American journal of kidney diseases : the official journal of the National Kidney Foundation
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Comparative Study
Metabolic acidosis in advanced renal failure: differences between diabetic and nondiabetic patients.
Metabolic acidosis is almost invariably a consequence of advanced renal failure, although its severity can vary widely. To evaluate the determinants of the severity of metabolic acidosis, with special interest in determining if there is any difference in the prevalence and severity of metabolic acidosis between patients with and without diabetes, 113 predialysis patients with renal failure were studied. Criteria for inclusion onto the study were: creatinine clearance (Ccr)/1.73 m2 less than 30 mL/min, no alkali therapy within the previous 30 days, and the absence of respiratory diseases. ⋯ By multiple logistic regression analysis, the best determinants for a serum bicarbonate level greater than 19 mmol/L were: the diagnosis of diabetic nephropathy (odds ratio, 0.107; P = 0.0002), Ccr-Cu (odds ratio, 0.824; P = 0. 014), and age (odds ratio, 0.966; P = 0.046). In conclusion, patients with diabetes with advanced renal failure showed a less severe metabolic acidosis, which cannot be explained by gastrointestinal hydrogen ion losses, drugs, or reduced protein catabolic rate. Patients with diabetes may have a more efficient extrarenal generation of bicarbonate than end-stage renal failure patients without diabetes.