Hypertension, alcohol drinking and stroke incidence: A population-based prospective cohort study among inner Mongolians in China

OBJECTIVES: The purpose of this study was to evaluate the effect of hypertension and alcohol drinking on stroke incidence and whether alcohol drinking would increase the risk of stroke in hypertension participants among Inner Mongolians. METHODS: A prospective cohort study from June 2003 to July 2012 was conducted among 2535 people aged 20 years and older from Inner Mongolia, China. We categorized the participants into four subgroups according to blood pressure and drinking status. The cumulative risks of stroke among the four subgroups were estimated with the Kaplan-Meier curves and compared by log-rank test. Cox proportional hazards models and receiver operating characteristic (ROC) curves were employed to evaluate the association between hypertension, alcohol drinking and stroke incidence. RESULTS: A total of 120 stroke patients were observed during the follow-up period. The multivariate-adjusted hazard ratios (95% confidential intervals) of stroke for nonhypertension/drinkers, hypertension/nondrinkers and hypertension/drinkers were 1.03 (0.48-2.22), 2.64 (1.45-4.81) and 2.89 (1.55-5.39), respectively, compared with nonhypertension/nondrinkers. The area under ROC curve (AUC) for a model containing hypertension and drinking status along with conventional factors (AUC=0.684) was significantly (P=0.005) larger than one containing only conventional factors (AUC=0.660). CONCLUSION: These findings suggest that hypertension is an independent risk factor of stroke in Inner Mongolians. Drinkers with hypertension seem to be more susceptible to stroke; larger-sample prospective cohort studies are still required to examine the cumulative effect of drinking and hypertension on stroke incidence.