Sex Differences in Electrolyte Disturbances Among Diuretic Users According to Renal Function and Age.

Introduction: Diuretics are widely used in Japan for the treatment of hypertension and heart failure. Electrolyte disturbance is a common adverse reaction to diuretics and may be life-threatening. Previous studies have shown that diuretic-induced electrolyte disturbance is more common in women. Electrolyte balance is regulated by the kidneys, and renal function tends to decline with advancing age.

Objective: The aim of this study was to identify patients at high risk of adverse reactions to diuretics, considering the effects of sex, renal function, and age on susceptibility to diuretic-induced electrolyte disturbance.

Methods: Claims data for 67,135 patients on diuretics in Japan were sourced from DeSC Healthcare, Inc. The data covered the period from April 2020 to March 2021.

Results: Analysis of patient numbers using the chi-squared test showed that hyperkalemia was more common in men than in women (326 vs. 271; p = 0.003) and that hypokalemia was more common in women than in men (413 vs. 285; p < 0.001). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for women considering age and renal function (estimated glomerular filtration rate [eGFR]). In elderly patients aged ≥ 75 years, the odds of developing hypokalemia in women compared to men were 1.47 (95% CI 1.13-1.91) for eGFR 60-30 mL/min/1.73 m² and 2.05 (95% CI 1.08-4.10) for eGFR < 30 mL/min/1.73 m².

Conclusion: Among women aged ≥ 75 years, those in lower eGFR groups (60-30 and < 30) had higher odds of hypokalemia compared to men. These data highlight the importance of monitoring for adverse reactions to diuretics, particularly hypokalemia, in elderly women with low eGFR.