Effects of cigarette smoking on blood pressure stratified by BMI in Mongolian population, China

BACKGROUND: The relationship between smoking and hypertension is still unclear and controversial; we examine effects of smoking on blood pressure stratified by body mass index (BMI) in the Mongolian population. METHODS: A total of 2589 Mongolians aged 20 years or more were recruited as study subjects. Demographic data, lifestyle factors, family history of hypertension, blood pressure measurements, physical examination and blood sample were obtained and analyzed for all subjects. RESULTS: Among subjects with BMI<25 kg/m(2), adjusted mean diastolic blood pressure in all smokers (82, 83 and 82 mmHg for subjects who smoke 1-9, 10-19 and >20 cigarettes/day, respectively) were lower than that in non-smokers (84 mmHg), all p-values <0.05; among subjects with BMI>25 kg/m(2), mean systolic blood pressure (137 mmHg for non-smokers, 141, 135 and 132 mmHg for subjects who smoke 1-9, 10-19 and >20 cigarettes/day, respectively) decreased with amount of smoking and linear trend was statistically significant, p<0.05. Multivariate adjusted odds ratios of hypertension for three smoking groups were all not statistically significant. CONCLUSIONS: This study did not provide support that smoking was a risk factor of hypertension and elevated blood pressure.