Effect of Sit Less, Interact, Move More (SLIMM) Regimen on Patients With Chronic Kidney Disease (CKD)

More than one-third of U.S. adults (35.7%) are obese (body mass index (BMI) > 30 kg/m2). In 2008, medical costs associated with obesity were estimated at $147 billion. Furthermore, there is a graded association of BMI and the risk of end stage renal disease (ESRD). Indeed, increasing prevalence of CKD in the US population is partly explained by increasing BMI. Hence, as a public health policy, it is imperative that obesity be targeted in order to decrease the morbidity, mortality and the healthcare costs burden associated with CKD and ESRD.

Physical inactivity plays a major role in obesity. Volitional exercise (VE), which includes moderate to vigorous physical activities (MVPA) such as sports and fitness-related activities, and non-volitional exercise, which includes low to light intensity physical activity (PA) such as activities of daily living, fidgeting, spontaneous muscle contraction, and maintaining posture in non-recumbent positions, represent two different ends of the PA spectrum. The current national recommendations are focused on MVPA (30 minutes of moderate PA five times a week or 25 minutes of vigorous activities three times a week). However, the relative importance of low and light activities and MVPA has not been established. As described in the preliminary data, the analyses of objectively measured PA in National Health And Nutrition Examination Survey (NHANES) suggest that a larger amount of light intensity PA is strongly associated with lower odds of proteinuria, lower odds of CKD and a lower hazard of death at any given level of MVPA. Furthermore, there appears to be a threshold effect for MVPA with mortality that plateaus at about half of the currently recommended levels of MVPA. Since physical function in the CKD population is low, 30 minutes of moderate PA five times a week or 25 minutes of vigorous activities three times a week might induce fatigue and paradoxically reduce light intensity PA. On the other hand, a lower target of MVPA might improve adherence with MVPA as well as not decrease light PA. This pilot intervention study will test the efficacy, feasibility and tolerability of the SLIMM intervention. The results of this intervention will be later used to determine if targeting obesity via the SLIMM intervention will slow kidney disease progression.

DESIGN:

This is a pilot intervention study that will examine the feasibility of and adherence to the SLIMM intervention to increase levels of light physical activity

Baseline visit: Baseline PA data will be collected by accelerometer in the week following the screening visit. Participants will be instructed on the importance of physical activity, the recommendations of 150 min/wk of moderate PA, or 75 min/wk of vigorous PA, and be provided with examples of physical activities.

SLIMM Intervention: The goal of the SLIMM intervention is to increase the time spent on light activities (Light physical activity is defined as 500-2019 counts/minute). This intervention will only be completed by individuals in the CKD and non-CKD groups. At week 6 of the intervention participants will be instructed to perform 5 minutes of light activity for each 25 minutes of sitting time. At week 12, participants will be instructed to further increase their light activity to a goal of 10 minutes for each 20 minute of sitting time. Thus, the goal is to replace total sedentary time by increase in light activities by 15% in 6 weeks and 33% by the end of the intervention.

All participants will undergo standardized training on the SLIMM intervention by trained study personnel at the 6 week visit. Participants will initially be asked to perform 5 minutes of light activity for every 25 minutes spent seated. At the week 12 visit, participants will be asked to further increase their activity, by performing 10 minutes of light activity for every 20 minutes spent seated.

Training will be provided in one to one sessions and reinforced at the following visits. Accelerometry data and paper PA diary data collected during the week before the baseline visit will be reviewed with the participant to provide feedback and used for devising a customized plan on increasing light activity. Examples of how to increase light activities within their natural, free-living environment will be provided. For instance, if the majority of their day is spent working at a desk, they will be encouraged to stand and/or walk for 5 minutes for every 25 minutes spent sedentary during weeks 6-12, and 10 minutes of light activity for every 20 minutes spent sedentary for weeks 12-18. Participants will be asked to stand and/or walk during commercial breaks when they are watching television.