Abstract
BACKGROUND AND OBJECTIVES: The incidence and risk of Mycobacterium tuberculosis in people with predialysis CKD has rarely been studied, although CKD prevalence is increasing in certain countries where Mycobacterium tuberculosis is endemic. We aimed to investigate the association between predialysis CKD and active Mycobacterium tuberculosis risks in a nation with moderate Mycobacterium tuberculosis risk. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this nationwide retrospective cohort study, we reviewed the National Health Insurance Database of Korea, screening 17,020,339 people who received a national health screening two or more times from 2012 to 2016. Predialysis CKD was identified with consecutive laboratory results indicative of CKD (e.g., persistent eGFR <60 ml/min per 1.73 m(2) or dipstick albuminuria). People with preexisting active Mycobacterium tuberculosis or kidney replacement therapy were excluded. A 1:1 matched control group without CKD was included with matching for age, sex, low-income status, and smoking history. The risk of incident active Mycobacterium tuberculosis, identified in the claims database, was assessed by the multivariable Cox regression model, which included both matched and unmatched variables (e.g., body mass index, diabetes, hypertension, places of residence, and other comorbidities). RESULTS: We included 408,873 people with predialysis CKD and the same number of controls. We identified 1704 patients with active Mycobacterium tuberculosis (incidence rate =137.5/100,000 person-years) in the predialysis CKD group and 1518 patients with active Mycobacterium tuberculosis (incidence rate =121.9/100,000 person-years) in the matched controls. The active Mycobacterium tuberculosis risk was significantly higher in the predialysis CKD group (adjusted hazard ratio, 1.21; 95% confidence interval, 1.13 to 1.30). The risk factors for active Mycobacterium tuberculosis among the predialysis CKD group were old age, men, current smoking, low income, underlying diabetes, chronic obstructive pulmonary disease, and Kidney Disease Improving Global Outcomes CKD stage 1 (eGFR≥90 ml/min per 1.73 m(2) with persistent albuminuria) or stage 4/5 without dialysis (eGFR<30 ml/min per 1.73 m(2)). CONCLUSIONS: In the Korean population, the incidence of active Mycobacterium tuberculosis was higher in people with versus without predialysis CKD.