Diuretic induced hyponatremia in hypertensive patients

Diuretics are the recommended antihypertensive by several international guidelines. This study was designed to determine the association of hyponatremia in hypertensive patients on diuretic therapy. This was a case control study conducted at the Aga Khan University Hospital, Karachi in adult inpatients (> 18 years) who were known hypertensive. Cases were defined as hypertensives with hyponatremia and controls were defined as hypertensives without hyponatremia. Outcome was hyponatremia. Exposed were those using diuretics. Out of 1800 hypertensive patients sampled by the ICD-9-Coding; 1191 (66%) fulfilled the inclusion criteria. Cases n (%) were 553 (46.4) and controls were 638 (53.5). Among 553 cases (%) 180 (32.5) were exposed (on diuretics) and in controls 189 (29.6) were exposed (on diuretics) p=0.15. The association of hyponatremia with diuretic use was not significant with OR=1.11 (95% CI=0.86 - 1.45, p=0.40), after adjusting for chronic kidney disease, ischemic heart disease and chronic liver disease, in the final model. Diuretics were not associated with hyponatremia in hypertensive adult patients in this study.