Epidemiology Of Chd In Subsaharan African Populations

Numerous publications have emphasized the rarity of CHD in sub-Saharan African populations. In 1960, CHD was considered extremely rare in Uganda.1 A general review in 1977 noted that Africans were regarded as "virtually free of hypertension and CHD."2 In the same year at Enugu, Nigeria, not 1 patient among 348 with cardiac disorders over a 4-year period had CHD.3 As to international appreciation, a leading article titled "British and African Hearts" published in 1983 in the U.K. emphasized the tremendous contrast between the experiences of CHD in the two types of populations.4 In 1993, a rural hospital in Tanzania reported a low prevalence of CHD risk factors and the absence of the disease.5 The latter phenomenon was also noted in rural Nigeria.6 In a rural hospital at Gelukspan in the Northwest Province of South Africa, none of the 2593 adult admissions in 1994 arose from CHD.7 Around the same time, the same observation related to 2010 admissions was noted at the rural Manguzi Hospital in Kwa-Zulu Natal, South Africa.8

While the rarity described applies particularly to rural dwellers, CHD remains uncommon even in urban populations. In 1976 in Durban, a major city in Kwa-Zulu Natal, about 10 cases were seen annually at King Edward VIII Hospital from a catchment population of about 2 million.9 Angiographic and other studies done in Durban in 1980 reaffirmed that CHD was rare in the black population.10 In 1992, despite rises in risk factors, CHD remained uncommon, 11 as indicated from data noted in 2000.12 In Soweto, a city adjacent to Johannesburg, Gauteng Province, the population of about a million is perhaps the most advanced in a state of transition of African urban populations in sub-Saharan Africa. At Baragwanath Hospital (3200 beds at this writing), according to records of the Department of Cardiology, 35

Africans were diagnosed with CHD in 1992,13 51 in 1993, and 65 in 1994.14 However, of the 65 diagnosed in 1994, only 36 were Sowetans; the rest lived elsewhere. In 2000, the hospital treated 50 Sowetan CHD patients. This is still a very low annual incidence rate of approximately 5.0 per 100,000 population.15At urban Pirenyatwa Hospital, the main referral center for neighboring Zimbabwe, six African patients on average were diagnosed annually with acute myocardial infarction from 1988 to 1993.16 In 1996 in Nigeria, a comprehensive review concluded, "CHD is still rare ... despite increased incidence in recent years."17 Clearly, CHD remains uncommon among urban Africans in South Africa and other sub-Saharan African countries.1318 Regarding a perspective on the epidemiological situation described, one important question is: how does the uncommonness of CHD in Africans compare in magnitude with its high frequency in socioeconomically better placed Western populations? In Soweto, sick Africans usually attend Baragwanath Hospital. If we assume that all of the 50 CHD patients mentioned earlier ultimately died from CHD, then CHD would be responsible for only about 1% of the roughly 5000 deaths occurring annually in that city,19 thereby underlining the low proportion dying from CHD, even when allowing for uncertainties. As to comparisons with proportions in Western countries, in the recently reported Seven Countries Study covering populations in Mediterranean areas and those residing inland, the age-standardized 25-year CHD mortality rate percentages were 4.7 and 7.7%, respectively.20 However, the proportions reported for countries in Northern Europe and the U.S. were far higher, namely 16.0 and 20.3%, respectively. These comparisons further demonstrate the relative rarity of CHD in urban Africans.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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