The association between smoking and hypertension in a population-based sample of Vietnamese men

Objective: The association between tobacco smoking and blood pressure in epidemiological studies remains unclear despite experimental evidence that smoking elevates blood pressure. This study examined the association between smoking and hypertension in a population-based sample of Vietnamese men. Methods: The study utilized a population-based sample of men (n = 910) from a survey of risk factors of noncommunicable diseases in Vietnam. Measurements including behavioural risk factors, body composition, and blood pressure were performed according to internationally standardized protocols. Poisson regression was used to obtain prevalence ratios and 95% confidence intervals (CIs). All analyses were performed using complex survey methods. Results: There were significant trends of increasing prevalence of hypertension with increasing years (P = 0.05) and pack-years (P = 0.03) of smoking after adjusting for age, BMI, and alcohol intake. Relative to never-smokers, the risk of hypertension for those who had smoked for 30 years or more and those who had smoked 20 pack-years or more were 1.52 (95% CI 0.95-2.44) and 1.34 (95% CI 0.94-1.91), respectively. Overall, however, current smokers were not at higher risk of hypertension than never-smokers (prevalence ratio = 1.08, 95% CI 0.70-1.68), and ex-smokers were more likely to be hypertensive than either never-smokers (prevalence ratio = 1.81, 95% CI 1.07-3.06) or current smokers (prevalence ratio = 1.67, 95% CI 1.25-2.23), similarly adjusted. Conclusion: In this population-based sample, hypertension was associated with smoking in a dose-response manner when characterized as number of years of smoking and lifetime cigarette consumption, but was not associated with current smoking status.