Trends and predictions of colorectal cancer burden attributable to low physical activity in China and the USA, 1990–2021: Insights from the global burden of disease 2021 study

Colorectal cancer (CRC) constitutes a significant public health burden in both China and the United States of America (USA), with low physical activity (LPA) identified as a key modifiable risk factor. This study aimed to characterize temporal trends in CRC burden attributable to LPA in these 2 nations from 1990 to 2021. Using data from the 2021 global burden of disease database, age and sex-specific disparities in CRC burden attributed to LPA were evaluated in both countries. Trend analyses of age-standardized mortality rates and age-standardized disability-adjusted life year rates were performed using joinpoint regression. Decomposition analysis was applied to disentangle contributions from demographic aging, population growth, and epidemiological transitions. The age-period-cohort model was employed to quantify the independent effects of age, period, and birth cohort. Bayesian age-period-cohort modeling was utilized to project future CRC burden attributed to LPA through 2036. In 2021, LPA-attributable CRC mortality cases in China reached 16,698 (95% uncertainty interval: 10,065-24,626), exhibiting a 191.16% increase from 1990. The number of disability-adjusted life years attributed to LPA totaled 3,20,464 (95% uncertainty interval: 1,92,275-4,74,070), reflecting a 149.67% rise over the same period. Conversely, the USA reported more moderate increases of 18.26% in LPA-attributable CRC deaths and 20.28% in disability-adjusted life years. The age-period-cohort model revealed that the disease burden in both countries is shifting towards younger age groups. Further analysis of each state in the USA revealed that in 2021, the burden on low-income groups was heavier. The Bayesian age-period-cohort model predicts that the burden of CRC caused by LPA in the 2 countries will show a significant upward trend by 2036. As the burden of CRC caused by LPA becomes increasingly severe in China and the USA, there is an urgent need to raise public awareness about how physical activity can help prevent CRC and for policymakers to create targeted public health policies to lower this disease burden.