Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in Japan
Background Despite the impact of heat exposure caused by global warming, few studies have investigated the hourly effects of heat exposure and the risk of cardiovascular disease (CVD) in the elderly. We examined the associations between short‐term heat exposure and the risk of CVD in the elderly in...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-03-01
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| Series: | Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease |
| Subjects: | |
| Online Access: | https://www.ahajournals.org/doi/10.1161/JAHA.122.027046 |
| _version_ | 1827214930420432896 |
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| author | Ryohei Fujimoto Etsuji Suzuki Saori Kashima Kazufumi Nakamura Hiromichi Naito Atsunori Nakao Hiroshi Ito Takashi Yorifuji |
| author_facet | Ryohei Fujimoto Etsuji Suzuki Saori Kashima Kazufumi Nakamura Hiromichi Naito Atsunori Nakao Hiroshi Ito Takashi Yorifuji |
| author_sort | Ryohei Fujimoto |
| collection | DOAJ |
| description | Background Despite the impact of heat exposure caused by global warming, few studies have investigated the hourly effects of heat exposure and the risk of cardiovascular disease (CVD) in the elderly. We examined the associations between short‐term heat exposure and the risk of CVD in the elderly in Japan and evaluated possible effect‐measure modifications by rainy seasons that occur in East Asia. Methods and Results We conducted a time‐stratified case–crossover study. The study included 6527 residents in Okayama City, Japan, aged ≥65 years who were transported to emergency hospitals between 2012 and 2019 for the onset of CVD during and a few months after the rainy seasons. We examined the linear associations between temperature and CVD‐related emergency calls for each year and for hourly preceding intervals before the emergency call during the most relevant months. Heat exposure during 1 month after the end of the rainy season was associated with CVD risk; the odds ratio (OR) for a 1° C increase in temperature was 1.34 (95% CI, 1.29–1.40). When we further explored the nonlinear association by using the natural cubic spline model, we found a J‐shaped relationship. Exposures 0 to 6 hours before the case event (preceding intervals 0–6 hours) were associated with CVD risk, particularly for the preceding interval 0 to 1 hour (OR, 1.33 [95% CI, 1.28–1.39]). For longer periods, the highest risk was at preceding intervals 0 to 23 hours (OR, 1.40 [95% CI, 1.34–1.46]). Conclusions Elderly individuals may be more susceptible to CVD after heat exposure during the month after the rainy season. As shown by finer temporal resolution analyses, short‐term exposure to increasing temperature can trigger CVD onset. |
| first_indexed | 2024-04-09T23:23:19Z |
| format | Article |
| id | doaj.art-bee042b44fd745cf8895216c1b29adbb |
| institution | Directory Open Access Journal |
| issn | 2047-9980 |
| language | English |
| last_indexed | 2025-03-21T14:39:09Z |
| publishDate | 2023-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease |
| spelling | doaj.art-bee042b44fd745cf8895216c1b29adbb2024-06-22T04:39:10ZengWileyJournal of the American Heart Association: Cardiovascular and Cerebrovascular Disease2047-99802023-03-0112610.1161/JAHA.122.027046Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in JapanRyohei Fujimoto0Etsuji Suzuki1Saori Kashima2Kazufumi Nakamura3Hiromichi Naito4Atsunori Nakao5Hiroshi Ito6Takashi Yorifuji7Department of Epidemiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama JapanDepartment of Epidemiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama JapanEnvironmental Health Sciences Laboratory, Graduate School of Advanced Science and Engineering Hiroshima University Hiroshima JapanDepartment of Cardiovascular Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama JapanDepartment of Emergency, Critical Care and Disaster Medicine, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Okayama University Okayama JapanDepartment of Emergency, Critical Care and Disaster Medicine, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Okayama University Okayama JapanDepartment of Cardiovascular Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama JapanDepartment of Epidemiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama JapanBackground Despite the impact of heat exposure caused by global warming, few studies have investigated the hourly effects of heat exposure and the risk of cardiovascular disease (CVD) in the elderly. We examined the associations between short‐term heat exposure and the risk of CVD in the elderly in Japan and evaluated possible effect‐measure modifications by rainy seasons that occur in East Asia. Methods and Results We conducted a time‐stratified case–crossover study. The study included 6527 residents in Okayama City, Japan, aged ≥65 years who were transported to emergency hospitals between 2012 and 2019 for the onset of CVD during and a few months after the rainy seasons. We examined the linear associations between temperature and CVD‐related emergency calls for each year and for hourly preceding intervals before the emergency call during the most relevant months. Heat exposure during 1 month after the end of the rainy season was associated with CVD risk; the odds ratio (OR) for a 1° C increase in temperature was 1.34 (95% CI, 1.29–1.40). When we further explored the nonlinear association by using the natural cubic spline model, we found a J‐shaped relationship. Exposures 0 to 6 hours before the case event (preceding intervals 0–6 hours) were associated with CVD risk, particularly for the preceding interval 0 to 1 hour (OR, 1.33 [95% CI, 1.28–1.39]). For longer periods, the highest risk was at preceding intervals 0 to 23 hours (OR, 1.40 [95% CI, 1.34–1.46]). Conclusions Elderly individuals may be more susceptible to CVD after heat exposure during the month after the rainy season. As shown by finer temporal resolution analyses, short‐term exposure to increasing temperature can trigger CVD onset.https://www.ahajournals.org/doi/10.1161/JAHA.122.027046cardiovascular diseaseclimate changeend of the rainy seasonheat exposure |
| spellingShingle | Ryohei Fujimoto Etsuji Suzuki Saori Kashima Kazufumi Nakamura Hiromichi Naito Atsunori Nakao Hiroshi Ito Takashi Yorifuji Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in Japan Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease cardiovascular disease climate change end of the rainy season heat exposure |
| title | Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in Japan |
| title_full | Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in Japan |
| title_fullStr | Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in Japan |
| title_full_unstemmed | Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in Japan |
| title_short | Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in Japan |
| title_sort | heat exposure following the rainy season is associated with an increased risk of cardiovascular emergency among the elderly in japan |
| topic | cardiovascular disease climate change end of the rainy season heat exposure |
| url | https://www.ahajournals.org/doi/10.1161/JAHA.122.027046 |
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