Influence of weather on daily hospital admissions for acute myocardial infarction (from the Korea Acute Myocardial Infarction Registry)

Background: We investigated the association between meteorological parameters and hospital admissions for acute myocardial infarction (AMI) in a temperate and continental climate, Korea.

Methods: From the Korean AMI Registry, 2136 Koreans admitted for AMI in four university hospitals in Daegu city from November 2005 to October 2007 were included in this study. We calculated the incidences of AMI per season, per month, and per day-of-week. The meteorological parameters, including air temperature, relative humidity, wind speed, sunshine duration, and a thermo-hydrological index, were provided by the database of the Korea Meteorological Administration. Generalized additive Poisson models were used.

Results: Seasonal variations were noted for AMI, characterized by winter peak and summer trough (p<0.001). Monthly occurrence rate of AMI was highest in January and lowest in October (p<0.001). There were significant associations between hospital admissions and meteorological parameters including air temperature, relative humidity, and sunshine duration after controlling for effects of day-of-week, season, and holidays (p<0.05). These associations were stronger in females and the younger age (<65 years) (p<0.01).

Conclusions: The incidence of AMI shows seasonal and monthly variations. Meteorological parameters have a significant influence on the occurrence of AMI, particularly in females and the younger age.