Rising Hospitalization Risk for Heatstroke Among People with Lifestyle-Related Diseases in Japan

According to a new analysis from Sumitomo Life Insurance Co., individuals who suffer from lifestyle-related diseases are significantly more prone to hospitalization stemming from heatstroke. This report, which reflects escalating concerns about heatstroke in Japan due to global warming, reveals that those with pre-existing health conditions are at a two to five times higher risk than their healthier counterparts.

The findings were derived from a comprehensive "heatstroke white paper" that examined health records of approximately 10 million people. The study, which includes data collected in 2023 and 2024, notes that health status directly affects the severity of heatstroke. For example, individuals on blood pressure medication face a 3.5-fold increase in risk, while those managing diabetes see a 4.9 times higher risk. Additionally, people using medications for lipid disorders have a 2.2 times greater likelihood of being hospitalized for heatstroke when compared to non-users.

Several health issues and medications contribute to this heightened risk, including those that lead to fluid loss and dehydration. Conditions like arterial sclerosis can also impair circulation, making it more challenging for the body to regulate heat effectively. Lifestyle factors such as consuming evening meals before bedtime, inadequate sleep, smoking, and significant weight gain since the age of 20 further increase the chances of needing intravenous fluids or other medical intervention for heatstroke. Insufficient sleep is particularly noted for its adverse effects on temperature regulation, while smoking exacerbates circulation issues.

The summers of 2023 and 2024 stand out as historically high in temperature, with the Japan Meteorological Agency recording some of the hottest weather since it began tracking in 1898. The Ministry of Health, Labor, and Welfare reported 1,651 deaths attributed to heatstroke in 2023, as temperatures consistently reached or surpassed 35 degrees Celsius during the day and remained elevated overnight. In light of these findings, Sumitomo Life Insurance emphasizes the necessity of managing health conditions and adopting lifestyle changes such as engaging in moderate exercise and gradually acclimatizing to higher temperatures to mitigate heatstroke risk.