The Association of Daily Activity Levels and Estimated Kidney Function in Men and Women With Predialysis Chronic Kidney Disease

INTRODUCTION: Chronic kidney disease (CKD) is often accompanied by complications including poor physical activity level. However, only a few studies have objectively characterized physical activity levels in predialysis CKD. Our study sought to measure daily activity levels by accelerometry in individuals with CKD (stages III−V) and to determine the association between daily activity and kidney function. METHODS: We determined kidney function by means of the estimated glomerular filtration rate (eGFR) using the Modification of Diet and Renal Disease (MDRD) equation. Participants wore an accelerometer for 7 consecutive days, and we measured multiple physical activity outcomes including total daily activity, sedentary, light, and moderate−vigorous activity. Average durations and intensity of activity were determined according to stage of CKD. The association between kidney function and activity level was determined by regression analysis. RESULTS: We analyzed data from 110 individuals (60% men and 40% women) with stages III to V CKD. The mean age of our participants was 64 years, mean body mass index was 27.5 kg/m(2), and mean eGFR was 23.7 ± 1.2 ml/min/1.73 m(2). Our participants were primarily sedentary (mean duration of inactivity = 1152 ± 100 minutes per day; 79% of day). Light activity was performed 280 ± 99 minutes per day, and individuals participated in only 6 ± 9 minutes per day of moderate−vigorous activity. The eGFR did not predict physical activity level (P > 0.05 for all). DISCUSSION: Individuals with stages III to V CKD are sedentary, and do not meet the national recommendations of 150 minutes of moderate−vigorous activity per week. Further study is required to determine whether interventions to increase activity levels in patients with CKD are associated with improved health outcomes.