Exercise May Slow Kidney Disease Progression

Patients with stage 3 to 4 chronic kidney disease (CKD) assigned to an exercise/rehabilitation intervention have better maintenance of kidney function at one-year follow-up, according to preliminary research presented at Kidney Week 2014.

In a pilot study, consultant renal physiotherapist Sharlene A. Greenwood of King’s College London and colleagues evaluated an exercise training program for patients with predialysis CKD. Ten patients received the study intervention, which consisted of thrice-weekly exercise sessions at a gym setting in a community hospital. Another 10 patients received usual care.

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The exercise programs were individualized, accounting for patient choice and aiming for a combination of aerobic and resistance exercises. Aerobic exercise was predominantly performed on recumbent stationary exercise cycles, at an intensity corresponding to 80 percent heart rate reserve with maximum heart rate, based on incremental exercise testing. Resistance training was prescribed at 80 percent of one repetition maximum. The intervention also included an individual session with a senior renal physiotherapist for discussion of exercise and personal goals with use of a motivational interviewing approach.

Kidney function was assessed by comparing the rate of change in serum creatinine-based estimated GFR (eGFR) for each participant for 12 months before the study versus during the 12-month intervention period. Other outcomes of interest included pulse wave velocity, exercise capacity (VO2 peak), waist circumference, and body weight. Eight patients in the intervention group and 10 control individuals completed the study.

At the end of 12 months, patients assigned to the exercise/rehabilitation group had better-preserved kidney function. The mean difference in eGFR was 7.8 mL/min/1.73 m2/year, compared with the usual care group.

Exercise/rehabilitation was also associated with reduced body weight and improved exercise capacity. After adjustment for baseline differences, patients in the intervention group had a 5.6 kg reduction in body weight and a 7.1 cm reduction in waist circumference, with a 5.7 mL/kg/min increase in relative VO2 peak.

There was also a significant 2.30 m/second reduction in pulse wave velocity in the intervention group. The eGFR benefit was inversely correlated with the changes in pulse wave velocity and waist circumference.

Patients with stage 3 to 4 CKD have reduced exercise capacity, which may contribute to their risk of cardiovascular disease—the leading cause of death in CKD. Exercise training has the potential to preserve kidney function and improve cardiovascular risk factors in predialysis patients with CKD.

This pilot study suggests substantial benefits of an exercise/rehabilitation program for patients with stage 3 to 4 CKD. The benefits include a slower decline in kidney function after 12 months of exercise training, compared with usual care.

Together with improvements in exercise capacity and body weight, the exercise/rehabilitation program may be associated with improved quality of life in this group of patients. “Although small, our study suggests that long-term tailored exercise prescription with motivational interviewing is a feasible approach for exercising patients with progressive CKD, and sets the scene for a large multicenter study,” Greenwood said.