Abstract P393: Relationship of Caffeine Consumption to Blood Pressure: The INTERMAP Study
Background: Caffeine is the most consumed active stimulant. About 80% of adults in the US consumed caffeine from coffee, tea, cola beverages, energy drinks, chocolate and medication. Although caffeine consumption is known to increase blood pressure (BP) acutely, long term caffeine-BP relations are not well defined. Latest National Institute for Health and Clinical Excellence (NICE) guidelines on primary hypertension in adults (2011) added a new recommendation (<5 cups coffee/day) to discourage excessive consumption of coffee and other caffeine-rich products, as part of antihypertensive lifestyle interventions.
Objective: To investigate associations of dietary caffeine with BP among 2,195 US men and women ages 40-59 from the International Collaborative Study on Macro-/Micronutrients and Blood Pressure (INTERMAP).
Methods: The INTERMAP Study is a cross-sectional epidemiologic investigation with standardized quality-controlled methods; four 24-hour dietary recalls, 2 timed 24-hour urine collections, 8 BP measurements and questionnaire data were accrued. For all US participants associations of BP with consumption of caffeine were assessed by multiple linear regression - - possible confounders included: age, gender, population sample, special diet, use of dietary supplement, diagnosis of cardiovascular disease or diabetes, medium/heavy physical activity (hours/day), family history of hypertension, 24-hr urinary sodium and potassium excretions, smoking, intakes of alcohol, sugar, cholesterol, total saturated fatty acids (FA) and total polyunsaturated FA.
Results: Average caffeine consumption was 127.1 mg/1,000 kcal; most popular caffeine rich products were coffee (75% of total caffeine intake), cola beverages (13%) and tea (11%). With height and weight also controlled, there was a non-significant positive association between total dietary caffeine intake and BP in all regression models. Adjusted for multiple possible confounders, differences in systolic and diastolic BP were 0.7 mm Hg (95% CI, -0.4 to 1.8) and 0.6 mm Hg (-0.1 to 1.4) respectively for caffeine intake higher by 2 SD (262.8 mg/1000kcal), equivalent to 2-3 cups of coffee. In sensitivity analyses, data for normotensive persons were qualitatively similar to the foregoing. For hypertensive participants, difference in systolic BP was 3.5 mm Hg (0.6 to 6.4) for caffeine intake 2 SD higher (P-value<0.05).
Conclusion: Higher caffeine intake may raise systolic BP in normotensive persons; among hypertensive persons, caffeine consumption relates significantly to BP. The recent guideline on reducing caffeine intake is a relevant target for lifestyle management of hypertensive persons.
- © 2013 by American Heart Association, Inc.