Relationship between total cholesterol level and tuberculosis risk in a nationwide longitudinal cohort

The association between the total cholesterol level and tuberculosis (TB) risk has been controversial. Our study aimed to evaluate whether total cholesterol level can predict the risk of TB. Data from 5,000,566 subjects who participated in a health screening exam in 2009 were investigated using the Korean National Health Insurance Service database (2009-2018). Cox hazard regression analyses were used to evaluate TB risk according to the quartile of total cholesterol levels. During an average of 8.2 years of follow-up, 32,078 cases of TB occurred. There was a significant inverse association between the total cholesterol level and TB risk. Compared with subjects in the highest quartile, those in the lowest quartile had a 1.35-fold increased TB risk (95% confidence interval = 1.31-1.39). The association between total cholesterol level and TB risk was more apparent in young subjects (age < 65 years), those without diabetes mellitus (DM), and those without obesity (p for interaction < 0.001 for age group, DM, and body mass index). Although there was a significant inverse association between total cholesterol level and TB risk in subjects who did not use a statin, no significant association was observed between the total cholesterol level and TB risk in subjects who used a statin. A low total cholesterol level was significantly associated with an increased risk of TB, even after adjusting for confounders, especially in patients younger than 65 years, those without DM or obesity, and those who did not use a statin.