Association between physical activity & sedentary time on frailty in adults with chronic kidney disease: Cross-sectional NHANES study.

Objective: A considerable percentage of individuals with chronic kidney disease (CKD) are reported to be frail. Lower physical activity and higher sedentary time are most consistently associated with frailty among the potentially alterable risk factors. Although the single effect of physical activity or sedentary time on suppressing frailty have been widely studied, whether physical activity can mitigate or counteract the detrimental consequences of higher sedentary time on frailty among CKD population has never been explored. This study aims to explore whether and to what extent the correlation between sedentary time and frailty was diminished by physical activity among CKD population.

Study Design And Setting: Data were acquired from the National Health and Nutrition Examination Survey (NHANES) 2007 to 2018 cycles. Frailty index was assessed using 49-item deficit model. Physical activity and sedentary time were measured using the Global Activity Questionnaire. Weighted binary logistic regression models, restricted cubic spline models and sensitivity analyses were performed to investigate the aforementioned relationship.

Results: The final sample included 2551 adults aged ≥20 years with CKD, which is represented a weighted number of 4.98 million noninstitutionalized US population. In the fully adjusted model, the group with low physical activity was 1.56 (95 % CI:1.19, 2.03) times more likely to develop frailty than the group with high physical activity and each unit of increase of sedentary time was associated with an 41 % increased risk of frailty (OR = 1.41, 95 % CI = 1.04-1.89). Our findings also indicated that engaging in 1240-6200 MET-min/week of high physical activity was associated with a decreased risk of frailty related to moderate-to-high sedentary time among CKD population (OR = 0.69, 95 % CI = 0.49-0.99, P = 0.044). In subgroup analyses, high physical activity was associated with a 0.43-fold (95%CI: 0.24, 0.77) decreased risk of moderate-to-high sedentary time associated with frailty in female groups and a significant modification effect of gender was uncovered (P = 0.024).

Conclusion: High physical activity was associated with a decreased risk of frailty related to moderate-to-high sedentary time in adults with CKD, especially in females subgroups.