Mean ± SEM changes in average heart rate (HR) (A) diastolic blood pressure (DBP) (B), and systolic blood pressure (SBP) (C) between 0- and 2-mg/kg doses of caffeine in prepubertal and postpubertal boys and girls. Because there were no effects of time and no differences between the 1- and 2-mg/kg doses, the data shown are the average changes from baseline and are from the 2-mg/kg condition. There were no gender differences in any of the measures in the prepubertal participants, but there were gender differences in all of the postpubertal participants. *Significantly different from postpubertal boys, P < .05.
Mean ± SEM changes in heart rate, diastolic blood pressure (DBP), and systolic blood pressure (SBP) in postpubertal girls in the follicular and luteal phases of the menstrual cycle. Caffeine administration lowered heart rate significantly more in the luteal phase compared with the follicular phase and increased SBP and DBP significantly more in the follicular phase compared with the luteal phase (all P < .05).