INS and tuberculosis: Subpopulation analysis revealed that metformin was protective from developing TB diseases in many subgroups, including patients not using insulin (HR: 0.87 [0.78–0.97]), patients not using OHAs other than metformin (HR: 0.57 [0.46–0.71]), and patients using metformin but not insulin nor other OHAs (HR: 0.51 [0.39–0.66]), and patients not using statin (HR: 0.86 [0.77–0.96]).