Clustering of cardiovascular risk factors and stroke: a prospective cohort study in Inner Mongolia.

OBJECTIVE: This study aimed to evaluate the effect of clustering of cardiovascular risk factors (CVRF) on stroke incidence and find some high predictive clusters among Inner Mongolians in China.

METHODS: A prospective cohort study was conducted among 2589 participants aged 20 and older from Inner Mongolia, China. The participants were divided into four groups according to the number of CVRFs and followed up from June 2002 to July 2012. Cox proportional hazards model was used to evaluate the clustering of CVRFs on the incidence of stroke. Area under curve was used to compare the effect of every cluster on stroke and find those having higher predictive value.

RESULTS: A total of 124 stroke occurred during the follow-up period. The incident stroke cases tended to be older and male; had higher prevalence of smoking, drinking, and family history of cardiovascular diseases (FHCVD); had greater waist circumference, higher systolic and diastolic blood pressure, and C-reactive protein levels at baseline compared with those who did not experience stroke. Unadjusted hazard ratio (HR) (95% confidence interval) of stroke in the participants with at least three CVRFs was 5.230 (2.646-10.336), compared with those without CVRF. After multiple adjustments, the result remained statistically significant (HR, 3.388; 95% confidence interval: 1.678-6.840). On the basis of FHCVD, clustering of hypertension with other CVRFs and clustering of diabetes with tachycardia had higher predictive value than other clustering.

CONCLUSION: The clustering of CVRFs increased the risk of stroke. On the basis of FHCVD, the clustering of hypertension with other CVRFs and the clustering of diabetes with tachycardia had higher predictive value for stroke than other cluster.