The mediating effect of blood pressure between healthy lifestyles and stroke: Results from the China Kadoorie Biobank study

While a healthy lifestyle is known to reduce the risk of stroke, the extent to which blood pressure (BP) mediates this association remains unclear. The present study aimed to quantify the mediating role of BP in the association between combined lifestyle factors and stroke incidence. Using data from 51929 participants free of major cardiovascular diseases or cancer at baseline, we employed structural equation modeling to assess the mediating effects of systolic (SBP) and diastolic (DBP) blood pressure. During the follow-up, 2811 incident stroke cases were identified. A healthy lifestyle was significantly associated with a reduced risk of stroke, with SBP mediating 44.70% (β = −0.0014, 95% confidence interval CI: −0.0016 to −0.0012) and DBP mediating 37.81% (β = −0.0012, 95% CI: −0.0015 to −0.0009) of this association. The mediating effects were attenuated but remained significant for ischemic stroke (SBP: 33.21%; DBP: 27.24%). In conclusion, approximately two-fifths of the protective association between a healthy lifestyle and stroke may be mediated by BP. These findings suggest that BP control may serve as an important early indicator for evaluating the effectiveness of lifestyle interventions in reducing stroke risk.