Sedentary behavior as a modifiable risk factor for anemia and mortality in cancer survivors aged 55 years and older

Objective: This study aimed to explore the joint effect of sitting time on anemia status and its association with mortality among cancer patients aged 55 years and older in the United States. Methods: This cross-sectional study utilized two databases: the Global Burden of Disease (GBD) 2021 and National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2018. The burden of cancer attributable to low physical activity was assessed globally and in the United States using data from the GBD database. To evaluate the effects of sitting time in conjunction with anemia on mortality outcomes in cancer patients, we employed multivariate logistic regression, Cox regression analysis, and restricted cubic spline (RCS) analyses. Results: From 1990 to 2021, the number of cancer deaths associated with low physical activity increased both globally and in the United States. However, during the same period, the age-standardized death rate (ASDR) showed a slight downward trend. The study included a total of 2,581 adult cancer patients (aged ≥55 years) from the NHANES database. Compared to patients with shorter sitting durations, those with longer sitting durations exhibited a significantly higher incidence of anemia (OR = 1.98; 95% CI: 1.29-3.04). Additionally, a trend of increasing mortality was observed with longer sitting times (HR = 1.66; 95% CI: 1.24-2.21). In the joint analysis, prolonged sitting was associated with an elevated risk of mortality among cancer survivors with anemia (HR = 2.65; 95% CI: 1.60-4.38). Further analysis revealed that prolonged sitting has a more detrimental impact on gynecological cancers. Conclusion: This study reveals that from 1990 to 2021, global cancer mortality related to low physical activity has declined. Furthermore, the prolonged sedentary time in cancer patients is significantly associated with anemia, and their synergistic effect increases mortality risk. Sedentary behavior particularly increases the mortality risk of gynecological cancers. These findings suggest that clinical strategies should prioritize interventions tailored to different tumor types, particularly those managing sedentary behavior and anemia.