Clinical aspects of hypertension in Black Jamaicans

ABSTRACT

Hypertension is a major contributor to morbidity and mortality in the Caribbean today but data about this disease in the West Indies is scant and this thesis provides some of such much needed research information with particular emphasis on hypertension in blacks. A prospective analysis of admissions to the Medical Wards of the University Hospital of the West Indies during 1980 and 1981 describes the clinical features of black hypertensive patients. Most of these had developed complications within 10 years of the diagnosis of hypertension, and cardiomegaly, renal failure, cardiac failure and stroke were the commonest sequelae. Unlike the situation with white populations today, myocardial infarction was the least common of all the major complications seen in black Jamaicans. The present study was the first to document the renin profile of black Jamaicans and showed that 19 percent of hypertensives had high renin levels, 46 percent had normal levels and 35 percent had low renin levels, a pattern which was similar to that found in white populations. The infleunce of sickle cell anaemia, another common disease of blacks, on blood prressure measurements was assessed. The data showed that subjects with homozygous sickle cell disease may be protected against the development of hypertension since at every age the mean blood pressure was lower than in normal Jamaicans. In an attempt to rationalise drug therapy for hypertensives in the Caribean, earlier conclusions from Jamaica suggesting that beta-blockers may not be effective in blocks were re-examined in a double-blind trial. It was shown that hypertensive Jamaicans were sensitive to small doses of thiazide diuretics and may be less responsive than whites to conventional doses of beta-blockers, and that combination therapy produced a greater fall in blood pressure than either drug used alone. The thesis documented some of the clinical characteristics of the Jamaican hypertensive, provided data helpful for makin recommendations regarding the management of hypertension in the Caribean, and showed that racial factors may modify some of the manifestations of the disease.(AU)