Will diabetes add the last straw on the burdened back of TB?

Shobha Shukla, Citizen News Service - CNS
According to a new Series about TB and diabetes, published in The Lancet Diabetes and Endocrinology, the rapid increase in rates of type-2 diabetes, especially in low- and middle-income countries where TB is endemic, could thwart global efforts to control and eliminate TB. Currently there are 8.6 million cases of TB annually and the worldwide population of people living with diabetes is 382 million.

A 52% increase in diabetes prevalence recorded over the last 3 years in the 22 highest TB burden countries has possibly increased the incidence of diabetes-associated TB cases from 10% in 2010 to 15% in 2013 (1 million cases per year). India and China together account for more than 40% of these cases. In fact India holds the dubious distinction of having the highest number of adult diabetes associated TB cases—302,000-- and also the maximum global burden of TB—2.2 million cases per year.

Dr Anthony Harries,
The Union
In an interview with Citizen News Service (CNS), Dr Anthony Harries, an expert in this field and Senior Advisor to International Union Against Tuberculosis and Lung Disease (The Union) explained that, "People with diabetes have weakened immune systems, for reasons that are not entirely clear, putting them at risked risk of TB infection. It seems that the white cells that keep the TB and other bacteria under check do not work as well in people with diabetes. There is evidence to suggest that diabetes increases the risk of active TB by about three times and those whose diabetes is out of control are at higher risk of developing TB because of their weakened immunity and possibly exposure to undiagnosed TB in their clinics. Furthemore people with both diabetes and TB have a poorer response to anti-tuberculosis treatment with a higher risk of failure, death or relapse after cure."

“While people with diabetes are at increased risk of getting TB, the converse is not true. TB does increase stress on the body and may lead to increased levels of blood glucose but these usually subside when the infection comes under control. But in some cases TB might unmask diabetes and this will manifest as continued raised blood glucose levels even after treatment for TB has taken effect.”

The International Diabetes Federation (IDF) predicts that the global diabetes prevalence in adults will increase from 8% (382 million cases) in 2013 to about 10% (592 million cases) in 2035. This increase of 55% in the number of people living with diabetes in the next two decades is likely to reduce the fall in TB incidence by about 3%.

Need for collaborative activities
The emerging double burden of diabetes and TB thus threatens to undermine TB control efforts especially with regards to reducing the incidence of TB. The countries which have a high TB burden are also experiencing increasing incidence rates of diabetes.

Dr Harries stressed upon the need of stepping up collaborative activities on diabetes and TB at the national, district and local level. He said that, “India has taken a lead in this and it has a national policy to screen all TB patients for diabetes. However in other countries this is happening sporadically if at all. The ideal solution would be for this bi-directional screening to take place in an integrated fashion in just one place rather than in different clinics. However, screening of diabetes patients for TB has not really taken off for perhaps reasons such as lack of a public health model in diabetes and screening for TB being perceived by doctors treating diabetes as waste of time and scarce resources.”

Dr Ashwani Khanna
It would be pertinent to mention here that Dr Ashwani Khanna, Senior Physician at Lok Nayak Hospital, Delhi and also the State TB Control Officer, has been testing all patients undergoing TB treatment in his hospital for diabetes for quite some time—under the same roof—with no extra burden on the patients.

A coordinated planning and service delivery across communicable and non-communicable disease (NCDs) programmes will help to reduce the burden of both TB and diabetes.

Community-driven solutions

It is important to address the global diabetes epidemic in order to help improve TB prevention and optimize clinical care for people with TB/diabetes co-morbidity. This cannot be achieved without actively involving the community. According to Dr Harries better attention to and control of diabetes-TB will occur as a result of better community involvement--“People need to be made more aware of the two diseases. Globally, 3 million (nearly 33%) TB patients are not notified to the TB programme settings and nearly 50% of the patients with diabetes do not know that they have diabetes. Thus, there needs to be more intensive education of the community about the two diseases and about the interaction between the two. If a patient has one of these diseases, he/she needs to be screened for the other disease and the community needs to assist in this to happen. This is all the more pertinent for people living in high TB burden countries—if they have one of these diseases they need to think about the other too.”

“The best way to prevent TB in a person with diabetes is to ensure that his/her blood glucose levels are kept as well controlled as possible. Already, many patients with diabetes in developed countries manage their disease through self monitoring of their blood glucose levels with hand-held machines and make their own adjustments to insulin dosages based on their day-to-day blood glucose control.”

Incidentally the theme of the forthcoming 45th Union World Conference on Lung Health in Barcelona, organized by the International Union Against Tuberculosis and Lung Disease (The Union) is "Community-driven solutions for the next generation". This theme recognises the essential role of affected persons and communities, whose input must be integrated with that of other experts for the conception and implementation of interventions. The Union and the World Diabetes Foundation (WDF) will be also be releasing the first policy report on diabetes-TB at this conference.

The proposed post 2015 sustainable development goals (SDGs) also take cognizance of reducing mortality from non communicable diseases (NCDs) and ending the epidemic of TB by 2030, (Goal 3 on health). This, coupled with Goal 2 to end hunger and improve nutrition, can go a long way to break the nexus between the two diseases. Ideally, elimination of world hunger would address over and under nutrition, and so would be coupled with a decrease in obesity and thus in diabetes, which in turn would augment TB prevention efforts.

According to the Lancet Report, mathematical modeling suggests that increased prevention, recognition and control of diabetes might lead to a 15% decrease in global TB incidence by 2035. Alternatively, an unchecked and escalating diabetes epidemic could lead to an 8% increase in tuberculosis incidence by 2035. It all depends how well we do in the coming years with responding to the diabetes epidemic.

Shobha Shukla, Citizen News Service (CNS)
10 October 2014
(The author is the Managing Editor of Citizen News Service - CNS.
Lilly MDR TB Partnership is supporting CNS Correspondents' Team to provide thematic coverage from the 45th Union World Conference on Lung Health in Spain. She is a J2J Fellow of National Press Foundation (NPF) USA and received her editing training in Singapore. She has earlier worked with State Planning Institute, UP and taught physics at India's prestigious Loreto Convent. She also co-authored and edited publications on gender justice, childhood TB, childhood pneumonia, Hepatitis C Virus and HIV, and MDR-TB. Email: shobha@citizen-news.org, website: www.citizen-news.org)