Increased coronary heart disease mortality after the Hanshin-Awaji earthquake among the older community on Awaji Island

OBJECTIVES: To investigate the characteristics of earthquake (EQ)-induced coronary heart disease (CHD) deaths. SETTING AND PARTICIPANTS: On January 17, 1995, the south part of Hyogo Prefecture in Japan was struck by a major EQ (Hanshin-Awaji EQ) measuring 7.2 on the Richter scale. We investigated the characteristics of EQ-induced CHD deaths (myocardial infarction and sudden death) in the Tsuna region, which is a community with a large older population (31% of the total of 64,000 residents are 60 years of age or older) and includes the epicenter and one of the most heavily damaged areas. MEASUREMENTS: EQ-related CHD mortality on the basis of direct access to records of physicians who were able to continue services for the EQ victims without interruption by this disaster situation. RESULTS: Coronary heart disease deaths increased for a few months after the EQ, and the total number from January 17 to April 30, 1995, was 45, which was significantly (1.5 times) higher than the 31 deaths during the same period of the previous year (1994). The CHD deaths after the EQ all occurred in individuals more than 60 years of age and had a positive correlation with EQ-induced damages. Concerning the onset time, CHD deaths occurred 1.8 times more often (P <.05) in the nighttime (11 PM to 5 AM) and 1.4 times as often during the morning (5 AM to 11 AM), whereas their occurrence did not vary during a 12-hour period from 11 AM to 11 PM. CONCLUSION: Deaths of older individuals from CHD persisted for a few months after the EQ and were especially prominent during the nighttime and morning. Reduction of stress and related coronary risk factors in this period may suppress CHD deaths after a major EQ.