Diabetes in Cameroon : Classification problems in Africa

Diabetes is a major health problem in Africa where management is complicated by poor socioeconomic conditions. Atypical presentations of diabetes appear to be common in tropical countries although there is still little accurate data in this regard. We describe 550 diabetic patients treated in Cameroon between December 1990 and July 1994. According to WHO criteria 136 of these patients (24.7%) were classified as insulin-dependent (IDDM), 405 (73.5%) as non-insulin-dependent (NIDDM), and 9 as secondary diabetes (1.6%) related to other diseases. There were no cases of malnutrition-related diabetes but 18 patients (3%) met the criteria for "African diabetes" defined by Cuisinier-Raynal. Study of this cohort revealed several differences with diabetic populations in industrialized countries. Insulin-dependent diabetes was observed in all age groups with a mean age of onset of 40.0 ± 14.8 years which is close to the mean age of onset of non-insulin-dependent diabetes (49 ± 10.9 years). The overall M/F sex ratio was 1.63 demonstrating a clear-cut male predominance. There was a high incidence of non-insulin-dependent diabetes in young, non-obese subjects. In many cases classification was difficult because insulin requirements fluctuated greatly. The incidence of obesity in non-insulin-dependent diabetic patients was lower than in industrialized countries. These findings suggest the existence of a tropical diabetes syndrome unrelated to malnutrition. Thus African diabetes appears to be another aspect of the disease which has a variety of heterogeneous etiologic features that cannot be classified on the basis of available data. The current WHO system does not take atypical African diabetes into account.