The independent effect of habitual cigarette and coffee consumption on blood pressure

The authors investigated the possible relation between habitual cigarette and coffee consumption and blood pressure (BP) levels in 7506 men and 2095 women. The study population were managers and employees examined in northern Italy between 1986-1988. In particular, the hypothesis of a substantial independence between smoking-BP and coffee-BP was tested. BP levels were corrected for age, body mass index, physical activity, and alcohol consumption by analysis of covariance. Significantly, smoking was inversely related to BP, both in men (SBP, P < 0.001, DBP, P < 0.001) and women (SBP, P = 0.001, DBP, P = 0.012). In particular, the BP of non-smoking men, SBP/DBP, was 131.0/83.5, whereas in male smokers up to and over 20 cigarette/day, BP was 128.1/82.0 and 128.1/82.1 respectively. Coffee consumption was related to BP levels in men (SBP, P < 0.001; DBP, P = 0.009), but not in women (SBP, P = 0.320; DBP, P = 0.982). BP in male subjects was 131.3/83.5 in non-drinkers, 130.7/83.3 in those drinking 1-3 cups/day, 128.4/82.6 and 127.2/81.8 in drinkers of 4-5 and over 5 cups/day, respectively. No significant interactions were demonstrated, thus the relationship between habitual smoking and coffee consumption with BP appears to agree with an additive model.