Study Links Type 2 Diabetes Mechanisms to BMI in African Adults

What The Researchers Reported

Research published in Diabetologia by Amsterdam University Medical Centers and the University of Ghana reports that type 2 diabetes can manifest in two different ways depending on body mass index (BMI).

The report says type 2 diabetes at higher BMI is primarily driven by insulin resistance, while in lower BMI ranges it is driven by the pancreas failing to produce enough insulin, despite both groups often receiving the same medications.

What The Evidence Shows And Who It Applies To

The authors describe the work as a multi-cohort analysis using data from more than 3,300 African adults with type 2 diabetes from Ghana, Nigeria, Kenya, and Europe.

Based on those data, the researchers concluded that lean patients more often develop eye damage (retinopathy) and strokes, while overweight patients more often have high blood pressure and an increased risk of cardiovascular disease. They reported chronic kidney disease occurred equally often in both groups.

Treatment Context Raised By The Article

The article notes that, in Africa, both lean and overweight groups are commonly treated according to international guidelines using oral tablets such as metformin or sulfonylureas.

It adds that these medicines are mainly effective against insulin resistance rather than an insulin shortage, and argues that this could mean lean patients are often receiving treatment that does not match their dominant disease mechanism.

Risk Factors The Authors Connect To Lean Type 2 Diabetes

The researchers report that the amount of body fat explains many of the observed differences, which they say points to different disease processes.

They also describe different risk-factor patterns: overweight is often linked to an unhealthy lifestyle, while lean patients have more often experienced malnutrition or low birth weight, which they say can disrupt pancreatic development.

Implications Mentioned For Africans Living In Europe

The article says the treatment mismatch may also matter for people of African descent living in Europe, where a substantial proportion may have type 2 diabetes at lower BMI than is typical in European populations.

It cites an analysis of UK Biobank data reporting that people of African descent with a BMI of 26 already have the same diabetes risk as Europeans with a BMI of 30. It also states that studies of migrants in Europe consistently find Africans are more likely to have type 2 diabetes, develop it around 10 years earlier, and have poorer blood sugar control than the native population.

Limitations And What The Authors Say Needs To Happen Next

The report describes differences in mechanisms and complications based on observational data analysis, and it does not present results from a treatment trial that tests different therapies in lean versus overweight groups.

The authors call for targeted clinical trials to determine which treatments work best for lean patients with type 2 diabetes, and they argue this group is large and often overlooked in current care pathways.

• Study design: multi-cohort analysis; not an interventional treatment trial.
• Population in the analysis: African adults with type 2 diabetes from Ghana, Nigeria, Kenya, and Europe.
• Clinical next step proposed by the authors: targeted clinical trials for lean type 2 diabetes populations.