Symptomatic Benign Prostate Hyperplasia May Increase the Risk of Kidney Stones

Benign prostatic hyperplasia (BPH) and kidney stones are among the most common benign urologic conditions in males. A key risk factor for kidney stones is low fluid intake. Males with BPH frequently restrict fluid intake to manage lower urinary tract symptoms, potentially increasing their stone risk. We aimed to evaluate the incidence of kidney stones in males with symptomatic BPH compared with those without BPH.

We conducted a nationwide retrospective cohort study using TriNetX, a database of deidentified electronic health records of over 118 million US patients covering a diverse patient population with respect to geographic location, racial and ethnic background, income level, and insurance type. Male patients aged 45-85 with and without symptomatic BPH were included. We excluded patients who carried a diagnosis of kidney stones before their index event as well as patients with several known risk factors for stones such as hyperparathyroidism and cystinuria. Propensity score matching (PSM) was performed based on race/ethnicity, obesity, hypertension, and type 2 diabetes. The primary outcome was a kidney stone diagnosis within 5 years of meeting the inclusion criterion, identified using ICD codes. Patients were stratified into 5-year age brackets. Cox proportional hazards models were used to calculate hazard ratios (HRs) with 95% confidence intervals.

After PSM, the final cohorts included 517,180 men with BPH and 560,006 without BPH. Across all eight 5-year age groups, BPH patients had a significantly higher incidence of kidney stones with HRs ranging from 2.21 to 2.75. The average HR for stone development in BPH patients across all ages was 2.51.

Patients with symptomatic BPH may be at a significantly higher risk of kidney stone formation. Further investigation is warranted to determine whether this relationship is because of behavioral factors, such as fluid restriction, or shared underlying pathophysiology.