Black-white differences in stroke incidence in a national sample: the contribution of hypertension and diabetes mellitus

Statistical and demographic studies have consistently shown the risk of stroke to be greater in both black men and women than in whites. Many of these studies have implicated the higher rates of diabetes and hypertension (high blood pressure) among blacks as being related to their increased stroke mortality. This assumption is tested in a new statistical analysis of national health data. A group of 1,298 Afro-American and 7,814 whites, aged 35 to 74 years, were followed for a period of ten years. The statistical model separates and removes the excessive risks associated with either diabetes or hypertension, and demonstrates that the risk of stroke in both male and female blacks is greater than the corresponding risk in white males and females. Analysis of the effect of race on stroke risk in individuals with either hypertension or diabetes was not statistically different; the risk of hypertension or diabetes causing a stroke in a black individual was not greater than in a white person. Although the reduction of hypertension, and the control of diabetes remain important therapeutic goals for controlling the risk of stroke, other unknown factors are involved in the elevated stroke risk for blacks. (Consumer Summary produced by Reliance Medical Information, Inc.)