1. Department of Otorhinolaryngology-Head & Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Korea
2. Department of Otorhinolaryngology-Head & Neck Surgery, Hanyang University College of Medicine, Seoul, Korea
3. Department of Urology, Hallym University College of Medicine, Anyang, Korea
4. Department of Neurology, Hallym University Sacred Heart Hospital, Anyang, Korea
5. Department of Otorhinolaryngology-Head & Neck Surgery, Hallym University College of Medicine, Anyang, Korea
6. Hallym Data Science Laboratory, Hallym University College of Medicine, Anyang, Republic of Korea
*So Young Kim and Chang Myeon Song are equally contributed in this study
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.
Keywords: nephrolithiasis, kidney calculi, stroke, infarct, cohort studies, nested case-control studies.