Electrolyte abnormalities in diabetes mellitus in the presence of normal serum creatinine

Aim: Diabetes mellitus is a metabolic disorder that causes disturbances in the electrolyte regulating mechanisms of our body. The purpose of the study was to determine the pattern of electrolyte imbalance in patients with diabetes mellitus and compare with healthy individuals; and to correlate the degree of electrolyte imbalance with control and duration of diabetes. Methods: This cross-sectional study was conducted over a period of 6 months. It included 90 cases with diabetes mellitus and 50 cases without diabetes mellitus. All subjects had normal serum creatinine level. Serum electrolytes (sodium, potassium, chloride and bicarbonate) were measured in each subject by automated methods. The normal levels of sodium, potassium, chloride and bicarbonate were taken as 136-146, 3.5-5, 102-109 and 22-30 mmol/L respectively. Levels above or below this reference were taken as abnormal. Control of diabetes was determined by measuring HbA1c using high-performance liquid chromatography. Result: The most common abnormalities in patients with diabetes mellitus were hypochloraemia (48.89%), low serum bicarbonate (23.33%) and hyponatraemia (11.11%), though the mean values of serum electrolytes were within the normal reference range. Serum bicarbonate level was significantly lower in the group with diabetes mellitus (p = 0.010). There were a significantly greater number of cases with hyponatraemia and hypochloraemia among cases with diabetes mellitus (p < 0.016). Serum sodium was negatively correlated with glycaemic control (r = -0.39; p <0.001) and duration of diabetes (r = -0.31; p = 0.003). Conclusion: Electrolyte abnormalities are more common in patients with diabetes mellitus even with normal serum creatinine, and this correlates with control and duration of diabetes.