Supervised Exercise Intervention and Overall Activity in CKD

Abstract

Introduction: Patients are often instructed to engage in multiple weekly sessions of exercise to increase physical activity. We aimed to determine whether assignment to a supervised exercise regimen increases overall weekly activity in individuals with chronic kidney disease (CKD). Methods: We performed a secondary analysis of a pilot randomized 2 Â 2 factorial design trial examining the effects of diet and exercise (10%À15% reduction in caloric intake, 3 supervised exercise sessions/wk, combined diet restriction/exercise, and control). Activity was measured as counts detected by accelerometer. Counts data were collected on all days for which an accelerometer was worn at baseline, month 2, and month 4 follow-up. The primary outcome was a relative change from baseline in log-transformed counts/min. Generalized estimating equations were used to compare the primary outcome in individuals in the exercise group and the nonexercise group. Results: We examined 111 individuals randomized to aerobic exercise or usual activity (n ¼ 48 in the exercise group and n ¼ 44 controls). The mean age was 57 years, 42% were female, and 28% were black. Median overall adherence over all time was 73%. Median (25th, 75th percentile) counts/min over nonsupervised exercise days at months 2 and 4 were 237.5 (6.5, 444.4) for controls and 250.9 (7.7, 529.8) for the exercise group (P ¼ 0.74). No difference was observed in the change in counts/min between the exercise and control groups over 3 time points (b [fold change], 0.96, 95% confidence interval [CI], 0.91, 1.02). Conclusion: Engaging in a supervised exercise program does not increase overall weekly physical activity in individuals with stage 3 to 4 CKD.

Comments on “Supervised Exercise Intervention and Overall Activity in CKD” by Pike et al.

“…We read with interest the study by Pike et al. 1 whereby patients with stages 3 to 4 chronic kidney disease were submitted to supervised exercise and calorie restriction and assessed for a hypothetical increase in overall weekly physical activity. Nevertheless, we call attention to possible baseline differences between groups.…”

The Effect of Nutrition and Exercise on Body Composition, Exercise Capacity, and Physical Functioning in Advanced CKD Patients

“…People with advanced chronic kidney disease (CKD) tend to be more physically inactive, have a sedentary lifestyle [ 1 , 39 ], and display impaired physical exercise capacity [ 40 , 41 ] and physical performance [ 40 , 42 ]. The degree of inactivity and impaired performance is heavily dependent on the severity of CKD [ 1 , 43 , 44 , 45 ].…”

The Authors Reply

“…Finally, to additionally alleviate concerns about differences in baseline activity in our study, we stratified the analyses by median baseline counts per minute (Table 3) and adjusted for baseline counts per minute in the analyses examining change in activity over 4 months. 2 Andrade et al 1 were concerned about the eligibility criteria of the study, whereby strict inclusion and exclusion criteria may hamper the generalizability of our findings to all patients with chronic kidney disease. The restriction to individuals with body mass index $25 kg/m 2 was implemented for safety concerns, to avoid potential development of protein energy wasting with dietary restriction.…”

“…We conducted a comparison of baseline values of sedentary time and light, moderate, and vigorous activity between the exercise and control group and reported the results in our supplementary text (Supplementary Table S2). 2 We additionally repeated our primary analyses after stratification by baseline percentage of sedentary time and included the results in our supplementary text (Supplementary Table S3). 2 No differences between the exercise and control groups in physical activity were seen at baseline, month 2, month 4, counts per minute over months 2 and 4, or change in counts per minute when stratified by percentage of sedentary time.…”

“…Finally, to additionally alleviate concerns about differences in baseline activity in our study, we stratified the analyses by median baseline counts per minute (Table 3) and adjusted for baseline counts per minute in the analyses examining change in activity over 4 months. 2 …”