Pressor effects of caffeine and cigarette smoking

Pressor effects of caffeine and cigarette smoking were examined in 15 normotensive young men and women. A cross-over design was used in which all subjects participated in four separate conditions: placebo alone, caffeine alone, placebo plus smoking, and caffeine plus smoking. Caffeine and smoking produced independent increases in systolic and diastolic blood pressure, and these effects were additive in the caffeine-plus-smoking condition. Heart rate was significantly increased by smoking but was essentially unaffected by caffeine.