World TB Day – Understanding the risk of other diseases for people with a history of TB

Published: 24 March 2021

Tuberculosis (TB) is responsible for more than a million deaths worldwide every year, with more than ten million cases occurring annually. While the disease itself is both curable and preventable, it still has a devastating impact. This is why, every year, the World Health Organisation marks World TB Day, as a chance to raise awareness about the disease and step up efforts to reduce its prevalence.

Here at St George’s, we are leading on multiple studies to tackle the disease, including basic research to understand how the bacteria that causes the disease remains dormant in the body, and clinical trials to improve treatment of the disease.

Another area that needs to be understood is whether TB raises the risk of developing other diseases,  even after treatment. It is well known that some infections and chronic illnesses like diabetes can increase the risk of developing other conditions, but for TB there is very little information available.

To try and uncover the answer, a new partnership between researchers at St George’s and Emory University in the USA has been set up to try and examine TB patient data and see whether people diagnosed with TB are at increased likelihood of future disease.

Funded by the National Institutes of Health in the USA, the study will feature two large cohorts of people from the UK and USA; two countries with high migration from countries affected by TB.

Professor Julia Critchley from the Population Health Research Institute at St George’s is Principal Investigator for the study. Speaking about the work, she said, “There are suggestions and possible mechanisms for how TB may lead to changes that put people at greater risk of conditions like diabetes and heart attacks. This could be due to metabolic changes brought about by the disease or drugs used to treat it.

“Our research will identify people that are at higher risk of disease. If we can better understand the magnitude of these risks and who might be affected, you can identify people early on and hopefully intervene and improve their future health.”

Using data from GP practices, hospitals and national statistics, the group will assess the links between having TB and going on to develop conditions like diabetes, pulmonary diseases (e.g. asthma and chronic obstructive pulmonary disease) and cardiovascular diseases (e.g. strokes and heart attacks).

The researchers will also be able to examine whether other factors, such as age, sex, smoking status, obesity and ethnicity, might be playing a role.