Exercise to Help Your Kidneys

Chronic kidney disease patients in lifestyle and exercise intervention program had improved cardiovascular and respiratory health

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) There are many benefits to exercise, but sometimes people may not get the exercise they need due to a chronic disease. For this reason, these people may need some guidance to better reap the benefits of exercise.

A recent study found that a combination of an exercise program and lifestyle changes led to improvements in the health of the heart, lungs and blood vessels of patients with chronic kidney disease.

The researchers also saw a weight reduction in patients who completed the exercise and lifestyle program, compared to patients receiving the standard care for chronic kidney disease.

The study indicates that even patients with chronic kidney disease may exercise without complications, and make improvements to their health and fitness.

"Talk to your doctor about starting an appropriate exercise program."

Erin Howden, PhD, with the Schools of Human Movement Studies and the Centre for Clinical Research Excellence at the University of Queensland in Australia, and colleagues conducted this study to see what effect exercise and lifestyle had on cardiorespiratory (heart and lung) fitness and cardiovascular (heart and blood vessels) risk factors in people with chronic kidney disease (CKD).

Additionally, the researchers wanted to see how exercise and lifestyle affected heart and blood vessel function in patients with CKD.

The researchers noted that patients with CKD tend to have poor cardiorespiratory fitness.

This study took place between February 2008 and March 2010. The researchers recruited 83 patients with stage 3 or 4 CKD (moderate to severe kidney disease). The patients were given an exercise stress test and echocardiogram before enrolling.

The patients were randomly assigned to either the control group, which received standard care, or the experimental group, which received lifestyle intervention.

Standard care was provided by a nephrologist, a doctor who specializes in kidney disease. These patients were referred to other healthcare providers as needed. The nephrologist recommended lifestyle changes, but did not provide specific information or education on the lifestyle changes to make.

The lifestyle intervention included standard care at a CKD clinic, as well as a lifestyle program which included care from a dietician, exercise physiologist, diabetes educator, psychologist and social worker.

The lifestyle intervention patients participated in aerobic and resistance exercise training for 12 months. The exercise program involved moderate intensity exercise for a total of 150 minutes each week. These patients started working out with an exercise physiologist in a gym for the first eight weeks. After eight weeks, the patients had a home-based program using resistance bands and an exercise ball.

The patients in the lifestyle intervention had four weeks of group behavior and lifestyle modification classes with a dietician and a psychologist.

Before starting the program, all study participants were tested for their maximal oxygen consumption, also called maximal aerobic capacity or VO2 max. This is the volume of oxygen an individual’s body can use during exercise. Maximal oxygen consumption is one method for testing a person’s physical fitness. Participants were retested 12 months later, after completing their assigned program.

The participants were also tested for function of the left ventricle of the heart before and after the program. There are four chambers of the heart, and the left ventricle is the chamber that pumps blood to the rest of the body. Function of the left ventricle was tested using an echocardiogram, which is a sonogram that takes pictures of the heart.

The researchers tested for stiffness of the arteries (blood vessel), body measurements and blood chemistry, such as blood sugar and cholesterol, before and after the program.

Out of the 83 patients who enrolled, 72 patients completed the program and follow-up. A total of 36 people in the standard care group and 36 in the lifestyle intervention group completed the study.

The researchers found that 10 percent of the patients had myocardial ischemia before starting the program. Myocardial ischemia is a disease of low blood supply to the heart, usually caused by plaque build-up in the arteries. Despite the disease, all of these patients were able to complete the study without any problems.

The study did not find any differences between the patient groups before the program began. After completing the program, however, the volume of oxygen patients were able to use increased on average approximately 3 milliliters per kilogram per minute.

The researchers found an average of about 4 pounds of weight loss after the lifestyle program compared to the patient's weight before starting the program. There was no change in weight among the group that received standard care.

There was no change in either group in blood pressure measurements or cholesterol levels after the program compared to before the program began.

There was a marked improvement in the function of the left heart ventricle in the diastolic, or relaxation, phase of the heart. There was no change in function of the left ventricle of the heart in the systolic, or contraction, phase.

The authors noted that the intervention did not change the stiffness of the arteries.

The authors concluded that exercise and lifestyle changes may improve the function of the heart and lungs for patients with chronic kidney disease. They also stated that proper exercise and lifestyle changes may also cause weight loss for these patients.

The authors noted some weaknesses of their study, including that they were not able to divide the parts of the lifestyle intervention (exercise, nutrition) to see the impact of each part.

They also did not observe the lifestyle intervention participants during exercise to figure out how much exercise they actually did. However, the changes in oxygen uptake indicate the participants exercised regularly.

The researchers also noted that they did not record changes in medication doses.

This study was published August 22 in the Clinical Journal of the American Society of Nephrology (CJASN).

The study was funded by the National Health and Medical Research Council-funded Centre for Clinical Research Excellence and the Department of Nephrology at the University of Queensland. The authors reported no conflict of interest.

Review Date: 
August 28, 2013
Last Updated:
September 3, 2013