Resting energy expenditure in pre-dialysis diabetic patients

Background. The metabolic derangements of diabetes mellitus (DM) associated with those of chronic renal failure (CRF) may interfere with the energy an d protein balance of patients with both diseases. The aim of this study was to verify whether the resting energy expenditure (REE) of non-dialysis chr onic renal failure diabetic patients differs from that of chronic renal fai lure patients without DM. Methods. REE was measured by indirect calorimetry in 24 CRF diabetic patien ts (CRF diabetes group), matched for age, gender, and degree of renal impai rment to 24 CRF patients without DM (CRF control group). Results. The CRF diabetes group had a significantly higher REE (1538 +/- 23 0 kcal/day) than the CRF control group (1339 +/- 315 kcal/day, P=0.009). Th is difference was maintained even when the REE was adjusted for lean body m ass (LBM; 30.3 +/- 4.3 vs 26.3 +/- 5.4 kcal/kg LBM/day, P=0.004). Mean prot ein intake was significantly higher in the CRF diabetes than in the CRF con trol group (0.89 +/- 9.20 vs 0.76 +/- 0.25 g/kg/day, P=0.02). Mean protein equivalent of nitrogen appearance (PNA) was also significantly higher in th e CRF diabetes patients (1.21 +/- 0.31 vs 1.03 +/-0.22 g/kg/day, P=0.02), r eflecting a higher protein intake and/or elevated protein breakdown. Accord ingly, REE was directly correlated with PNA mainly in the CRF diabetes grou p (r = 0.57, P < 0.003). Conclusion. Metabolic disturbances of poorly controlled DM may account for the higher REE observed in the CRF diabetes group. The role of the apparent ly higher protein breakdown in this increased REE remains to be clarified.