Metabolic acidosis and its association with nutritional status in hemodialysis.

Introduction: Metabolic acidosis is a common problem in dialysis patients and plays an important role in the pathogenesis of protein-energy malnutrition in these patients.

Objectives: To assess the prevalence of metabolic acidosis in hemodialysis and search their association with nutritional status.

Methods: A cross-sectional study was performed in hemodialysis patients at a single center. Nutritional status was assessed by anthropometric, biochemical and multifrequency bioelectrical impedance analysis. Metabolic acidosis was defined as serum bicarbonate (BIC) < 22 mEq/L and patients were divided into 3 groups according to BIC (< 15.15 to 21.9 and ≥ 22). The association between BIC and continuous variables was investigated using the Kruskal Wallis test. The linear correlation between BIC and the variables of the study was also tested.

Results: We studied 95 patients, 59% male, mean age 52.3 years. The prevalence of metabolic acidosis was 94.7%. BMI, interdialytic weight gain and PTH were significantly different among the 3 groups of BIC. The BIC was negatively correlated with urea, phosphorus and interdialytic weight gain. There was no significant correlation with albumin, phase angle and lean body mass index.

Conclusion: The prevalence of metabolic acidosis was high in this population, and a lower BIC correlated with higher levels of urea, PTH, phosphorus, interdialytic weight gain and lower BMI. The evaluation of acid-basic status should be routinely implemented in dialysis patients by considering the negative effects of acidosis on the nutritional status, inflammation and bone disease.