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During the congress, E-Posters will be accessible to all participants on the congress website 24/7, as well as in the E-poster stations in the congress center.
Preparing your E-Poster
Please review the E-Poster format requirements carefully when preparing your E-Poster. Should your E-Poster not meet the mentioned requirements, it may not be displayed as described above.
E-Poster Submission Deadline
Please prepare and upload your E-Poster no later than March 14, 2026 11.59PM CET. After this date, you will no longer be able to prepare and upload your E-poster and it will not be displayed and accessible on the congress website.
Please follow the instructions below to input your abstract title.
Abstract titles should be brief and reflect the content of the abstract.
Acute kidney injury (AKI) is a severe condition characterized by a sudden decline in kidney function, with high mortality and healthcare costs. Although extreme ambient temperatures, particularly heatwaves, have been linked to increased AKI risk, the effects of both heat and cold exposure across different demographic groups remain unclear. This study examines the association between ambient temperatures and AKI emergency hospitalizations, with a focus on age and sex differences.
The daily number of emergency hospitalizations for AKI from 2011 to 2019 was extracted from the nationwide administrative claims database of acute-care hospitalizations across Japan (n = 119,027). A time-stratified case-crossover study incorporating conditional quasi-Poisson regression analysis was used to estimate region-specific relative risk (RR) of emergency hospitalization for AKI over lag 0–13 days. The pooled RR was subsequently derived using random-effects meta-analysis. Analyses were stratified by age (younger: 15–49 years, middle-aged: 50–64 years, and older: 65+ years) and sex.
The proportion of older adults in the study population was 77.7%, and males accounted for 63.6%. Median regional temperatures ranged from 9.9°C to 23.8°C, with maximum temperatures between 29.5°C and 32.6°C and minimum temperatures from –11.5°C to 9.2°C. The cumulative relative risk (RR) of AKI hospitalization was 2.18 (95% CI: 2.00–2.37) at the 99th percentile (extreme heat) and 1.19 (95% CI: 1.07–1.33) at the 1st percentile (extreme cold). The pooled lag–outcome association at the 1st percentile temperature showed the highest RR around lag days 2–3, gradually decreasing by lag day 6. At the 99th percentile, the highest RR was observed at lag 0, diminishing by lag day 3.
Stratified analyses by age and sex showed that extreme cold exposure increased the risk of AKI emergency hospitalizations among older females (RR 1.19; 95% CI: 1.00–1.43) and older males (RR 1.26; 95% CI: 1.08–1.48), with no significant associations observed in younger or middle-aged groups. For extreme heat exposure, females showed the highest RR in the older group (RR 1.85; 95% CI: 1.62–2.11), with weaker or no associations in the younger (RR 1.11; 95% CI: 0.68–1.82) and middle-aged groups (RR 0.95; 95% CI: 0.65–1.39). In contrast, males showed highest risk in the younger (RR 4.06; 95% CI 2.94–5.62) and middle-aged groups (RR 3.99; 95% CI 3.27–4.86), with the lowest but still significant risk observed among older males (RR 1.96; 95% CI 1.74–2.21).
Sensitivity analyses confirmed the robustness of the results across model specifications.
This nationwide study provides evidence of age- and sex-specific vulnerabilities to temperature-related AKI hospitalizations in Japan. Extreme heat was associated with the highest AKI risk among younger and middle-aged males. We also found that older females were significantly affected by heat exposure. Extreme cold was associated with increased AKI risk primarily among older adults of both sexes. These findings underscore the importance of incorporating age- and sex-specific approaches in both research and public health planning.
