The influence of user status and anxious disposition on the hypertensive effects of caffeine

The present study examined the influence of consumer status and anxious disposition on the hypertensive effects of caffeine. A secondary aim of the study was to investigate possible gender differences in response to caffeine. Sixty normotensive subjects were assigned to 4 groups representing high and low scorers on the variables of habitual caffeine consumption and anxious disposition. A randomized double-blind crossover design was used in which all subjects received a placebo (lactose) at one of two 120-min laboratory sessions and caffeine (6 mg/kg) at the other. Systolic and diastolic blood pressure, heart rate, hand steadiness, and EMG were monitored before and after exposure to a psychological stressor. Caffeine produced significant elevations in systolic and diastolic blood pressure, and these effects were additive to the pressor effects of stress and anxiety. While the general pattern of results was similar for both sexes, reactions to caffeine were more pronounced in males than in females. Notwithstanding the need for clarification of the chronic effects of caffeine, present findings add further weight to current concerns about the acute hypertensive effects of the drug.