrient suppleme ntation have altered nutrient metabolism.