Energy expenditure following oral glucose load in ten uremic patients before and after three months on a ketoacid-supplemented very-low-protein diet

We have previously shown that a ketoacid-supplemented very-low-protein diet (KSVLPD), which has been proposed to slow down the rate of progression of chronic renal failure (CRF), improves tissue insulin sensitivity and decrea ses hyperinsulinemia in predialytic uremic patients. However, this diet may interfere with nutritional status. The aim of this study was to study basa l energy expenditure (EE) and EE after an oral glucose load in patients wit h CRF before and during a KSVLPD (0.3 cal (.) kg wt(-1 .) d(-1) supplemente d with aminoacid and ketoanalogs) using oral glucose loading in combination with indirect calorimetry. We also monitored body weight and analyzed body composition by dual-energy x-ray (DEXA during KSVLPD. In the third month o f KSVLPD, no significant change in total body weight was observed, but DEXA showed a decrease in lean tissue mass (LTM; 46.2 +/- 3.6 kg before v 44 +/ - 3.4 kg in the third month; P <.01) and an increase in body fat mass (20.1 +/- 2.4 kg before v 21.3 +/- 2.4 kg on KSVLPD; P <.05). Postabsorptive pla sma glucose level was significantly lower, and glucose oxidation and energy expenditure per LTM were significantly increased (EE, 20 +/- 0.8 cal (.) k g LTM-1 (.) min(-1) before diet v21.9 +/- 1.1 cal (.) kg LTM-1 (.) min(-1) after 3 months on KSVLPD; P <.01). Plasma glucose and serum insulin levels were significantly lower after glucose loading, and glucose oxidation incre ased. EE values were significantly higher after the oral glucose load, and cumulative EE after oral load increased from 20.7 +/- 0.7 cal (.) kg LTM-1 . min(-1) before the diet to 22.9 +/- 1.1 cal (.) kg LTM-1 min(-1) in the t hird month of KSVLPD; P <.001). Glucose oxidation was higher and cumulative glucose storage was decreased after diet (29.6 +/- 4.2 g v20.9 +/- 3.4 g o n KSVLPD; P <.01). We conclude that KSVLPD increases EE in the postabsorpti ve state and after an oral glucose load with an adaptation of lean tissue m ass in the third month of the diet. Therefore, during KSVLPD, strict monito ring of dietetic management is necessary to maintain energy requirements at high levels appropriate to the new EE. Copyright (C) 2001 by W.B. Saunders Company.