Hypertensive retinopathy in Afro-Caribbeans and Europeans. Prevalence and risk factor relationships.

Abstract

The prevalence of hypertension is particularly high in people of black African descent throughout the world, and the consequences of hypertension, such as hypertensive heart and renal disease and stroke, are also more common. But there is little consensus on whether hypertensive retinopathy follows a similar pattern. We determined the prevalence of hypertensive retinopathy and its relationships with resting and ambulatory blood pressure in a population study of Afro-Caribbeans and Europeans aged 40 to 64 years in London, UK. Retinal photographs of 651 participants were graded for hypertensive retinopathy. Age- and sex-standardized prevalence of retinopathy was 11% (95% confidence interval, 8% to 14%) in Europeans and 21% (95% confidence interval, 16% to 26%) in Afro-Caribbeans (P < .001), respectively. This ethnic difference in prevalence was greatest in normotensive women (8% in Europeans versus 20% in Afro-Caribbeans, P < .001). Resting systolic pressure was 8 mm Hg higher in normotensive Afro-Carribean compared with European women, but this could not fully account for the ethnic difference in the prevalence of retinopathy. Examination of the different relationships of age and resting and ambulatory blood pressures with hypertensive retinopathy showed that these relationships were strongest in European women and weakest in Afro-Caribbean women. We conclude that hypertensive retinopathy is more common in Afro-Caribbeans, particularly women, and that ethnic differences in resting blood pressure cannot fully account for this. The relatively weak relationship between resting and ambulatory blood pressures and retinopathy in Afro-Caribbeans suggests that factors other than blood pressure determine the high rates of hypertensive retinopathy in this group.