Exercise Training Program Found to Improve Cardiorespiratory Fitness in Older Adults with Advanced CKD

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A 12-month program of in-center aerobic and resistance exercise training was safe and improved physical functioning in adults aged ≥55 years with advanced chronic kidney disease (CKD) and medical comorbidity, according to results of a new study published in the American Journal of Kidney Diseases.

Among adults aged ≥55 with CKD stages G3b-4 and with a high level of medical comorbidity, 12 months of aerobic and resistance exercise training compared to health education control was found to be safe, feasible, and associated with improvements in submaximal gait and mobility.

CKD is common in older adults and is associated with impairment in cognition and physical function in this population. However, the safety and efficacy of long-term physical activity training in reducing physical function loss in these patients is unclear, according to study authors.

To gain insight into whether an exercise training program may improve cardiorespiratory fitness in adults with CKD but not on dialysis, researchers led by Daniel Weiner, MD, MS, of the Department of Medicine at Tufts Medical Center in Boston, Massachusetts, conducted a parallel-group randomized controlled trial of adults aged ≥55 years with CKD stage G3b-4 recruited from medical centers in Baltimore and Boston.

Participants in the experimental arm received 12 months of exercise training, which consisted of treadmill walking and strength training exercise. Training occurred 3-times a week at a dedicated research exercise center and was supervised by exercise specialists. Participants in the active comparator arm received 12 months of health education sessions on a range of topics, such as safe travel and age-appropriate preventative screenings.

According to the study abstract, the primary outcomes were cardiorespiratory fitness and submaximal gait at 6 and 12 months quantified by peak oxygen consumption on graded exercise treadmill test and distance walked on the 6-minute walk test, respectively. Secondary outcome measures were changes in lower extremity function, renal function, glycemia, blood pressure, and body mass index.

Findings

Among 99 (mean age, 68 years) adults included in the study, 62% were Black, 59% had diabetes, and 29% had coronary artery disease; mean eGFR was 33 mL/min/1.73m². Among adults who received exercise training, 59% of sessions were attended in the first 6 months and exercise was well tolerated without excess occurrence of adverse events, according to investigators.

Aerobic capacity at 6 months was higher among participants in the exercise arm compared to those in the control cohort (17.9 vs 15.9 ml/kg/min, p=.03), but differences were not sustained at 12 months.

The 6-minute walk distance improved more among adults who received exercise training than those who received the health education (adjusted differences: 98 ft, p=.02; p=.03 for treatment-by-time interaction). The exercise cohort also had greater improvements on the “get-up-and-go” test (p=.04), but not the short physical performance battery (p=.8), according to Weiner and colleagues.

Limitations included the fact that the planned sample size was not reached, and loss to follow-up and dropout were greater than researchers anticipated.

Reference: Weiner DE, Liu CK, Miao S, et al. Effect of long-term exercise training on physical performance and cardiorespiratory function in adults with CKD: A randomized controlled trial. Am J Kidney Dis. Published online August 5, 2022. doi:10.1053/j.ajkd.2022.06.008.