Diabetes epidemic may hamper TB control in low and middle-income countries

A new study has revealed that 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, 15 percent 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 percent 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 percent (ie, 8 percent less reduction) or more by 2035.

New estimates produced for the Series [Paper 1] reveal that the top 10 countries with the highest estimated number of adult TB cases associated with diabetes are India (302 000), China (156 000), South Africa (70 000), Indonesia (48 000), Pakistan (43 000), Bangladesh (36 000), Philippines (29 000), Russia (23 000), Burma (21 000), and the Democratic Republic of Congo (19 000) [see paper 1, table 2, page 4].

Series author Dr Knut Lonnroth from the Global TB Programme at WHO in Geneva said that these findings highlight the growing impact of diabetes on TB control in regions of the world where both diseases are prevalent and TB control is being undermined by the growing number of people with diabetes, which is expected to reach an astounding 592 million worldwide by 2035.

The researchers said that people with diabetes have a three times greater risk of contracting TB than people without diabetes, are four times more likely to relapse following treatment for TB, and are at twice the risk of dying during treatment than those without diabetes. These figures suggest we need to improve care for these patients at multiple levels.

The study was published in The Lancet Diabetes and Endocrinology.