The association of smoking and hypertension according to cotinine-verified smoking status in 25,150 Korean adults

Purpose: The establishment of a definitive association between smoking and hypertension has been controversial in previous studies, many of which were based on self-reported smoking status and urine cotinine-verified smoking status. The aim of the current study was to evaluate the association between hypertension and smoking considering the effects of all kinds of smoker types, including hidden smokers, using new variables and a population-based sample.

Methods: Data were acquired from 25,150 men and women aged older than 29 years who participated in the Korea National Health and Nutrition Examination Survey (KNHANES).

Results: The prevalence of hypertension was 4.7%, that of self-reported smoking was 30.8%, and that of cotinine-verified smoking was 28.5%. Of the male cotinine-verified smokers, 5.6% were self-reported nonsmokers (1.5% never-smokers and 4.1% ex-smokers), whereas, of the female cotinine-verified smokers, 46.9% were self-reported nonsmokers (40.8% never-smokers and 6.1% ex-smokers). Multivariate logistic regression analysis revealed that, with respect to self-reported smoking status, smokers and ex-smokers were not correlated with hypertension [(odds ratio (OR): 1.25 (95% confidence interval (CI): 0.99–1.57) and OR: 1.20 (CI: 0.90–1.60), respectively]. When gender was considered, the adjusted OR of the association of smoking with hypertension in female participants was 1.44 (CI: 1.02–2.04) with respect to cotinine-verified smoking status.

Conclusion: This large observational study found that smoking was not associated with hypertension in the overall population, but, when the gender was considered, female smokers were more likely to demonstrate hypertension.