Diabetes significantly weakens the immune system, making individuals more vulnerable to tuberculosis (TB) and complicating their recovery, according to health experts.
The interplay between TB and diabetes represents a major public health concern globally, and especially in India, which bears the world’s highest TB burden: 2.8 million cases and an estimated 315,000 related deaths, accounting for over a quarter of the global TB toll in 2024. At the same time, India is home to over 100 million people living with diabetes—an ever-rising number.
Experts highlight that diabetes compromises the immune system, increasing susceptibility to TB. For people already suffering from TB, diabetes further deteriorates immune defenses, disrupts blood sugar control, and raises the risk of unsuccessful treatment or even death. Hemant D. Shewade, a senior scientist at ICMR-National Institute of Epidemiology, notes that TB patients with diabetes are two to three times more likely to remain culture-positive, four times more likely to relapse after completing treatment, and five times more likely to die compared to non-diabetic TB patients, according to recent research published in PLOS One.
Managing TB becomes more challenging when diabetes is present, as TB medications can affect glucose control and overall disease management. Shewade stresses the need for better monitoring and recording of blood sugar levels in TB patients with diabetes, as well as more research into the benefits of intensive versus moderate glycemic control and the potential routine use of insulin in these cases.
Research has shown that diabetes patients face a 3.5 to 5 times greater risk of developing TB, especially those with type 1 diabetes. These patients are not only more prone to infection, but also to high relapse rates after TB treatment and increased mortality in the event of delayed diagnosis.
A recent study from AIIMS, New Delhi, led by Dr. Urvashi Singh, examined 151 type 1 diabetes patients and found that 10.6% tested positive for pulmonary tuberculosis (PTB), particularly those with a history of prior TB. Singh emphasized the urgent need for active TB screening in diabetes patients—especially those presenting with a cough lasting more than two weeks—to enable early intervention and curb community transmission.
Overall, experts recommend close monitoring, early detection, and proper management of both diabetes and TB to reduce poor outcomes and break the deadly link between the two diseases.