Smoking and the risk of incident hypertension in middle-aged and older men.

BACKGROUND

Cigarette smoking is a known risk factor for cardiovascular disease (CVD), but its relationship to the development of hypertension is unclear. Previous epidemiological studies have shown inconsistent results, having demonstrated inverse and positive associations between cigarette smoking and the development of hypertension.

METHODS

We analyzed 13,529 male participants from the Physicians' Health Study free of baseline hypertension and CVD who provided information about smoking status. Smoking status was categorized as never, past, or current <20 cigarettes/day, or current > or =20 cigarettes/day. Incident hypertension was defined as either the initiation of antihypertensive treatment, self-reported systolic blood pressure (BP) > or =140 mm Hg, or diastolic BP > or =90 mm Hg.

RESULTS

Over a median follow-up of 14.5 years, 4,904 men developed hypertension. We modeled the risk of developing hypertension by baseline smoking status adjusting for known risk factors for hypertension or CVD. In a fully adjusted Cox proportional hazards model, we found that compared with never smokers, past smokers and current smokers had corresponding relative risks (RRs) of 1.08 and 1.15 of developing hypertension. The risk for smokers did not appear to differ based on number of cigarettes smoked daily. Further, the RR of hypertension was higher for men with normal vs. prehypertensive levels of systolic (SBP) or diastolic BP (DBP).

CONCLUSIONS

This prospective cohort data suggests that cigarette smoking may be a modest but important risk factor for the development of hypertension.