Sex, puberty affects caffeine response in teens

In a study involving 50 prepubescent boys and girls aged 8–9 years and 46 postpubescent teenagers aged 15–17 years, researchers randomly allocated subjects to drink either a caffeinated soft drink, with dosages of 1–2mg/kg, or a placebo soft drink. Post-drink measurements of heart rate and blood pressure were then compared with baseline measurements.

The researchers from the New York State University at Buffalo in the United States found significant cardiovascular responses to caffeine, in terms of increased blood pressure and decreased heart rate in all subjects. However, the postpubertal teenage boys had a much more significant response than the girls.

Furthermore, the researchers found that postpubertal girls had different responses to caffeine depending on the stage of their menstrual cycle, with decreases in heart rate that were greater in the mid-follicular stage and blood pressure increases that were greater in the mid-luteal phase.