Abstract
One of the crucial risk factors for tuberculosis (TB) is diabetes mellitus (DM), and physical activity could afford protective effects for the former disease entity. We aimed to evaluate the association between physical activity (intensity and amount) and TB development in individuals with type 2 DM (T2DM) among the South Korean nationwide cohort. Using the Korean National Health Information Database, we screened individuals who underwent the national health examination between 2009 and 2012 and identified 2,437,443 eligible individuals with T2DM. They were followed up to the date of TB notification, death, censor, or until December 2018. We identified 21,275 individuals with newly developed TB (active TB, either pulmonary or extrapulmonary). Physical activity was evaluated according to the health examination questionnaire, categorized them by activity intensity (walking, moderate, and vigorous) and amount measured by metabolic equivalent task minutes per week (METs-min/week). To estimate the adjusted hazard ratio (aHR) of risk factors for TB, we used the multivariate Cox proportional hazard models. The risk of developing TB declined with increasing activity intensity. Individuals with vigorous activity had the lowest risk for TB (aHR 0.85, 95% confidence interval [CI] 0.82-0.89) compared with individuals without vigorous activity. The risk of TB development decreased with increasing amount of activity. Individuals ≥ 1,500 METs-min/week had the lowest risk for TB (incidence rate 1.22/1000 person-years, aHR 0.84, 95% CI 0.80-0.88) compared with individuals < 500 METs-min/week. Physical activity intensity and amount were inversely correlated with TB risk in individuals with T2DM.