Effect of Haemodialysis on Serum Magnesium Level in Patients with Chronic Renal Failure: A Cross-sectional Study

Abstract

Introduction: The dialysate Magnesium (Mg) concentration is the primary determinant of serum Mg levels in individuals on maintenance haemodialysis. A stable dialysate Mg content of 0.5 mmol/L is currently recommended. An alteration in this concentration can lead to altered serum magnesium levels. Few studies indicate that dialysate Mg concentration needs to be altered for maintenance of stable serum magnesium level. Aim: To compare pre and postdialysis serum magnesium levels in patients with chronic renal failure and the effect of drug intake and duration of dialysis on serum magnesium levels. Materials and Methods: This prospective observational cross- sectional study was conducted in a tertiary care hospital of Coimbatore, Tamil Nadu, India, for a period of three months, from June 2021 to August 2021. The predialysis and postdialysis serum magnesium levels of 100 chronic renal failure patients undergoing maintenance haemodialysis were measured. Parameters such as dialysis period, predialysis weight, predialysis routine blood chemistry variables (estimated glomerular filtration rate, serum urea, serum creatinine, serum sodium, serum potassium and serum calcium, serum phosphate measurements) history of diabetes, history of hypertension and history of medications, were assessed for all the patients. Statistical analysis of the data were done using Analysis Of Variance (ANOVA), Students’ t-test and Pearson’s correlation coefficient. Results: Total 71% of the study population were males and 29% were females. The mean age of the study population was found to be 51.34 years. The mean predialysis serum magnesium levels was 2.28±0.48 mg/dL. The mean postdialysis serum magnesium level was 1.69±0.52 mg/dL. Total 2% of the chronic renal failure patients had hypomagnesemia before dialysis, while 27% of the patients developed hypomagnesemia after dialysis. There was significant difference between pre and postdialysis Mg levels, p<0.001. There was no significant correlation between pre and postdialysis magnesium levels and drug intake. Patients undergoing dialysis for more than 300 days had a significantly decreased serum magnesium levels than those undergoing dialysis for less than 90 days. Conclusion: The risk of hypomagnesemia is definite in patients undergoing dialysis. Uniformity of dialysis fluids for all patients may not be advisable. Dialysate should be titrated in individual patients according to the predialysis serum magnesium levels.