Risk of active tuberculosis among people with diabetes mellitus: systematic review and meta-analysis.

OBJECTIVE: To assess the risk of active TB in people with DM and the factors associated with this risk. METHODS: Systematic review and meta-analysis. We searched the literature for studies that reported the effect of DM on TB controlled for the effect of age. Studies that had not established the diagnosis of DM prior to detecting active TB were excluded. Study quality was assessed by Newcastle-Ottawa scale and we conducted a meta-analysis using random-effects models. RESULTS: Of 14 studies (eight cohort and six case-control studies) that involved 22 616 623 participants met the selection criteria and were included in the analysis. There was substantial variation between studies in the estimates of the effect of DM on TB. However, the pooled estimates from seven high-quality studies showed that diabetic people have a 1.5-fold increased risk of developing active TB vs. those without DM (95%CI 1.28-1.76), with relatively small heterogeneity (I2  = 44%). The increased risk of TB was observed predominantly among DM populations with poor glycaemic control. CONCLUSION: There is evidence suggesting an increased risk of developing TB among people with DM, and that improving glycaemic control in DM patients would reduce the risk of developing TB. An integrated approach is needed to control the dual burden of DM and TB.