Advancements in TB control threatened by diabetes

Babs Verblackt, CNS Correspondent, Belgium
Progress made in tuberculosis control is at risk of being undermined by the rapid rise of diabetes in regions where both diseases are prevalent, experts warn. Patients living with diabetes are especially vulnerable to catching the lung disease. Improved care and increased efforts to diagnose and treat both diseases are urgently needed.

Diabetes increases the risk of developing active tuberculosis (TB). Furthermore, people suffering from diabetes show a higher risk of failure of TB treatment or recurrence of the lung disease. TB infection worsens glucose control in patients with diabetes.

A recent series of studies published in the medical journal The Lancet Diabetes and Endocrinology indicates that 15% of adult TB cases worldwide are already attributable to diabetes. These diabetes-associated TB cases correspond to over 1 million cases a year, with more than 40% of them occurring in India and China alone. The enormous increase of diabetes worldwide - from a current 380 million patients to an estimated 590 million 20 years from now  - occurs mostly in regions where TB is highly prevalent.

"If we are to achieve the ambitious post-2015 global TB target to reduce TB incidence by 90% by 2035, increased efforts to diagnose and treat both TB and diabetes, especially in countries with a high burden of both diseases, will be crucial", says Dr Knut Lönnroth from the WHO Global TB Programme in Geneva, and author of the studies.

Health care systems increasingly face the challenge of this double disease burden that creates obstacles for prevention and care. "People with diabetes have a three times greater risk of contracting TB than people without diabetes; they 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", emphasizes Dr Reinout van Crevel, co-author of the studies and a Specialist in Infectious Disease at Radboud University Medical Center in Nijmegen, the Netherlands.

Both-- the process of as well as the medicines used against TB and diabetes-- seem to influence each other. "More research is urgently needed in order to understand the underlying reasons for this and to further improve the care for patients", says Van Crevel, one of the initiators of an international Tuberculosis and Diabetes Mellitus programme (TANDEM), ongoing in countries such as Peru, South-Africa, Romania and Indonesia.

According to Van Crevel: "The programme focuses first of all on patient care and policies on TB and diabetes, with questions such as: How to screen all those TB patients for diabetes and vice-versa? How do we make this equally possible in poorer countries in an easy and cost efficient way? What is the best treatment for patients who suffer from both diseases at the same time?"

The answers to these questions could help turn the tide of the double disease burden. If diabetes rates continue to rise out of control, global TB incidence would be 3% to 8% higher than the projected downward trend by 2035, according to The Lancet Diabetes and Endocrinology. Public health efforts to prevent and improve care for diabetes globally could further reduce tuberculosis cases by 15% or more by 2035 compared with the present rate of decline.

Babs Verblackt, Citizen News Service - CNS
12 September 2014