Sick genes, sick individuals, or sick populations with chronic disease? An international example from a standardized study of glucose tolerance and high blood pressure

ABSTRACT

Intensive searches for genes predisposing to or "causing" chronic disease are based on familial patterns indicating gene based inheritance. Rose's paradigm, less popular with clinical scientist thinking in individuals, is that populations give rise to their extreme values who become patients. For diabetes (NIDDM), population-based twin registers (e.g. Denmark) show little mono-to-di-zygotic difference, a suggesting major hospital ascertainment bias in ascribing a genetic basis to NIDDM. Here we examined geographically dispersed populations of West African origin, or similar genetic background within Cameroon, then between Jamaica and African-Caribbean (AfC) migrants to Britain (70 percent from Jamaica). Carefully representive samples were drawn from local population registers in rural and urban Cameroon, Jamaica and Manchester, UK. Results, on similar genetic backgrounds in the Cameroon, and between Jamaica and Manchester, suggest factors affecting energy balance (intake versus expenditure) rather than gene differences determine diabetes and, probably, hypertension rates in these and, probably, most populations.(AU)