Influence of Sedentary Behavior and Physical Activity on Quality of Life and Survival Rate in Patients with Kidney Disease Undergoing Hemodialysis Treatment: A Cohort Study

Physical activity (PA) and sedentary behavior (SB) have emerged as modifiable factors in chronic kidney disease (CKD) patients undergoing hemodialysis (HD). The aim was to evaluate the association between PA, SB, quality of life, and mortality in patients with CKD undergoing HD. This prospective study included 167 patients who were assessed in 2023 and followed until September 2024. The long version of the IPAQ was used to assess PA and SB, and the Kidney Disease Quality of Life Short Form (KDQOL-SF 1.3) was used to evaluate health-related QoL. Survival was estimated using Kaplan–Meier curves, and a parsimonious Cox proportional hazards model. During the follow-up period, 15 patients (9.0%) died. Longer daily sitting time was independently associated with a higher mortality hazard (HR: 1.197; 95% CI: 1.026–1.396; p = 0.022), as was older age (HR: 1.055; 95% CI: 1.009–1.103; p = 0.019). MVPA was not significantly associated with mortality (HR: 1.217; 95% CI: 0.997–1.486; p = 0.054). The Active/Low SB profile showed the highest baseline QoL [median: 74.0 (IQR: 64.5–84.0)], whereas the Inactive/High SB profile showed the lowest QoL [median: 66.0 (IQR: 54.0–76.0)] and the highest mortality proportion (14.6%). However, mortality differences across the combined PA and SB profiles were not statistically significant and should be interpreted as exploratory. Baseline QoL differed significantly across profiles (p = 0.021). These findings identify prolonged sitting time as the main modifiable behavioral factor independently associated with all-cause mortality in patients undergoing HD, whereas MVPA was not independently associated with mortality. In contrast, physical activity and combined PA/SB profiles were more clearly related to health-related QoL, with the Active/Low SB profile showing the most favorable KDQOL-SF™ 1.3 scores. Therefore, reducing prolonged sedentary time may be particularly relevant to survival risk, while promoting appropriately tailored physical activity may contribute to better health-related QoL in this population.