The Occurrence of Nephrolithiasis in Gout Patients: A Longitudinal Follow-Up Study Using a National Health Screening Cohort.

The association of gout with nephrolithiasis has been suggested. The current study investigated the risk of nephrolithiasis in patients with gout. The relationship of nephrolithiasis with gout was assessed according to patient characteristics. Individuals in the Korean National Health Insurance Service−Health Screening Cohort were examined. The 17,043 participants with gout were paired with 68,172 comparison participants. The diagnosis of nephrolithiasis was examined in both the gout and control groups. The possible risk of nephrolithiasis in the gout group was analyzed using a stratified Cox proportional hazards model. Subcategory analyses were conducted according to demographic features and comorbidities. The rate of nephrolithiasis was 3.3% (569/17,043) in the gout group and 2.6% (1786/68,172) in the control group. The adjusted hazard ratio (aHR) of gout for nephrolithiasis was 1.23 (95% confidence intervals [95% CI] = 1.12−1.36) in the overall study population. The < 60 years and male groups showed an increased risk of nephrolithiasis related to gout (aHR = 1.26 [1.13−1.42] for the < 60 years group; aHR = 1.27 [1.15−1.41] for the male group). Regarding comorbidities, all subgroups except for the underweight, overweight, total cholesterol ≥ 240 mg/dL, fasting blood glucose ≥ 100 mg/dL, and CCI score 1 and ≥ 2 groups showed a higher risk of nephrolithiasis in gout patients. The gout patients presented an increased occurrence of nephrolithiasis. The middle-aged, male, and healthy populations showed consistently higher HRs of nephrolithiasis related to gout.