Effects of temperature and humidity on acute myocardial infarction hospitalization in a super-aging society

Yoshihiro J Akashi,Michikazu Nakai,Takumi Higuma,Tomoo Harada,Shunichi Doi,Yoko Sumita,Masaki Izumo,Yuki Ishibashi,Yoshihiro Miyamoto,Hisao Ogawa,Toshiki Kaihara,Mika Watanabe,Kihei Yoneyama,Satoshi Yasuda,Yasuhiro Tanabe

doi:10.1038/s41598-021-02369-x

Abstract

Weather conditions affect the incidence of acute myocardial infarction (AMI). However, little is known on the association of weather temperature and humidity with AMI hospitalizations in a super-aging society. This study sought to examine this association. We included 87,911 consecutive patients with AMI admitted to Japanese acute-care hospitals between April 1, 2012 and March 31, 2015. The primary outcome was the number of AMI hospitalizations per day. Multilevel mixed-effects linear regression models were used to estimate the association of the average temperature and humidity, 1 day before hospital admission, with AMI hospitalizations, after adjusting for weather, hospital, and patient demographics.Lower temperature and humidity were associated with an increased number of AMI hospitalizations (coefficient − 0.500 [− 0.524 to − 0.474] per °C change, p < 0.001 and coefficient − 0.012 [− 0.023 to − 0.001] per % change, p = 0.039, respectively). The effects of temperature and humidity on AMI hospitalization did not differ by age and sex (all interaction p > 0.05), but differed by season. However, higher temperatures in spring (coefficient 0.089 [0.025 to 0.152] per °C change, p = 0.010) and higher humidity in autumn (coefficient 0.144 [0.121 to 0.166] per % change, p < 0.001) were risk factors for AMI hospitalization. Increased average temperatures and humidity, 1 day before hospitalization, are associated with a decreased number of AMI hospitalizations.

Highlights

Weather conditions affect the incidence of acute myocardial infarction (AMI)
The baseline characteristics of the study population are shown in Association between weather conditions and AMI hospitalizations
The multilevel mixed-effects linear regression analysis shown in Table 2 indicates that a number of incident AMI hospitalizations were associated with lower average weather temperatures and humidity after adjustments for season, hospital, and patient demographics

Summary

Introduction

Little is known on the association of weather temperature and humidity with AMI hospitalizations in a super-aging society. The effects of temperature and humidity on AMI hospitalization did not differ by age and sex (all interaction p > 0.05), but differed by season. Higher temperatures in spring (coefficient 0.089 [0.025 to 0.152] per °C change, p = 0.010) and higher humidity in autumn (coefficient 0.144 [0.121 to 0.166] per % change, p < 0.001) were risk factors for AMI hospitalization. Little is known on the association of weather temperature and humidity with AMI hospitalizations in the superaging society of Japan. To address these issues, we conducted an observational study using the Japanese registry of all cardiac and vascular diseases (JROAD) database. The present study provides important insights on the risk of AMI in the aging Japanese society

Methods

Results

Discussion

Conclusion