The association of blood pressure and dietary alcohol: differences by age, sex, and estrogen use.

This paper presents the results of an analysis of dietary alcohol use and blood pressure in representative population samples from four northern California cities surveyed in 1979-1980 as part of the Stanford Five City Project. The pooled samples included 883 men and 959 women aged 20-74 who were not taking blood pressure medications. Blood pressure was obtained while seated using a standard manometer. Alcohol was assessed by self-report of usual intake. In men, age-specific analysis revealed a positive association between dietary alcohol and both systolic (SBP) and diastolic blood pressure (DBP). The association was linear in men aged 20-34 and 50-74 and was stronger in the oldest men. Both linear and quadratic terms were significant for men aged 35-49. This association remained significant in a linear regression model that included age, relative weight, income, education, physical activity, cigarette use, and untimed urinary sodium/creatinine; for alcohol in ml/day in men aged 50-74, beta = 0.21, p = 0.0001, R2 = 0.32 for SBP; beta = 0.09, p = 0.0002, R2 = 0.18 for DBP. In women, alcohol use was significantly associated with blood pressure only in those above age 49 and was more striking in those not taking estrogens; this association was also independent of the same variables listed above for men (beta = 0.43, p = 0.0001, R2 = 0.23 for SBP; beta = 0.17, p = 0.001, R2 = 0.13 for DBP). Multiple logistic analyses with hypertension as a dichotomous dependent variable and including all subjects showed similar results. These results could be due to any one or more of the following hypotheses: 1) a biologic response to alcohol in older men and in older women that is different from the response in younger persons; 2) a delayed effect of alcohol use on blood pressure; 3) effects of a different pattern of alcohol use in the different age groups; or 4) the presence of some unmeasured confounding factor in the older age groups.