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Caffeine and hypertension
Insights
This study found that prolonged caffeine intake did not significantly elevate blood pressure or related markers in hypertensive individuals. Short-term caffeine use may cause minor, temporary blood pressure increases.
Area of Science:
- Cardiovascular Pharmacology
- Clinical Hypertension Research
Background:
- Hypertension is a significant global health concern.
- Caffeine is a widely consumed stimulant with potential cardiovascular effects.
- Understanding caffeine's impact on blood pressure in hypertensive patients is crucial.
Purpose of the Study:
- To investigate the long-term effects of caffeine administration on blood pressure.
- To assess changes in plasma catecholamine levels and plasma renin activity.
- To evaluate caffeine's safety and efficacy in managing blood pressure in hypertensive subjects.
Main Methods:
- A double-blind, placebo-controlled study design.
- Eighteen hypertensive subjects received either placebo or caffeine (250 mg three times daily) for seven days.
- Blood pressure, plasma catecholamine, and plasma renin activity were monitored.
Main Results:
- A transient, non-significant increase in systolic blood pressure was observed after the initial caffeine dose.
- No significant long-term elevations in systolic or diastolic blood pressure were noted.
- Plasma catecholamine levels and plasma renin activity showed no significant changes.
Conclusions:
- Prolonged caffeine administration does not lead to significant sustained increases in blood pressure in hypertensive patients.
- Caffeine appears safe for individuals with borderline hypertension regarding blood pressure and key hormonal markers.
- No adverse cardiovascular events or significant hormonal alterations were observed during the study period.
Abstract:
The effect of prolonged caffeine administration on blood pressure in hypertensive subjects was assessed in a double-blind placebo-controlled study. Eighteen hypertensive subjects participated, nine of whom received placebo throughout the study and nine of whom received placebo during the first three days, caffeine during the subsequent seven days, and placebo during the final four days of the two-week study. Those who received caffeine were given 250 mg with meals three times daily. There were no untoward reactions in the course of the study, but one subject with unacceptably high blood pressures while receiving placebo had to be discharged from the study to resume antihypertensive therapy. Systolic blood pressure was immediately increased (9.2 +/- 3.4 mm Hg) within 15 minutes after the first dose of 250 mg of caffeine. On the first day of caffeine, systolic pressure was increased a mean of 7.3 +/- 4.0 mm Hg, but this was no longer significant after the initial day of caffeine administration. Diastolic pressure showed a trend toward increasing, but this never reached significance. The minor increases in plasma catecholamine levels and plasma renin activity were not significant on either a short- or long-term basis. After discontinuation of caffeine, no overshoot phenomena were observed. It is concluded that prolonged administration of caffeine is not associated with significant elevation in blood pressure, plasma catecholamine levels, or plasma renin activity in patients with borderline hypertension.