Association between heat exposure and intussusception in children in Japan from 2011 to 2022

Exposure to heat may increase the risk of intussusception through various mechanisms, including alterations in dietary intake. However, no nationwide studies have examined the association between daily heat exposure and intussusception in children. This study aims to examine the association between higher daily ambient temperatures and intussusception in children.

The daily number of intussusception hospitalizations among children up to 5 years old from 2011 to 2022 was extracted from Japan's nationwide administrative claims database. Daily mean temperature data were obtained from the Japan Meteorological Agency. Since the focus is on heat exposure, the analysis examines hospitalizations that occurred during the five warmest months (May to September). A time-stratified case-crossover design with conditional quasi-Poisson regression analysis was applied to estimate the relative risk of heat exposure on intussusception with a lag of 0-4 days.

There were 13,083 cases of intussusception hospitalizations. Higher daily mean temperatures were associated with an elevated risk of intussusception hospitalizations. Specifically, exposure to extremely high daily mean temperatures at the 99th percentile was associated with a 39% increase in hospitalization risk (95% CI: 1.05, 1.83).

The study found the association between higher daily mean temperatures and an increased risk of hospitalization for intussusception. Future research should clarify the mechanisms of the association between higher daily mean temperatures and the increased risk of intussusception hospitalizations.

While exposure to heat may increase the risk of intussusception through mechanisms such as alterations in dietary intake and intestinal motility, no nationwide studies have investigated the association between daily heat exposure and intussusception in children. The study found the association between higher daily mean temperatures and an increased risk of hospitalization for intussusception. Both caregivers and healthcare providers should be aware of a potential increase in pediatric intussusception cases during warmer days, which may become even more critical as climate change results in more frequent and severe heat events.