Objective: To determine the associations among dietary intake and inflammatory cytokines with physical activity, function, and performance in maintenance dialysis patients.
Design: Cross-sectional analysis of cohort study.
Setting: University-affiliated dialysis units, general clinical research center.
Subjects: Multiethnic cohort of maintenance hemodialysis patients.
Main Outcome Measures: Physical activity by accelerometry; physical performance by gait speed, stair climbing, and chair raising; physical functioning by the Medical Outcomes Study Short Form 36-item questionnaire subscale scores; and maximal and adjusted activity scores of human activity profile.
Results: Levels of inflammatory cytokines were uniformly high. Tumor necrosis factor-α was directly correlated with dietary protein and energy intake; no other cytokines were directly or inversely correlated with intake. Dietary intake was associated with physical activity, as expected, and not significantly associated with performance or function (with the exception of gait speed). There were no significant associations among inflammatory cytokines and physical activity, performance, or function.
Conclusion: Although dietary intake and inflammation may independently influence traditional proxies of nutritional status, this analysis provides no evidence for a link between cytokines and physical activity, performance, or function in hemodialysis patients. More research is required to understand the role of cytokines in protein energy malnutrition and the mechanisms of wasting and functional decline in the dialysis population.
