It is well known that sedentary behavior is associated with cardiovascular disease, obesity, hypertension, hypercholesterolemia, and diabetes, and is the fourth leading cause of death worldwide. It is also well established that lifestyle modifications are associated with lower risk of cardiovascular complications in the general population. Furthermore, more than 26 million individuals have CKD in the United States, and CKD patients have reduced cardiorespiratory fitness (CRF) compared with the general population and have an increased risk of mortality. Several studies have described impaired physical activity in ESRD and moderate CKD patients. The impact of lifestyle modification on outcomes in moderate CKD is not very clear and few studies have reported the adverse effects of physical inactivity in this category.
Howden et al performed an analysis of secondary outcomes of a randomized control trial where eighty-three patients received either a well-structured lifestyle intervention or usual care. The novel approach used an individualized exercise prescription developed by a nurse-practitioner-lead multidisciplinary team that included an exercise physiologist and psychologist. Patients with CKD stage 3 and 4 with one or more cardiovascular risk factor were included in this trial. Patients with symptomatic cardiovascular disease were among those excluded from the study. In the lifestyle intervention group, patients were expected to complete 150 minutes/week of moderate intensity aerobic and resistance exercise, starting with eight weeks of supervised exercise training, followed by 10 months of home-based training. 57% of participants averaged more than 150 minutes/week at 12 month compared to 64% at 6 month. The outcomes were assessed by METs, 6-minute walk test (6MWT) distance, timed Get-Up-and-Go test, grip strength, and weight and BP measures. There was no increase in serious adverse events related to the intervention.
The authors found that the intervention significantly increased METs (pre, 7.2±3.3; post, 9.7±3.6) and 6MWT distance (pre, 485±110 m; post, 539±82 m) at months 6 and 12 compared to baseline. On the other hand, the intervention did not improve the timed Get-Up-and-Go test or grip strength. The patients in the intervention group had an improvement in the body weight and BMI (pre, 32.5±6.7 kg/m2; post, 31.9±7.3 kg/m2). Physical activities improved initially in response to supervised exercise training, but levels returned to baseline levels at the 12 month follow up. This suggests that ongoing supervision had positive impact on physical activity levels in interventional group.
This study demonstrates that a combined model of supervised and home-based exercise training is efficacious and safe in patients with moderate CKD. While physicians should advise patients with moderate CKD to maintain a healthy lifestyle and exercise, it is unclear if the team approach used by Howden and colleagues is readily available for most current practices. This study is a welcome addition to our understanding of exercise and health in the CKD population, but should invite a larger randomized control trial evaluating whether such a novel design is cost effective on kidney function, cardiac risk factors, and overall survival.
Post written by Dr. Mahmoud Farhoud and edited by Dr. Abdo Asmar, AJKD Blog Advisory Board member