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Caffeine, mental stress, and risk for hypertension: a cross-cultural replication
L Greenstadt1, L Yang, D Shapiro
1Department of Psychiatry and Biohavioral Sciences, University of California, Los Angeles 90024.
Insights
Caffeine and mental stress increase systolic blood pressure, but caffeine does not worsen stress effects. A family history of hypertension amplifies blood pressure responses to caffeine and stress.
Area of Science:
- Cardiovascular Physiology
- Human Physiology
- Pharmacology
Background:
- Hypertension is a significant global health concern.
- Understanding factors influencing blood pressure reactivity is crucial for prevention.
- Caffeine and psychological stress are common modulators of cardiovascular function.
Purpose of the Study:
- To investigate the independent and combined effects of caffeine and mental arithmetic stress on systolic blood pressure (SBP) and heart rate (HR).
- To examine whether a family history of hypertension influences cardiovascular responses to caffeine and stress.
Main Methods:
- Double-blind, placebo-controlled study involving 36 Chinese nationals.
- Participants received 0, 125, or 250 mg of caffeine across three sessions.
- SBP and HR were measured following caffeine administration and mental arithmetic stress, with a 12-hour caffeine abstention period prior to each session.
Main Results:
- Both caffeine and mental stress independently elevated SBP.
- Caffeine did not potentiate the SBP response to mental stress.
- No significant effect of caffeine on HR was observed.
- Individuals with a family history of hypertension showed greater SBP increases with higher caffeine doses and during initial mental stress exposure.
Conclusions:
- Caffeine and mental stress are independent stressors affecting SBP.
- Individuals with a family history of hypertension exhibit heightened cardiovascular reactivity to caffeine and acute stress.
- These findings reinforce the concept of increased cardiovascular risk in genetically predisposed individuals.
Abstract:
Separate and combined effects of caffeine and mental arithmetic stress on systolic blood pressure (SBP) and heart rate (HR) were assessed in a double-blind, placebo-controlled study. Thirty-six Chinese nationals, half with and half without a family history of hypertension, received either 0, 125, or 250 mg of caffeine in three separate experimental sessions, each preceded by a 12-hour abstention from caffeine consumption. Caffeine and mental stress elevated SBP, but caffeine did not potentiate the SBP response to mental stress. Caffeine did not affect HR. A positive family history of hypertension was associated with larger SBP elevations to the higher dose of caffeine. Family history of hypertension was associated with larger blood pressure elevations during mental stress, but only under conditions of high-level stimulation provided by the initial exposure to the stress. These results support previous findings of greater cardiovascular reactivity to laboratory stress in individuals at high risk for hypertension.