Incidence of hypertension and educational attainment: the NHANES I epidemiologic followup study. First National Health and Nutrition Examination Survey.

Previous research has demonstrated the association between cardiovascular disease and education. However, few studies have described the incidence of hypertension, a risk factor for cardiovascular disease, by education or other socioeconomic status indicators. To examine the association between hypertension incidence and education, the authors analyzed data from the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Followup Study (NHEFS) (1971-1984). The relative risk of hypertension incidence (blood pressure > or =160/95 and/or using antihypertensive medication) by education was calculated for non-Hispanic Whites (aged 25-64 years) and non-Hispanic Blacks (aged 25-44 years) normotensive at baseline using Cox proportional hazards models. The age-adjusted relative risk of hypertension incidence among persons with less than 12 years of education compared with those with more than 12 years was significant among non-Hispanic Whites aged 25-44 years (men: relative risk (RR) = 2.14, 95% confidence interval (CI): 1.29, 3.54; women: RR = 2.06, 95% CI: 1.39, 3.05) but not among non-Hispanic Blacks (RR = 1.16, 95% CI: 0.63, 2.14). Relative risks for non-Hispanic White men remained stable after adjusting for age, systolic blood pressure, body mass index, and region of residence; relative risks for non-Hispanic White women were reduced but remained significant. Non-Hispanic White men and women aged 45-64 years with less than 12 years of education were not at higher risk of developing hypertension compared with their more educated counterparts. These results demonstrate a significant interaction between age and education with an independent association between education and hypertension incidence among younger but not older non-Hispanic White men and women.