LOW-PROTEIN DIET IN UREMIA - EFFECTS ON GLUCOSE-METABOLISM AND ENERGY-PRODUCTION RATE

Low-protein diets (LPD) increase insulin-mediated glucose disposal in chronic renal failure (CRF), but the fate of the better utilized gluco se and the effect on energy production rate are unknown. Using a two-s tep (1 and 5 mU . kg(-1). min(-1)) euglycemic hyperinsulinemic clamp c ombined with indirect calorimetry, we studied the effects of a LPD (0. 3 g . kg(-1). day(-1), supplemented with essential amino acids and ket oanalogs) in six patients suffering from chronic renal failure. After three months of diet, no significant change was observed concerning gl omerular filtration rate, body wt, or arterial pH. In the postabsorpti ve state, plasma glucose and insulin levels were significantly lower, and energy production rose from 15.72 +/- 0.48 to 17.16 +/- 0.67 Cal . kg(-1). min(-1) (P < 0.05). Insulin-stimulated glucose oxidation (2.3 6 +/- 0.29 vs. 3.37 +/- 0.35 mg . kg(-1). min(-1); P < 0.05 at first c lamp step) and nonoxidative disposal (P < 0.05 at both clamp steps) in creased after LPD. This confirms that LPD ameliorates insulin sensitiv ity in CRF, even for low plasma insulin concentrations. Since energy p roduction rate is increased by LPD, the caloric intake should be incre ased when protein intake is restricted.