Diabetes in Africa. Diabetes Microvascular and Macrovascular Disease in Africa

This review on the prevalence and characteristics of diabetes micro- and macrovascular disease in Africa is based on a bibliographical Medline search and diabetes conference proceedings of published data over the past decade. The prevalence of diabetic retinopathy varies from 16 to 77% depending on the duration of diabetes and glycaemic control, with severe retinopathy representing 15% of all cases. At diagnosis, 21-25% of type 2 patients and 9.5% of type 1 patients have retinopathy. The prevalence of nephropathy varies between 32-57% after a mean duration of diabetes of 5-10 years, and 5-28% within the first year following the diagnosis of diabetes. The prevalence of neuropathy varies widely depending on the methodology used. Macrovascular complications of diabetes are considered rare in Africa despite a high prevalence of hypertension. Coronary heart disease may affect 5-8% of type 2 diabetic patients and cardiomyopathy up to 50% of all patients. Lower extremity amputation varies from 1.5 to 7%, and about 12% of all hospitalized diabetic patients have foot ulceration. Neuropathy underlies diabetic foot more often than peripheral vascular disease. In conclusion, whereas microvascular complications of diabetes are highly prevalent and occur early during the course of disease, macrovascular disease is rare. Late diagnosis of diabetes, poor metabolic control and nonstandardized diagnostic procedures rather than genetic predisposition may account for this difference from other populations around the world.