ASSOCIATION BETWEEN NUTRITIONAL STATUS AND METABOLIC ACIDOSIS AMONG PATIENTS UNDERGOING MAINTENANCE HAEMODIALYSIS

Abstract

Objective: To determine the association between body mass index (BMI) and metabolic acidosis among patients with end-stage kidney disease undergoing maintenance hemodialysis. Methods: This cross-sectional study was conducted in the Department of Nephrology, a tertiary care hospital in Lahore, Pakistan, from March 2026 to June 2026. A total of 196 adults receiving maintenance hemodialysis were enrolled by consecutive sampling. Metabolic acidosis was defined as pre-dialysis serum bicarbonate <22 mEq/L. BMI was classified according to World Health Organization criteria. Associations between BMI and metabolic acidosis were evaluated using chi-square test and multivariable logistic regression after adjustment for age, sex, diabetes mellitus, dialysis duration, serum albumin, and dialysis frequency. Results: Of 196 patients (mean age 48.9±12.9 years; 59.7% male), 129 (65.8%) had metabolic acidosis. Patients with metabolic acidosis had a significantly lower mean BMI than those without (20.53±1.94 vs. 24.85±2.67 kg/m², p<0.001). Metabolic acidosis was most prevalent among underweight (79.5%) and normal-weight (75.6%) patients and least frequent among overweight/obese patients (44.8%). After adjustment for potential confounders, underweight (adjusted OR 4.10, 95% CI 1.55–10.86) and normal BMI (adjusted OR 3.21, 95% CI 1.55–6.66) remained independently associated with metabolic acidosis. Conclusion: Lower BMI is independently associated with metabolic acidosis in patients with end-stage kidney disease receiving maintenance hemodialysis. Routine nutritional assessment together with serum bicarbonate monitoring may help identify patients at increased risk.