From assumption to evidence about diabetes and tuberculosis

December 2009. Recent reviews reconfirm that diabetes is associated with an increased risk of developing tuberculosis. Yet, recognition from health authorities and strategies for action still need to make headway before all patients will profit from combined care.

Ensuring good links

The vast majority of tuberculosis patients (95%) and diabetes patients (70%) live in developing countries and this poses an extra challenge in terms of finding cost-effective solutions. According to Dr. Knut Lönnroth who is Medical Officer at WHO's Stop Tuberculosis Department, the main challenge ahead for the double burden of tuberculosis and diabetes is to strengthen health systems. "Particularly primary health care in order to reduce the barriers for people with both diseases to access quality health care," he says. "Large numbers of people with both tuberculosis and diabetes are undiagnosed or diagnosed or treated too late due to lack of access to quality diagnosis and treatment. This leads to severe health, social, and economic consequences for these people, for their families and for the community."

"A first practical step to improve this situation is to ensure good links between tuberculosis and diabetes programmes or initiatives, both at clinical and administrative levels. This involves improving diagnosis of tuberculosis in people with diabetes and vice versa, effective referral mechanisms, and optimisation of clinical care for both diseases in line with internationally recommended best practice," says Dr. Lönnroth.

A review was needed

In an effort to gather the existing knowledge on the link between diabetes and tuberculosis, the International Union Against Tuberculosis and Lung Disease (IUATLD), World Diabetes Foundation (WDF) and the WHO Stop TB Department initiated a series of consultations in January 2009. The objective was to initiate a process towards developing a policy document on tuberculosis and diabetes.

Based on these consultations, it was agreed that an additional literature review was needed in order to update any new evidence and highlight the need for early detection of patients with diabetes and tuberculosis respectively. The literature review should also update relevant issues that may affect management of tuberculosis as well as identify evidence regarding the effect of diabetes prevention on the tuberculosis burden.

This additional systematic review was undertaken by Professor Megan B. Murray and her team at the Department of Epidemiology, Harvard School of Public Health. The report on the review findings was prepared and forwarded to key stakeholders from the Union, WDF, WHO, academic institutions and diabetes organisations.

The review merely confirmed the already known link, but most of all it served to thoroughly emphasise the importance of addressing diabetes for strengthening tuberculosis control. While tuberculosis control has been improving with a slow decrease in incidence, the prevalence of diabetes is rapidly increasing. In 2007 an estimated 246 million people were living with diabetes; in comparison, an estimated 14.4 million people were living with tuberculosis the same year (1). Considering this, the increasing prevalence of diabetes may counteract the positive effects of improved treatment for tuberculosis if diabetes is not addressed.

The four Paris recommendations

During an expert meeting held in November at the IUATLD Headquarters in Paris, the review findings were taken one step closer to action. The main objective of the Paris meeting was to determine whether recommendations about joint management of diabetes and tuberculosis could be made as well as to identify research gaps and develop a research agenda. The expert meeting concluded with four recommendations:

1. Collaboration between TB and DM care and control initiatives

The ministries of health, technical agencies, funding agencies and donors should recognise the link between Diabetes Mellitus (DM) and TB and encourage closer collaboration between the national TB programmes (NTP) and stakeholders involved in national DM prevention and care.

2. Screening for active TB among DM people

In countries with a high TB burden, people with DM should be routinely asked for TB symptoms and recent exposure to TB, as part of regular clinical check-ups. Identification should follow standardised TB suspect identification and TB diagnosis procedures.

3. Screening for DM among TB patients

People with newly diagnosed TB should be screened for DM, at least in countries/areas with medium to high prevalence of DM.

4. Management of TB and DM co-morbidity

• Treatment and monitoring of people with DM and active TB should be optimised as per national guidelines and/or international best practice adapted to available resources.
• Cross-referral of TB and DM cases should be ensured, while integrated approaches for diagnosis, management and prevention should be explored.
• Health education and behaviour change messages and interventions should be part of the health education delivered as part of routine encounters with health workers.
• The applicability of the DOTS model (political commitment, quality assured diagnosis, standardized treatment with adequate patient support, ensured drug supply, and standardized monitoring and evaluation) should be explored for the management of DM.

Follow-up in Cancun

In December, at the 40th Union World Conference on Lung Health held in Cancun, Mexico, the issue was given a first time recognition with a full session on diabetes and tuberculosis. "While it is still too early to say that a link has been established, I would rather say that there was mutual recognition of the need to create joint programmes," says Dr. Anil Kapur who attended the Cancun meeting.

Providing documentation and paving the way

China and India are home to the largest populations living with diabetes in Asia with 43 million and 50 million people respectively.(2) On top of this, the two countries hold the unenviable record of having the highest rates of tuberculosis in the region with 1.3 million in China and 1.9 million in India.(3) As diabetes rates increase in both countries, so does the risk of developing tuberculosis.

With the two-fold objective of investigating the association between tuberculosis and diabetes and improving treatment for patients with both diseases, the World Diabetes Foundation initiated support to two projects in India and China in 2009. Over the next three years, health care personnel working with tuberculosis will be trained in screening and management of diabetes while people working with diabetes will learn about screening and management of tuberculosis. Patients with diabetes will be screened for tuberculosis and vice versa. This way, both projects will generate important data and knowledge for developing a model for addressing the double burden of diabetes and tuberculosis.

Source

1. IDF Diabetes Atlas, 2009 & WHO Global TB Control, 2009.
2. IDF Diabetes Atlas 2009.
3. According to WHO WPRO, China had 1,311,184 incidences of all forms of tuberculosis in 2006 (http://www.wpro.who.int/internet/resources.ashx/PUB/docs/TBControl2008.pdf). According to WHO SEARO, India had 1,961,825 incidences in 2008 (http://www.searo.who.int/en/Section10/Section2097/Section2100_14797.htm).