Ethnicity and cardiovascular risk: variations in people of African ancestry and South Asian origin

Abstract

Mortality from coronary heart disease (CHD), stroke and and hypercholesterolaemia are less prevalent in ethnic minority populations in the United Kingdom and unlikely end-stage renal failure are high in South Asian migrants in the UK. This is associated with high prevalence of to explain the differences seen between groups, although each risk factor is likely to contribute to the diabetes and hypertension. These seem to be manifestations of a metabolic syndrome with insulin resistance variation in vascular disease within each group. There is difficulty in reconciling the results of (hyperinsulinaemia) and central obesity (based on high waist-to-hip ratio rather than on conventional measures migration studies (eg, from rural to urban environments) pointing to major environmental influences on the of body mass index). This is associated with sedentary lifestyle, high serum triglycerides and low HDL-choleschanges in cardiovascular risk factors with the consistent pattern of disease of ethnic groups across the world terol.Mortality from stroke and end-stage renal failure are and in subsequent generations, suggesting a certain degree of genetic susceptibility. Important environmenthigh in black migrants to the UK (both Caribbeans and West Africans). However, CHD mortality is low in this gene interplays might be underlying some of these processes. group. This pattern of mortality is associated with high prevalence of hypertension and diabetes. This groupThe detection and management of hypertension and diabetes are still unsatisfactory in inner city areas and tends to be obese (particularly women) according to conventional measures of body mass index and to have show variations by ethnic origin. Strategies for the control of CHD and stroke adopted in European countries hyperinsulinaemia, low serum triglycerides and high HDL-cholesterol. directed mostly to white populations may be inappropriate for ethnic minority populations. Conventional risk factors such as cigarette smoking

Target organ involvement in hypertensive patients in Eastern Sudan

“…23 These differences in hypertension complications may be explained by differences in the prevalence of risk factors such as hypercholesterolaemia and cigarette smoking between ethnic groups which are due to the urbanisation and rapid changes in lifestyle in some sub-Saharan African areas and the Middle East. 24 Furthermore, the present study has also shown that the frequency of target organ involvement is a function of both SBP and DBP although the rate of organ damage may vary among individual hypertensives depending on several poorly understood factors, but the presence of target organ damage confers an increased cardiovascular risk to any given level of BP. 25 Our data also point to the positive association of a long duration of hypertension and the number of cigarettes smoked with the presence of any or all types of target organ involvement.…”

Why is plasma renin activity lower in populations of African origin?

“…Indeed, although blacks have a lower rate of ischaemic heart disease, the incidence of end-stage renal disease in blacks with essential hypertension is much higher compared with whites. 83 The lower rate of ischaemic heart disease in blacks may reflect the different pattern of other risk factors as apart from lower PRA, blacks also have a lower fibrinogen, serum cholesterol and triglyceride and a higher high-density lipoprotein (HDL). 83 On the other hand, the reasons for the greater susceptibility to renal damage in blacks with essential hypertension remain to be established but may be a consequence of abnormalities in the renal haemodynamic adaptations to a high salt diet.…”

“…83 The lower rate of ischaemic heart disease in blacks may reflect the different pattern of other risk factors as apart from lower PRA, blacks also have a lower fibrinogen, serum cholesterol and triglyceride and a higher high-density lipoprotein (HDL). 83 On the other hand, the reasons for the greater susceptibility to renal damage in blacks with essential hypertension remain to be established but may be a consequence of abnormalities in the renal haemodynamic adaptations to a high salt diet. 84 The lower PRA in blacks and the sluggish response to sodium restriction and diuretics raises the question of the importance of the renin system in the blood pressure response to sodium restriction or to pharmacological treatment in black hypertensives.…”

Hypertension and renal failure in Kumasi, Ghana

“…1,2 Studies in the United States 3,4 and Britain 5,6 have shown hypertension to be very common and its complications (stroke, heart failure, renal failure) a major cause of morbidity and mortality in black subjects in these countries.…”