Benign prostatic hyperplasia (BPH) frequently leads to nocturia in aging men, significantly affecting quality of life. Previous studies showed desmopressin effectively reduces nocturnal urine production but carries the risk of hyponatremia which haven’t been fully reported. This study aimed to evaluate the incidence of hyponatremia in BPH patients using desmopressin and identify relevant risk factors.

A retrospective cohort study was conducted using the TriNetX network database, including 12,413 male BPH patients prescribed desmopressin. Hyponatremia was defined as serum sodium <135 mmol/L. Multivariate logistic regression and Kaplan-Meier analysis were performed to identify predictors and estimate long-term risk.

Hyponatremia occurred in 1,535 patients (12%) of 12,413 male. Significant predictors included younger age (Hazard Ratio [HR] = 1.93, 95% Confidence Interval [CI] 1.31-2.85), hypertensive diseases (HR=1.218, 95% CI 1.018-1.456), diabetes mellitus (HR=1.218, 95% CI 1.081-1.373), hyperlipidemia (HR=1.144, 95% CI 1-1.307), chronic kidney disease (HR=1.335, 95% CI 1.181-1.509), whereas White (HR=0.81, 95% CI 0.67-0.979) and Black races (HR=0.65, 95% CI 0.516-0.82) were protective. Kaplan-Meier analysis showed cumulative hyponatremia-free survival probabilities of 91.6% at 12 months and 88.5% at 24 months, with an overall long-term risk of hyponatremia estimated at 36.27%. Younger patients (≤74 years) exhibited increased risk of hyponatremia but was found no significant different in higher dosage group.

Hyponatremia is a significant risk in BPH patients treated with desmopressin, particularly among younger patients (≤74 years), and those with comorbidities of hypertensive diseases, diabetes mellitus, hyperlipidemia, and chronic kidney disease. Careful patient selection and routine sodium monitoring are recommended to mitigate risks.