Nephrolithiasis predicts ischemic stroke: A longitudinal follow-up study using a national sample cohort
Abstract
This study sought to evaluate associations between nephrolithiasis and hemorrhagic and ischemic
stroke using a national sample cohort from Korea. Data from 2002 to 2013 were collected for
individuals ≥ 20 years of age in the Korean National Health Insurance Service (NHIS)-National
Sample Cohort. We extracted nephrolithiasis patients (n = 22,636) and 1:4 matched controls (n =
90,544) and analyzed the occurrence of stroke. Matching was performed based on age, sex, income,
region of residence, hypertension, diabetes mellitus, and dyslipidemia history. Crude and adjusted
hazard ratios (HRs) were calculated using Cox proportional hazard models, and 95% confidence
intervals (CIs) were determined. We performed subgroup analyses according to age, sex, and
follow-up period. The adjusted HR of ischemic stroke was 1.13 (95% CI = 1.06-1.21) in the
nephrolithiasis group (P < 0.001). The relationship between nephrolithiasis and ischemic stroke
remained present for the young women and middle-aged men as well as during a follow-up period of
≤ 1 year. The HR for hemorrhagic stroke did not reach statistical significance. The risk of ischemic
stroke was higher in the nephrolithiasis patients.