Association between temperature and global incidence of inflammatory bowel disease

There is a growing interest in the relationship between the global incidence of inflammatory bowel disease (IBD) and climate change. However, the precise relationship between long-term temperature change and IBD incidence on a global scale remains unclear.

The Global Burden of Disease (GBD) data set was employed, which comprises the age-standardized incidence rate (ASIR) of IBD from 1990 to 2021. The temperature change index was defined as the 32-year mean temperature combined with the metric of maximum temperature variability. A general linear mixed-effects regression model was employed to investigate the relationship between temperature variability and ASIR of IBD. Furthermore, we projected future changes in the incidence of associated IBD under four shared socioeconomic pathways (SSP: 126, 245, 370 and 585) for the period between 2020 and 2100.

Maximum temperature variability increased approximately threefold over the 32-year period from 1990 to 2021. We found that for each 1 °C increase in maximum temperature variability, the risk of IBD increases by 12.1%. Compared to the low-emissions scenario (SSP 126), we predict that global IBD incidence rates will change four times faster under the high-emissions climate change scenario (SSP 585) than under the low-emissions scenario (SSP 126) by 2100.

Our study suggested an association between global temperature variability and IBD incidence. Acknowledging the constraints of ecological data, this observed relationship indicates a need for further research to explore the underlying mechanisms and confirms the importance of considering climate change in the context of chronic disease prevention.