Effects of passive smoking on hypertension in rural Chinese nonsmoking women

BACKGROUND: Increasing evidence suggest that active smoking is a risk factor for hypertension, but little is known about the effects of passive smoking on this condition. In China, female passive smoking is widespread and severe due to the high proportion of men who smoke, particularly in rural areas. This study assessed whether passive smoking is associated with increased risk of hypertension among nonsmoking women in rural China. METHODS: A total of 392 nonsmoking women from a rural area of Shanxi Province (northern China) participated in this cross-sectional study. Data on female passive smoking, and other factors known to influence hypertension, were collected during face-to-face interviews. Logistic regression was used to evaluate the association analyses after adjusting for potential confounders. RESULTS: In total, 162 of the 392 participants were hypertensive (41.3%); 118 participants (30.1%) reported exposure to passive smoking, of whom 88.4% were exposed to smoke in the home. After adjusting for age, BMI, education, occupation, drinking status, physical activity, and menopause status, passive smoking conferred an approximately two-fold risk increase of hypertension (adjusted odds ratio = 1.99, 95% confidence interval 1.16, 3.39). The adjusted odds ratios for passive smoking exposure levels of one to three, four to six, and more than six occasions per week were 1.01 (0.39-2.62), 2.57 (1.05-6.30), and 2.59 (1.18-5.69), respectively. CONCLUSION: In rural areas of northern China, female passive smoking in the home is prevalent. Frequent exposure to secondhand smoke is a risk factor for hypertension among nonsmoking women, which suggests that measures should be taken to prevent passive smoking among this population.