David Cohn, MD

This study highlights the well-known epidemiologic and clinical association of TB and diabetes, which has been described for decades. As early as 1859, a high frequency of TB was noted in autopsy studies of patients with diabetes. A recent review found that in  comparing patients with diabetes to those without diabetes, the relative risk for TB in cohort studies was 3.1 and in case-control studies, odds-ratios of 1.2 to 7.8.  Clinical manifestations of TB in DM are often severe (as is true for other bacterial infections and sepsis), and rates of TB failure, death and relapse are also higher in patients with DM. TB is more common in insulin-dependent diabetics, and the risk of TB increases as complications of diabetes increases. Given the increasing prevalence of diabetes in the world (estimated at 285 million cases in 2010 and to increase to 438 million cases by 2030), especially in countries with high rates of TB (China, India and subSaharan Africa), the co-epidemics of diabetes and TB present potential problems of enormous magnitude. The predicted morbidity and mortality would be analogous to the current global TB/HIV co-epidemics. In recognition of this looming situation, in 2009 the WHO, International Union Against TB and Lung Disease and World Diabetes Foundation commissioned consultations, meta-analyses and reviews, and convened a meeting of experts, resulting in recommendations in 2010 for future steps and research agenda. Four areas for high- priority research were identified: 1) better screening for TB in diabetes patients and diabetes in TB patients; 2) the impact of diabetes and non-diabetes hyperglycemia on TB treatment outcomes; 3) the implementation and evaluation of the TB-DOTS strategy for standardized case management of diabetes; and 4) the development of better point-of-care diagnostics and monitoring tests for diabetes (as is now occurring with TB). Stay tuned.