Combined lifestyle factors are associated with the risk of ischaemic stroke in a Chinese population.

PURPOSE Lifestyle plays an important role in the development of ischaemic stroke (IS). The objective of this study was to evaluate the association between combined lifestyle factors and the risk of IS in an eastern Chinese population. METHODS We collected lifestyle information from 191 patients with IS admitted to the second affiliated hospital of Soochow University and 575 control subjects from community clinics using a structured questionnaire. After division into training and test datasets, regularised stepwise logistic regression, least absolute shrinkage and selection operator regression and genetic algorithm models were used to identify lifestyle factors associated with IS. The improved discriminative ability by adding the lifestyle factors was determined by c-index and reclassification analysis. The final model was validated in the test dataset. RESULTS After controlling for conventional cardiovascular disease (CVD) risk factors, preferences for fruits (OR (95% CI): 0.29 (0.18-0.46), p<0.001) and soy products (0.47 (0.29-0.75), p=0.002) were negatively associated with IS, while lower life satisfaction (mildly satisfied: 2.15 (1.27-3.63), p=0.004; not satisfied: 6.39 (1.76-25.44), p=0.006) was positively associated with IS. Adding these factors to a basic CVD risk model improved the c-index (0.825 vs 0.753, p<0.001) and reclassification for IS (net reclassification index (95% CI): 18.49% (7.90%-29.08%), integrated discrimination index (95% CI): 0.11% (0.08%-0.14%), p<0.001). The model with lifestyle factors achieved a c-index of 0.813 and good calibration in the test dataset. CONCLUSIONS Our results showed that combined lifestyle factors including dietary pattern and life satisfaction are independently associated with the risk of IS.