Mumbai: After confronting multidrug-resistant tuberculosis (TB), India is heading towards a more serious health threat and medical crisis—diabetes-associated TB. The country has the highest number of diabetes-linked TB cases, which hamper global efforts to control and eliminate TB, according to a new study commissioned by The Lancet.

“Diabetes is making an increasingly important contribution to the TB epidemic and 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," says the study to be published in the medical journal this week. New estimates for a three-part TheLancet series reveal that the top 10 countries with the highest estimated number of adult TB cases associated with diabetes are India (302,000 cases), China (156,000), South Africa (70,000), Indonesia (48,000), Pakistan (43,000), Bangladesh (36,000), the Philippines (29,000), Russia (23,000), Myanmar (21,000), and the Democratic Republic of Congo (19,000). India has the second largest population of diabetes patients in the world with 30 million people diagnosed with the disease—next only to China. The country also has the highest burden of TB in the world, with an estimated two million new cases surfacing annually.

A rapid increase in the incidence of Type 2 diabetes in low- and middle-income countries where tuberculosis (TB) is endemic could hamper global efforts to control and eliminate TB. Type-2, or non-insulin-dependent diabetes, is the most common form of the disease.

The Lancet study indicates that 15% of adult TB cases worldwide are already attributable to diabetes. Diabetes-associated cases number upwards of one million a year, with more than 40% reported 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% (i.e, 8% less reduction) or more by 2035, the study warned.

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 a double disease burden, the study points out. “These findings highlight the growing impact of diabetes on TB control in regions of the world where both diseases are prevalent," says Knut Lönnroth at the Global TB Programme at the World Health Organization in Geneva, and the key author of the series.

“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," he said in The Lancet note.

This double disease burden creates obstacles for the prevention and care of both diseases, he says.

According to co-author Reinout van Crevel, “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."

An editorial accompanying TheLancet series warns that, as papers from the series clearly show, continued progress in reducing communicable diseases like TB cannot be made without adequate provision of resources to combat diabetes.

“This knowledge should be a wake-up call to the global community and local providers to invest further in the prevention and treatment of chronic diseases like obesity and diabetes, which continue to be relatively ignored when it comes to health care funding," it says.