SAN DIEGO – A 12-week exercise program improved the physical capacity of patients with stage 3 and 4 chronic kidney disease, results from a single-center demonstrated.
The intervention also improved patient perceptions of general health, vitality, and physical functioning. "We believe that renal rehabilitation exercise programs can be integrated into standard chronic kidney disease treatment," Dr. Ana Paula Rossi, a nephrology fellow at Maine Medical Center, Portland, said at Kidney Week 2012.
Dr. Ana Paula Rossi
"We need longer follow-up and larger studies to determine if this will translate into decreased mortality rates and slow the progression of CKD," she said.
In a 12-week study conducted in 2011, Dr. Rossi and her associates randomized 48 patients with stage 3 and 4 CKD to usual care and 59 patients to an exercise intervention, which consisted of guided exercise at a cardiac rehabilitation facility two times per week for 3 months. Patients were encouraged to exercise an additional day per week on their own.
Exercise consisted of treadmill walking and/or stationary cycling. The duration was increased by 2-3 minutes per session, with the ultimate goal of 60 minutes of continuous exercise. Patients also did weight training with upper and lower extremity extensions and flexions with free weights. They started with one set of 10 repetitions per exercise, which was increased to a goal of three sets of 15 repetitions before the weight was increased. They also did stretching exercises.
Outcomes included the results of the 6-minute walk test (the number of feet walked per 6 minutes), the sit-to-stand test in which the patient is asked to sit and stand up 10 times (time reported is the percentage of age-predicted time), and the gait-speed test, a measurement of centimeters per second walked over a distance of 20 feet. To assess quality of life, the researchers administered the RAND 36-item Short Form Health Survey.
Patients with ongoing angina or transient ischemic attacks were excluded from the study, as were those with chronic lung disease resulting in significant shortness of breath or oxygen desaturation at rest, and those with lower-extremity amputation with no prosthesis or with an orthopedic disorder severely exacerbated by activity.
Patients in both groups were around 69 years old and had similar baseline reported levels of activity.
After the 12-week study period, the usual care group had no significant improvements in the three main outcomes. Patients in the exercise intervention group had significant improvements in the 6-minute walk test (19%, from 1,117 to 1,327 feet per 6 minutes; P = less than .0001) and in the sit-to-stand test (29%, from 68% to 97% of age predicted; P = .0004), but not in the gait-speed test (183 vs. 171 cm; P = .06).
Compared with their counterparts in the usual care group, patients in the intervention group reported significant improvements in energy (P = .01), physical functioning (P less than .01), and in general health (P = .03). Neither group experienced significant improvements in pain, emotional well-being, or in social functioning.
The study was funded by the Maine Medical Center Research Institute. Dr. Rossi said that she had no relevant financial conflicts to disclose.
The meeting was sponsored by the American Society of Nephrology.