Trends in the incidences of acute myocardial infarction in coastal and inland areas in Japan: The Yamagata AMI Registry.

Background: It has been reported that there are regional differences in the incidence of acute myocardial infarction (AMI) in Japan. The purpose of this study was to investigate trends in regional differences in AMI incidence and dyslipidemia between coastal and inland areas.
Methods: We investigated trends in AMI incidence and risk factors in 5325 first-ever AMI patients residing in a coastal area (n=1817), a rural inland area (n=1959), or an urban inland area (n=1549) for the periods 1994-2002, and 2003-2010, using data from the Yamagata AMI Registry.
Results: Patients in the coastal area were significantly older than those in rural and urban inland areas and had a lower prevalence of dyslipidemia. The age-adjusted incidence rate of AMI was significantly lower in coastal and rural inland areas patients than those from urban inland area (males: 43.3, 42.2, and 51.3/10(5) person-years; females: 17.4, 20.0, and 23.7/10(5) person-years, respectively) during 2 observation periods. Due to a large increase in AMI incidence in younger males of the coastal area and a decrease in AMI incidence in late elderly females of the urban inland area, no significant regional differences in the age-adjusted incidence rates of AMI were observed during the 2003-2010 period in both genders. The increase in AMI incidence in males in the coastal area was associated with an increasing prevalence of dyslipidemia.
Conclusion: There were no longer any regional differences observed in AMI incidence, which was considered to be associated with increased dyslipidemia especially in the coastal area.
(Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)