Type 2 diabetes prevalence doubles in sub-Saharan Africa in 6 years

In six years, the prevalence of type 2 diabetes has doubled in a group of middle-aged people in South Africa, Kenya, Ghana and Burkina Faso. In the first-ever longitudinal study of its kind in sub-Saharan Africa, data from 10,702 participants revealed the progression of type 2 diabetes at a much higher rate than initial predictions.

Poorly controlled type 2 diabetes can, over time, increase the risk of heart and kidney disease and lead to eye, vascular and nerve damage.

While initial estimations revealed that about 6% of sub-Saharan Africa will have diabetes by 2045 (about 60 million people), researchers now believe this to be a gross underestimation. The present study shows the prevalence is already 10.9%—about twice that estimate.

This is explored further in a study, “Incident type 2 diabetes and its risk factors in men and women aged 40–60 years from four sub-Saharan African countries: results from the AWI-Gen study,” published in The Lancet Global Health. The study succinctly identified the risk factors associated with type 2 diabetes, and thus, mitigating such risk factors is imperative.

“While all sites in the region showed a doubling in the prevalence of type 2 diabetes during the study period, there are still marked differences between the countries. South Africa had the highest incidence of the disease, followed by East Africa and then West Africa,” said co-author Dr. Raylton Chikwati, a post-doctoral fellow affiliated with the Sydney Brenner Institute of Molecular Bioscience (SBIMB) and the Developmental Pathways of Health Research Unit (DPHRU), Wits University.

Chikwati noted that urban communities experienced higher rates of type 2 diabetes and those “at a later stage of epidemiological transition.” In epidemiological transition, chronic illnesses like heart disease, cancer, obesity and diabetes replace infectious diseases as leading causes of death. This shift often parallels economic development and rural-to-urban population migration.

More men than women develop type 2 diabetes

Worldwide, in 2021, about 17.7 million more men than women were living with type 2 diabetes. This disparity was reflected in the sub-Saharan African study, where diabetes rates were higher among men. “We also found that several other baseline factors, such as body mass index (BMI), waist size, high triglycerides and glucose, lack of exercise, unemployment, hypertension, and a family history of type 2 diabetes significantly increase the risk of developing the disease,” said Chikwati.

“Another interesting observation was that individuals from West Africa developed diabetes at lower BMIs compared to those from East and South Africa—which challenges the universal BMI cutoffs of 25 kg/m² in screening recommendations.”

(BMI, or body mass index, is a calculation that estimates how much body fat a person has based on their height and weight, giving a number that indicates whether they are underweight, normal weight, overweight or obese.)

Context-specific health interventions are needed

As the prevalence of type 2 diabetes increases, context-specific interventions are needed to address its risk factors. This will include studying the impact of dolutegravir, an antiretroviral drug used in HIV management, which is known to cause weight gain and may influence diabetes risk. Implementing targeted strategies will not only improve health outcomes but also reduce the burden on poorly resourced regional health care systems. “We need to realize that the problem is urgent and is not in the distant future,” he says.

The study arose out of the Africa-Wits International Network for the Demographic Evaluation of Populations and Their Health (INDEPTH) Partnership for Genomic Studies (AWI-Gen). AWI-Gen was designed to study genomic and environmental determinants of cardiometabolic diseases in sub-Saharan Africa. Participants were recruited between 2013 and 2017 and followed up between 2018 and 2022.