The rapid increase in rates of type 2 diabetes* in low- and middle-income countries where tuberculosis (TB) is endemic could hamper global efforts to control and eliminate TB, according to a new three-part Series about TB and diabetes, published in The Lancet Diabetes & Endocrinology.

The Series indicates that 15% of adult TB cases worldwide are already attributable to diabetes. These diabetes-associated cases correspond to over 1 million cases a year, with more than 40% occurring in India and China alone. If diabetes rates continue to rise out of control, the present downward trajectory in global TB cases could be offset by 8% (ie, 8% less reduction) or more by 2035, warn the authors.

Diabetes increases the risk of developing active TB, and is associated with a poorer TB prognosis. Conversely, TB infection worsens glucose control in patients with diabetes. Thus, as diabetes becomes more common in TB-endemic regions, health care systems will increasingly be faced with the challenge of this double disease burden.

Diabetes is making an increasingly important contribution to the TB epidemic [Paper 1]. A 52% increase in diabetes prevalence recorded over the last 3 years in the 22 highest TB burden countries is thought to be responsible for a rise in diabetes-associated TB cases from 10% in 2010 to 15% in 2013.