Sedentary behavior is more prevalent in the CKD population than in the non-CKD population. Independent of moderate/vigorous physical activities, sedentary activities are emerging as a risk factor for obesity, diabetes and mortality. There is a general consensus that sedentary activities must be decreased, but the critical unresolved questions are how much of the sedentary activities must be replaced and by which kind of activity. It is unlikely that moderate/ vigorous intensity (> 3 METs) activities could be a effective replacement for sedentary activities as most Americans do not even reach the current goals for these activities. Furthermore, assuming 16 awake hours/ day, achieving the currently recommended duration of moderate/ vigorous physical activities would account for only 2% of the total awake time (2.5 hours out of 112 awake hours/week). Therefore, decreasing sedentary activities must involve an increase in activities that are less intensive than moderate/ vigorous intensity physical activities. In other words, sedentary activities (< 1.5 METs) must be replaced by activities that are between 1.5 to 2.9 METs. As described in the preliminary data, our analyses of objectively measured physical activities in NHANES indicate that trade-off of each 2 min/hr. of sedentary duration with standing intensity (1.5 to 1.9 METs) type activities duration was not associated with survival benefit. However, a trade-off of each 2 min/hr. of sedentary duration with casual walking intensity (2 to 2.9 METs) type activities duration was associated with 41% lower hazard of death in the CKD subpopulation and 33% lower hazard of death in the entire cohort. Thus, interventions that replace sedentary activity with casual walking intensity activities might provide a survival benefit. This pilot study, titled `Sit Less, Interact, Move Moe (SLIMM) intervention for sedentary behavior in CKD' will test the hypothesis that the SLIMM intervention (with the goals of reducing sedentary duration by increasing casual walking duration and increasing breaks from sedentary activities) in CKD patients will be effective in decreasing sedentary duration and increasing casual walking duration. We will test this hypothesis in a 24 week RCT of 100 inactive, overweight/obese CKD participants randomized to either the SLIMM intervention or the standard of care. An accelerometer will be used to measure the posture and cadence (steps/min). Standardized protocols will be used to measure waist circumference, physical function and QOL and for sample collection, storage and assays of markers of inflammation and insulin resistance. Mixed effects models will be used for statistical analyses. The study is adequately powered. If the results of this pilot study show that replacing sedentary duration with casual walking duration is feasible, it will pave the way for larger RCTs targeting hard-endpoints in the high risk CKD population.
