New research aims to estimate the benefits of different ways to carry out screening both patients with tuberculosis (TB) for diabetes and the other way around in parts of the world where both diseases are common.
Those who live in urban areas and on low incomes in less well-off countries are especially at risk of developing TB.
People already suffering from diabetes face about three times the risk of also acquiring TB, a potentially fatal disease. More than half of people with diabetes in the world are thought not to be aware of their condition.
Researchers at St George's, University of London, hope the study will lead to better estimates of how rising diabetes prevalence might be increasing the number of people with tuberculosis disease.
Julia Critchley, Professor of Epidemiology at St George's, University of London, said: "We urgently need to work out the impact on the world's population of this link and the likely benefits of different interventions to break this potential health catastrophe.
"People with diabetes have greater risk of developing active TB and may face worse results after treatment. Some studies suggest they are more likely to die from TB. They may also be more infectious and transmit more TB to other people who do not have diabetes.
"The interaction of these different effects is unclear. So this research really is a global first and is vital."
They will study results of field work currently being carried out across the world, to estimate the effect of diabetes on tuberculosis in different countries and the likely benefits of different ways of screening and treating people with these diseases.
In the UK, about 2.9 million people are affected by diabetes, a condition where the body either does not produce enough insulin to function properly or produces no insulin at all.
According to the World Health Organisation, 382 million people worldwide had diabetes in 2013 and diabetes resulted in 1.4 million deaths worldwide in 2011; 80% of them live in low and middle income countries where tuberculosis is common. The International Diabetes Federation predicts that 592 million people worldwide will have diabetes in 2035.
The researchers at St George's will be working with colleagues based at the Weill Cornell Medical College in Qatar.