Burden and determinants of diabetes in sub-Saharan Africa

The prevalence of type 2 diabetes is rising rapidly across sub-Saharan Africa; however, its epidemiology, clinical phenotypes, and underlying mechanisms remain insufficiently characterised. This first paper in a Series on diabetes in sub-Saharan Africa synthesises current evidence on the burden, distribution, and determinants of diabetes, including emerging phenotypes and the roles of early life adversity, psychosocial stress, and interactions with infectious disease. We also identify major gaps in surveillance systems, research capacity, prevention, and clinical management across the region. Sub-Saharan Africa is experiencing one of the fastest global increases in diabetes, with the highest proportion of undiagnosed cases and a projected steep rise in intermediate hyperglycaemia and diabetes by 2050. Urbanisation, ageing, obesity, and lifestyle transitions are major contributors; however, a substantial proportion of type 2 diabetes occurs in lean individuals (BMI <25 kg/m2), particularly in rural settings, suggesting distinct metabolic and developmental pathways not captured by models derived from high-income countries. Bidirectional interactions between diabetes and malaria, tuberculosis, HIV, or COVID-19 make disease trajectories complex. Persistent gaps in surveillance, a reliance on modelled estimates, low genomic representation, and constrained access to modern diabetes medications hinder progress. Strengthening health system capacity, improving data infrastructure, and investing in regionally driven research are essential to develop effective, context-specific interventions and advance precision medicine tailored to sub-Saharan African populations.