People with diabetes up to 2-3 times higher risk of TB

[To listen to audio podcast of CNS Exclusive interview with Dr Anil Kapur on TB-diabetes, click here]
People with diabetes are at a high risk of tuberculosis (TB). "There are several studies that have been done, there are systematic reviews that have been done which indicates that people with diabetes might have 2 to 3 times higher risk of getting TB" said Dr Anil Kapur, President of the World Diabetes Foundation (WDF). "Not only that, patients with TB and associated diabetes, have increased mortality. The risk of mortality is much higher in TB patients who have co-existing diabetes. There are also evidences to suggest that when there is co-existing diabetes it takes longer for the sputum to become negative (for TB) with anti-tubercular treatment" said Dr Anil Kapur. Read more

"There are also suggestions that there are interactions between drugs that are used for treating tuberculosis and managing diabetes, which would affect both the treatment of TB and diabetes. Also there is an issue that because of TB, people who are at risk of diabetes and are not at this stage dealing with diabetes (although they may be having pre-diabetes), so when there is a serious infection like TB, this temporarily leads to a phase where blood sugar levels are up, of course blood sugar levels come down when TB is brought under control. But none-the-less these people (with TB) remain at high risk of getting diabetes in the future" further explained Dr Anil Kapur.

According to a research study done by the University of Texas School of Public Health Brownsville Regional Campus, people with type-II diabetes might be at greater risk for contracting TB. This study also further suggested that: 
- Type-II diabetes, especially type-II diabetes involving chronic high blood sugar, is associated with altered immune response to TB, and this was particularly marked in patients with chronically high blood sugar
- Patients with diabetes and TB take longer to respond to anti-TB treatment
- Patients with active TB and type-II diabetes are more likely to have multi-drug resistant TB.

"The other problem is that if in a family if somebody has diabetes, and another person in same family has TB, then the chance of the person with diabetes acquiring TB becomes high" said Dr Kapur.

"As with TB, which often occurs in social-economically less well-off people, people living in crowded places, in urban environments where they don't have access to care, and are often smoking and they also consume alcohol, many of these same risks apply to diabetes" said Dr Kapur. "So what is starting to happen is that diabetes is much more often seen in people who are poor in the developing countries and also in countries where there is a high burden of TB" further added Dr Kapur. 

Also the environment in which TB happens is the one where diabetes is occurring. "This has very dangerous portents especially for countries like India where we have a very high level of diabetes and a very high level of TB" said Dr Kapur. In fact there have been studies that have been published which estimates that the level of tuberculosis caused by diabetes might be quite substantial in India. 

"If you look at from an individual point of view, if a person is living with HIV, then the risk of TB is 7 to 8 times and the risk of developing diabetes is 2 to 3 times. But at the population level there are far more people with diabetes (50 million) than with HIV in India (close to 2.5 million). So at population level the risk which diabetes causes to TB control programmes is much bigger from public health point of view because of the larger number people with diabetes" said Dr Kapur.

"This is something we are trying to advocate for that in countries where there is a double burden of risk (associated with diabetes and TB) we need to do programmes where people with TB are screened for diabetes, because often people with diabetes have no symptoms especially when they have another serious infection where symptoms are kind of merged with symptoms of diabetes. So we should screen these people for diabetes" advised Dr Kapur.

Similarly people with diabetes who complain of persistent cough for more than two weeks, the doctors should be aware of the double risk (for TB and diabetes) and therefore should investigate these people for potential risk for TB. So this is something we are working with the International Union Against Tuberculosis and Lung Disease (The Union) and also with Stop TB programme of WHO. In addition to that we have funded programmes where we are doing this kind of screening and training of community healthcare workers who are working in areas with TB to look for diabetes. One such programme is right now ongoing in Tamil Nadu, India, with diabetes research centre and National TB Research Institute in Chennai. There is another one being undertaken in China" said Dr Kapur.

One clear learning from being part of single-issue specific programmes like TB control programme, tobacco control programme, AIDS care initiatives, diabetes and others, is to collaborate - synergise - join forces. It reminds me of the words of Dr Michel Sidibe, Executive Director of the joint United Nations programme on HIV/AIDS (UNAIDS) "If a virus (HIV) and a bacteria (TB) can work so well together, then why can't we?" This similar argument is quite pertinent for diabetes and TB programmes, where both conditions have joined hands and posing enormous public health challenge. I do believe such collaborative public health approach will yield positive public health outcomes, keeping fingers crossed for a healthy future.