Epidemiology of cardiovascular diseases in Africa with special reference to Kenya: an overview

At the beginning of this century, high blood pressure was virtually non-existent among the indigenous Kenyans. This phenomenon of normotension continued until the Second World War following which the Kenyan African began to exhibit progressive rise in blood pressure which was age-related. Similar changes were observed in Uganda at the same time. From about 25 years ago, high blood pressure became established in Kenya and the neighbouring countries, in particular Uganda. These trends have been observed in West Africa notably Ghana, Nigeria, Cote d'Ivoire and also in Cameroon and Zaire in the Central African region. Consumption of sodium salt and alcohol, psychological stress, obesity, physical inactivity and other dietary factors are thought to play important aetiologic role in the genesis of primary hypertension in the susceptible individuals. Low blood pressure communities still exist scattered all over the world, where blood pressure does not seem to rise with age. In Africa these have been observed in Kenya, Nigeria, Zaire and Kalahari Desert. They also exist in Pacific island, Australia, South America and elsewhere. Rural-urban migration coupled with acculturation and modernization trends have some relationship with the development of high blood pressure as observed in Kenyan and Ghanian epidemiologic studies.