Ethnic and socio-economic inequalities in coronary heart disease, diabetes and risk factors in Europeans and South Asians.

BACKGROUND: The aim of this study was to test the hypothesis that in Europeans and South Asians (Indians, Pakistanis, Bangladeshis) alike, worse socio-economic status is associated with a higher prevalence of coronary heart disease (CHD), glucose intolerance (impaired glucose tolerance and diabetes) and related risk factors (the predicted direction of association).

METHODS: Cross-sectional data were analysed from a community-based prevalence study seeking associations between social class, education and Townsend deprivation score and ECG evidence of CHD, glucose tolerance test and 12 cardiovascular risk factors. The study population consisted of South Asians (n = 684) comprising Indians (n = 259), Pakistanis (n = 305) and Bangladeshis (n = 120), and Europeans (n = 825), aged 25-74 years in Newcastle. The analysis examined up to 84 associations for each ethnic group. Interactions between ethnicity and socio-economic variables were examined using regression analysis. The main outcome measure was the number of associations in the predicted direction.

RESULTS: Europeans fared better in some indicators of socio-economic position, South Asians in others. Indians were socio-economically advantaged compared with Pakistanis and Bangladeshis. Most measures of socio-economic position were associated with health measures in the predicted direction in Europeans [71/84 (85 per cent) associations, 25 statistically significant] and less so in the South Asians combined [58/84 (69 per cent) associations, 12 statistically significant]. In South Asian men 25/42 (60 per cent) of associations were as predicted, seven significantly so, in women 33/42 (79 per cent) were, five being statistically significant. There were apparent differences between Indians 152/78 (67 per cent) of associations as predicted, seven statistically significant], Pakistanis [41/84 (49 per cent), four statistically significant] and Bangladeshis [39/79 (49 per cent), one statistically significant]. In Indians, Townsend deprivation score was mostly associated as predicted [23/27 (85 per cent), five associations statistically significant], more so than social class [14/27 (52 per cent), none statistically significant]. In South Asian men and women combined, associations with anthropometric [18/24 (75 per cent)], biochemical [15/18 (83 per cent)], and lifestyle 114/18 (78 per cent)] measures were often as predicted, but those with blood pressure (4/12, 33 per cent) and CHD and glucose intolerance (7/12, 58 per cent) were less often so. Interactions between socio-economic position and ethnicity were found.

CONCLUSIONS: The European pattern of inequalities is being established in South Asian men and women, possibly at a different pace in different subgroups. Future studies of inequalities should be large, separate Indian, Pakistani and Bangladeshi populations, study men and women separately and track changes over time.