Association between ambient temperature and cause-specific cardiovascular disease admissions in Japan: A nationwide study

Rui Pan; Akira Okada; Hayato Yamana; Hideo Yasunaga; Ryosuke Kumazawa; Hiroki Matsui; Kiyohide Fushimi; Yasushi Honda; Yoonhee Kim

doi:10.1016/j.envres.2023.115610

Association between ambient temperature and cause-specific cardiovascular disease admissions in Japan: A nationwide study

Environ Res. 2023 May 15:225:115610. doi: 10.1016/j.envres.2023.115610. Epub 2023 Mar 4.

Authors

Rui Pan¹, Akira Okada², Hayato Yamana³, Hideo Yasunaga⁴, Ryosuke Kumazawa⁴, Hiroki Matsui⁴, Kiyohide Fushimi⁵, Yasushi Honda⁶, Yoonhee Kim⁷

Affiliations

¹ Department of Global Environmental Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
² Department of Prevention of Diabetes and Lifestyle-Related Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
³ Data Science Center, Jichi Medical University, Shimotsuke, Japan; Department of Clinical Epidemiology and Health Economics, The University of Tokyo, Tokyo, Japan.
⁴ Department of Clinical Epidemiology and Health Economics, The University of Tokyo, Tokyo, Japan.
⁵ Department of Health Policy and Informatics, Tokyo Medical and Dental University, Tokyo, Japan.
⁶ Faculty of Health and Sport Sciences, University of Tsukuba, Japan; Center for Climate Change Adaptation, National Institute for Environmental Studies, Japan; School of Tropical Medicine and Global Health, Nagasaki University, Japan.
⁷ Department of Global Environmental Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: yoonheekim@m.u-tokyo.ac.jp.

PMID: 36871945
DOI: 10.1016/j.envres.2023.115610

Abstract

Background: Substantial evidence suggests that non-optimal temperatures can increase the risk of cardiovascular disease (CVD) mortality and morbidity; however, limited studies have reported inconsistent results for hospital admissions depending on study locations, which also lack national-level investigations on cause-specific CVDs.

Methods: We performed a two-stage meta-regression analysis to examine the short-term associations between temperature and acute CVD hospital admissions by specific categories [i.e., ischemic heart disease (IHD), heart failure (HF), and stroke] in 47 prefectures of Japan from 2011 to 2018. First, we estimated the prefecture-specific associations using a time-stratified case-crossover design with a distributed lag nonlinear model. We then used a multivariate meta-regression model to obtain national average associations.

Results: During the study period, a total of 4,611,984 CVD admissions were reported. We found cold temperatures significantly increased the risk of total CVD admissions and cause-specific categories. Compared with the minimum hospitalization temperature (MHT) at the 98^th percentile of temperature (29.9 °C), the cumulative relative risks (RRs) for cold (5^th percentile, 1.7 °C) and heat (99^th percentile, 30.5 °C) on total CVD were 1.226 [95% confidence interval (CI): 1.195, 1.258] and 1.000 (95% CI: 0.998, 1.002), respectively. The RR for cold on HF [RR = 1.571 (95% CI: 1.487, 1.660)] was higher than those of IHD [RR = 1.119 (95% CI: 1.040, 1.204)] and stroke [RR = 1.107 (95% CI: 1.062, 1.155)], comparing to their cause-specific MHTs. We also observed that extreme heat increased the risk of HF with RR of 1.030 (95% CI: 1.007, 1.054). Subgroup analysis showed that the age group ≥85 years was more vulnerable to these non-optimal temperature risks.

Conclusions: This study indicated that cold and heat exposure could increase the risk of hospital admissions for CVD, varying depending on the cause-specific categories, which may provide new evidence to reduce the burden of CVD.

Keywords: Cardiovascular disease; Hospital admissions; Morbidity; Temperature.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged, 80 and over
Cardiovascular Diseases* / epidemiology
Cold Temperature
Cross-Over Studies
Hospitalization
Hot Temperature
Humans
Japan / epidemiology
Myocardial Ischemia*
Stroke* / epidemiology
Stroke* / etiology
Temperature