PLOS ONE, 2014, 01, e94070─e94070

Short-Term Effect of Temperature on Daily EmergencyVisits for Acute Myocardial Infarction with Threshold Temperatures

Suji Lee, Eunil Lee, Myung Ho Jeong, Seung-Woon Rha

Abstract

Background
The relationship between temperature and myocardial infarction has not been fully explained. In this study, we identified the threshold temperature and examined the relationship between temperature and emergency admissions due to MI in Korea.
Methods
Poisson generalized additive model analyses were used to assess the short-term effects of temperature (mean, maximum, minimum, diurnal) on MI emergency visits, after controlling for meteorological variable and air pollution (PM10,NO2). We defined the threshold temperature when the inflection point showed a statistically significant difference in the regression coefficients of the generalized additive models (GAMs) analysis. The analysis was performed on the following subgroups: geographical region, gender, age (〈75 years or ≥75 years), and MI status (STEMI or non-STEMI).
Results
The threshold temperatures during heat exposure were for the maximum temperature as 25.5-31.5℃ and for the mean temperature as 27.5？28.5℃. The threshold temperatures during cold exposure were for the minimum temperature as 22.5？1.5℃. Relative risks (RRs) of emergency visits above hot temperature thresholds ranged from 1.02 to 1.30 and those below cold temperature thresholds ranged from 1.01 to 1.05. We also observed increased RRs ranged from 1.02 to 1.65 of emergency visits when temperatures changes on a single day or on successive days.
Conclusions
We found a relationship between temperature and MI occurrence during both heat and cold exposure at the threshold temperature. Diurnal temperature or temperature change on successive days also increased MI risk.

• ISBN or ISSN: 1932-6203

• 본 연구는 질병관리본부 연구개발과제(과제번호 2013-E21002-01) 연구비를 지원받아 수행되었습니다.
• This research was supported by a fund(code 2013-E21002-01) by Research of Korea Centers for Disease Control and Prevention.