An estimated 350 million people have diabetes worldwide, including those in poorer countries where other diseases, particularly tuberculosis (TB), are prevalent. To combat both diseases, the World Health Organization (WHO) is now asking diabetes and infectious disease experts to collaborate on activities for the prevention and care of both diseases.
Researchers estimate that more than 80% of diabetes-related deaths occur in low- and middle-income countries, and it is predicted that global diabetes prevalence will jump by 50% by 2030.1
Data also indicate that people with diabetes are known to be at a higher risk for progressing from latent to active TB, and their risk for TB in general is two to three times higher, as compared with people without diabetes, according to WHO.
“There is now a greater awareness of the problem, but the degree of collaboration that we need is not going on yet,” William Schaffner, MD, who is the past president of the National Foundation for Infectious Diseases and a professor of preventive medicine at Vanderbilt University in Nashville, Tennessee, said. “We need to do a lot more.”
Dangers of Concurrent TB, Diabetes
Recently, infectious disease researchers have become more concerned that the rapidly increasing prevalence of diabetes is jeopardizing the progress they have made in tackling TB, especially in places where the disease is considered an epidemic, like low- and middle-income countries.
In The Lancet Diabetes & Endocrinology, researchers reported that substantial progress has been made in reducing the incidence of TB during the past two decades. However, with diabetes reaching epidemic proportions during the last 30 years, they are concerned that they will not see the same type of improvement over the next two decades.
Diabetes appears to be the cause of 15% of current TB cases, and the fact that diabetes impairs host defenses makes treatment of patients affected by both diseases extremely difficult — a situation that is further exacerbated in low-income settings.2
Moreover, studies show that people with concurrent diabetes experience worse TB treatment outcomes. They have a higher rate of relapse following TB treatment, and mortality rates are also higher for people with diabetes than they are for people without diabetes.
Consequently, WHO currently recommends that all TB patients be screened for diabetes and that screening for TB in patients with diabetes should be considered, particularly in settings with high TB prevalence.1
Prevention, Treatment Strategies
In a recent review of the link between TB and diabetes, researchers concluded that coordinated planning and service delivery across communicable and non-communicable disease programs is now necessary.3 The researchers noted that coordinated planning and delivery of adequate care across communicable and non-communicable disease programs are feasible and could “create synergies” that will help reduce the burden of both diabetes and TB.
Additionally, the researchers advocated for trials that will establish the indications for treatment of latent TB infection in people with diabetes. They also concluded that there should be screening for and treatment of latent TB infection in people with diabetes who are close contacts of a patient with active TB as well as others with a high likelihood of recent infection.
“We need to do smarter testing. This will require more resources,” Schaffner said in an interview with Endocrinology Advisor. “Treating early matters and affects downstream health care.”
Daniel Hoft, MD, PhD, who is the director of the division of infectious diseases at Saint Louis University in Missouri, said that for decades, physicians and public health officials have been treating patients with diabetes and TB differently than patients with only TB. However, because diabetes rates are increasing at such high rates, there now needs to be greater efforts to coordinate care.
“We have considered patients with latent TB infection to be some of the highest priority candidates for isoniazid chemoprophylaxis to prevent TB disease progression. In addition, patients with diabetes mellitus and TB disease are followed more closely during treatment. Emphasizing the link is important to make sure all physicians and public health officials are more vigilant in patients with both TB and diabetes mellitus,” Hoft told Endocrinology Advisor.
Stopping the Obesity, Diabetes Epidemics
Hoft noted that infectious disease and endocrine specialists commonly work together to help with individual patients because controlling the infection and diabetes are both extremely important. Nevertheless, he said efforts must be increased due to the obesity and diabetes epidemics.
“Public health measures that would focus on reducing obesity and therefore decrease risks of adult-onset diabetes could be very helpful. Reducing the risks of diabetes associated with obesity could reduce the TB risks,” Hoft said.
Health care providers and policymakers must also ramp up efforts to stop the new wave of type 2 diabetes occurring in young children, according to David Clemmons, MD, who is a professor of biochemistry and biophysics at the University of North Carolina (UNC) Diabetes Care Center in Chapel Hill.
Addressing exercise and eating habits among children in a much more aggressive way is now required, he said.
“There are many different approaches. The most broad are public health measures, the most important being childhood education about nutrition and exercise to prevent obesity. Thirty years ago, we almost never saw type 2 diabetes in children. Now, [children] comprise more than half of the new cases, and this is due to weight gain in the general population and changes in dietary habits,” Clemmons told Endocrinology Advisor.
Michael Hence, MD, who is with the UNC Institute for Global Health and Infectious Diseases, said this current effort by WHO should be applauded, as mobilizing resources for non-communicable diseases is long overdue.
What is urgently needed in countries most affected by the dual epidemics of TB and diabetes is continued investments in the health system, according to Hence. There needs to be a new goal toward strengthening human resources to improve access to high-quality treatment for both diseases.
“Certainly diabetes and infectious disease experts coordinate care for patients in well-resourced health systems for infections more commonly seen in diabetics, such as diabetic foot ulcers and rhino-cerebral mucormycosis,” Hence told Endocrinology Advisor.
“However, in many low- and middle-income countries, the health systems often simply do not have enough health care workers and medical resources to effectively co-manage diabetes and TB outside of large referral hospitals, let alone support dedicated diabetes and ID experts who can manage each disease in a coordinated fashion.”
- World Health Organization. Tuberculosis and Diabetes. http://www.who.int/tb/publications/diabetes_tb.pd. Accessed July 2015.
- The Lancet Diabetes & Endocrinology. Diabetes and tuberculosis—a wake-up call. Lancet Diabetes Endocrinol. 2014;2(9):677.
- Lönnroth K et al. Lancet Diabetes Endocrinol. 2014;2(9):730-739.