Health experts are warning of a looming co-epidemic of diabetes and tuberculosis that could have catastrophic consequences for health care systems around the world if not quickly addressed.
A report released today by the International Union Against Tuberculosis and Lung Disease (IUATLD) and the World Diabetes Foundation said the two diseases were already leading causes of death and disability around the world.
IUATLD senior scientific adviser Anthony Harries said in high TB-prevalence countries, diabetes increased the risk of somebody getting tuberculosis.
“It increases that risk by two or three times,” he said.
Diabetes is a non-communicable disease that is rising rapidly in developing countries, where 80 per cent of all cases are projected to occur within the next 20 years, with Asia predicted to be hit particularly hard.
The report said half of those who had diabetes would be unaware they had the disease until they developed a complication with it.
Tuberculosis is an infectious, airborne bacterial disease that lies dormant in one third of the global population.
Professor Harries said in 5 to 10 per cent of those cases, people carrying the TB bacteria would get active TB.
“What diabetes does is, through mechanisms we don’t quite understand, it also reduces the body’s immunity,” he said.
“So the immune system goes down and the body then becomes more susceptible to allowing the TB germs that are inside it, to basically multiply and get tuberculosis.
“So that’s how we think this relationship works.”
Tuberculosis-diabetes rates higher than believed
The report found that rates of combined TB and diabetes were higher and more significant than previously believed.
In the Indian state of Tamil Nadu, nearly half of all patients with TB had diabetes or pre-diabetes.
In Mexico, that rate was nearly a third, and in China 12.4 per cent of TB carriers had also been diagnosed with diabetes.
Earlier this month Australia recorded its first death of a patient with multi-drug-resistant tuberculosis.
Professor Harries said not enough was known about the relationship between diabetes and multi-drug-resistant TB.
“Intuitively, if I’m diabetic and I’m on TB treatment, two things can happen to me,” he said.
“First of all, I am more likely to fail my TB treatment because I am diabetic for various reasons.
“If I complete my TB treatment I am more likely, as a diabetic, to get tuberculosis for the second time.
“And people who fail treatment – people who get TB for the second time – are more at risk of getting drug-resistant tuberculosis.”
The report’s major recommendation is that countries begin to offer bi-directional screening where people with TB are screened for diabetes and those diagnosed with diabetes are screened for tuberculosis.