Abstract

ASSOCIATION OF CIGARETTE SMOKING WITH INCREASED RISK OF HYPERTENSION-A PROSPECTIVE STUDY FROM NORTH INDIA

Premshanker Singh*, Ritu Karoli and Shobhit Shakya

ABSTRACT

This study was undertaken for prospective evaluation of cigarette smoking and its association with an increased risk of developing hypertension. Smoking is a well-recognized risk factor for cardiovascular disease. Few prospective cohort studies have exam ined the relationship between smoking and hypertension. We conducted a prospective study among 2824 women who were initially free from hypertension and cardiovascular disease. Detailed risk factor information, including smoking status was collected from self-reported questionnaires. We used Cox proportional hazards survival models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident hypertension (defined as either new diagnosis, the initiation of antihypertensive medication, systolic blood pressure >140 mm Hg or diastolic blood pressure >90 mm Hg). At baseline, 51% of women were never smokers, 36% were former smokers, 5% smoked 1 to 14 cigarettes, and 8% smoked >15 cigarettes per day. During a median of 2.5 years, there were 8, 57 (30.4%) cases of incident hypertension. The age-adjusted HRs of developing hypertension among never, former, and current smokers of 1 to 14 and >15 cigarettes per day were 1.00 (reference), 1.04 (95% CI 0.99 to 1.09), 1.00 (95% CI 0.90 to 1.10), and 1.10 (95% CI 1.01 to 1.19), respectively. In multivariable models further adjusting for lifestyle, clinical and dietary variables, the corresponding HRs were 1.00 (reference), 1.03 (95% CI 0.98 to 1.08), 1.02 (95%CI 0.92 to 1.13), and 1.11 (95% CI 1.03 to 1.21), respectively. Among women who smoked >25 cigarettes perday, the multivariable HR was 1.21 (95% CI 1.06 to 1.39). In this study population of women, cigarette smoking was modestly associated with an increased risk of developing hypertension, with an effect that was strongest among women smoking at least 15 cigarettes per day. Smoking and hypertension are two leading causes of death worldwide and it has been claimed that smoking is a cause of hypertension despite inconsistent results in the literature. In addition, the literature focuses mostly on developed countries, although more people in developing countries are adversely affected by smoking and hypertension.

Keywords: Smoking, Hypertension, Cardiovascular.