How diabetes worsens TB, causes treatment failure and death

August 5, 2025

New Delhi: Diabetes continues to severely weaken the immune system, increasing both the risk and severity of tuberculosis (TB), according to health experts who warned on Tuesday of the growing dual burden in India. This intersection of two major health challenges – diabetes and TB – is placing immense pressure on individuals, communities, and healthcare systems.

India Faces the Highest TB Burden Worldwide

India continues to carry the world’s highest TB burden, with 28 lakh cases in 2024, accounting for 26% of the global caseload. The country also reported 3.15 lakh TB-related deaths, representing 29% of global TB mortality. Simultaneously, diabetes cases have surged, with over 100 million Indians currently living with the disease.

Diabetes Worsens TB Outcomes, Increases Mortality

“Diabetes weakens the immune system, worsening TB outcomes. It also impairs blood sugar control, increases the risk of treatment failure, and raises the likelihood of death during TB treatment,” said Dr. Hemant D. Shewade, senior medical scientist at ICMR-National Institute of Epidemiology, Chennai.
A recent PLOS One study led by Shewade found that individuals with both conditions are:

• 2–3 times more likely to remain culture-positive

• 4 times more likely to relapse

• 5 times more likely to die compared to TB patients without diabetes.

TB treatment further complicates glucose management, hindering effective diabetes control.

Need for Tailored Diabetes Management in TB Patients

Dr. Shewade emphasized that current TB programme guidelines treat diabetes patients uniformly, whether or not they have TB. He stressed the urgent need for better glycemic monitoring and tailored treatment protocols.
He also called for more evidence on optimal HbA1c targets and whether insulin therapy should be universally applied to TB-diabetes cases. The study recommended using capillary fasting blood glucose (cFBG) to monitor diabetic status in these patients.

Type 1 Diabetes Patients at Higher Risk of Pulmonary TB

Dr. Urvashi Singh from AIIMS, New Delhi, cited recent research in Multidisciplinary Respiratory Medicine that studied 151 type 1 diabetes patients. About 10.6% showed sputum culture positivity for pulmonary TB, particularly those with a prior TB history.
She stressed the need for routine TB screening among type 1 diabetics to enable early detection and prevent community transmission.