What is the risk of coronary heart disease in South Asians? A review of UK research

Objective The aim of this study was to systematically review the evidence that coronary heart disease risk is higher in South Asians than in comparative 'white' populations, particularly seeking studies of incidence. Methods A systematic literature review was carried out using a personal research literature collection, MEDLINE 1966-1998 and citations from references. Results Of 19 studies, none reported disease incidence. Most studies reported prevalence, mortality rates or health care utilization data. Most studies were on people born on the Indian subcontinent, thus omitting the British-born. Several did not report on women. The strongest evidence of an excess of CHD in South Asians came from mortality data comparing those born in the Indian subcontinent with the whole population of England and Wales. In South Asians coronary heart disease is common and important, but neither the actual disease rates nor the excess risk in relation to the 'white' population are known. Both prevalence and mortality data suggested that the frequency of coronary heart disease in Indians, Pakistanis and Bangladeshis differed. Conclusion Estimates of South Asians' excess risk of coronary heart disease are imprecise and may be too high (if there are data errors) or too low (for comparison with the general population blunts ethnic variations). South Asians are a heterogeneous group yet most studies of CHD report on Bangladeshis, Indians and Pakistanis combined. Indians probably have less CHD than Bangladeshis and Pakistanis. Cohort studies on CHD in South Asians are needed and these should be designed so that data can be combined for future systematic reviews.