Adaptation to social adversity is associated with stroke incidence: evidence from the EPIC-Norfolk prospective cohort study.

BACKGROUND AND PURPOSE Laboratory-based studies have suggested that individual differences in cardiovascular reactivity and stress adaptive capacity are associated with stroke incidence. We test the hypothesis that sense of coherence (SOC), a marker of social stress adaptive capacity, is associated with incident stroke in a population-based prospective cohort study. METHODS A total of 20,629 participants, aged 41 to 80 years, in the UK European Prospective Investigation into Cancer (EPIC)-Norfolk study, who had not previously experienced a stroke, completed assessments that included SOC and details of their experience of life events during adulthood. An index of adaptation was constructed from responses to questions concerning over 80,000 adverse life events. RESULTS During 145,000 person-years of follow-up (mean 7.1 years), 452 participants experienced either a fatal or nonfatal stroke event. A strong (as opposed to a weak) SOC was associated with a reduced rate of stroke incidence (rate ratio 0.76; 95% CI, 0.60 to 0.96) after adjustment for age, sex, pre-existing myocardial infarction, diabetes, hypertension treatment, family history of stroke, cigarette smoking, systolic blood pressure, obesity, social class, education, hostility and depression. No sex difference in this association was observed. Measures of social adversity occurrence and impact were not associated with stroke incidence, whereas faster reported adaptation to adverse event exposure was associated with a reduced rate of stroke incidence (rate ratio 0.89; 95% CI, 0.81 to 0.98; per standard deviation change in adaptation score, adjusted for age and sex). CONCLUSIONS Stress adaptive capacity is a potentially important candidate risk factor for stroke.