Coffee and caffeine consumption and the risk of hypertension in postmenopausal women

Abstract

Background: The associations of coffee and caffeine intakes with the risk of incident hypertension remain controversial.

Objective: We sought to assess longitudinal relations of caffeinated coffee, decaffeinated coffee, and total caffeine intakes with mean blood pressure and incident hypertension in postmenopausal women in the Women's Health Initiative Observational Study.

Design: In a large prospective study, type and amount of coffee and total caffeine intakes were assessed by using self-reported questionnaires. Hypertension status was ascertained by using measured blood pressure and self-reported drug-treated hypertension. The mean intakes of caffeinated coffee, decaffeinated coffee, and caffeine were 2-3 cups/d, 1 cup/d, and 196 mg/d, respectively. Using multivariable linear regression, we examined the associations of baseline intakes of caffeinated coffee, decaffeinated coffee, and caffeine with measured systolic and diastolic blood pressures at annual visit 3 in 29,985 postmenopausal women who were not hypertensive at baseline. We used Cox proportional hazards models to estimate HRs and their 95% CIs for time to incident hypertension.

Results: During 112,935 person-years of follow-up, 5566 cases of incident hypertension were reported. Neither caffeinated coffee nor caffeine intake was associated with mean systolic or diastolic blood pressure, but decaffeinated coffee intake was associated with a small but clinically irrelevant decrease in mean diastolic blood pressure. Decaffeinated coffee intake was not associated with mean systolic blood pressure. Intakes of caffeinated coffee, decaffeinated coffee, and caffeine were not associated with the risk of incident hypertension (P-trend > 0.05 for all).

Conclusion: In summary, these findings suggest that caffeinated coffee, decaffeinated coffee, and caffeine are not risk factors for hypertension in postmenopausal women.

Keywords: blood pressure; caffeinated coffee; caffeine; decaffeinated coffee; hypertension.

FIGURE 1

Study population selection from the Women’s Health Initiative Observational Study. Of 93,676 postmenopausal women in the Women’s Health Initiative Observational Study cohort, we excluded 182 women with missing data on baseline blood pressure and 39,962 women with hypertension at baseline (systolic blood pressure or diastolic blood pressure ≥140 or ≥90 mm Hg and women being treated for hypertension). We then excluded 8054 women with missing systolic and diastolic blood pressure measurements at the year 3 visit. We also excluded 14,347 women with missing data on primary exposures of interest, including caffeinated coffee, decaffeinated coffee, and/or caffeine intakes. After further exclusion of 1146 women with missing data on the main covariate variables, the analytic sample comprised 29,985 participants.