Association between personality and the risk of ischemic heart disease mortality before and after the Great East Japan Earthquake: Data from the Miyagi Cohort Study

Background: The purpose of the present study was to investigate the association between personality and the risk of IHD mortality among Great East Japan Earthquake (GEJE) survivors, and to investigate whether personality traits affected the increase in IHD mortality observed after the GEJE.Methods: We analyzed data for 29,065 men and women in the Miyagi Cohort Study who were 40-64 years old at baseline. We divided the participants into quartiles based on scores for each of the four personality subscales (extraversion, neuroticism, psychoticism, and lie), using the Japanese version of the Eysenck Personality Questionnaire-Revised Short Form. We divided the eight years before and after the GEJE event (11 March 2011) into two period, and examined the relationship between personality traits and the risk of IHD mortality. Cox proportional hazards analysis was used to estimate the multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of IHD mortality according to each personality subscale category.Results: In the four years before the GEJE, neuroticism was significantly associated with an increased risk of IHD mortality. Compared with the lowest category for neuroticism, the multivariate-adjusted HR (95% CI) for IHD mortality in the highest category was 2.19 (1.03-4.67) (p-trend = 0.12). In contrast, no statistically significant association between neuroticism and IHD mortality was observed in the four years after the GEJE.Conclusion: This finding suggests that the observed increase in IHD mortality after the GEJE can be attributed to risk factors other than personality.