Improving Health Outcomes in Chronic Kidney Disease with Exercise

The kidneys are vital organs that remove waste products from the body, balance the body’s fluids, and release hormones that regulate blood pressure. Chronic kidney disease (CKD) affects more than 26 million Americans, and more than two-thirds of all CKD cases are caused by diabetes or high blood pressure. [1] High blood sugar and high blood pressure can overwork the kidneys, leading to their degeneration over time. Untreated CKD can result in end stage renal disease (ESRD), which is classified as a 90 percent loss of kidney function. Individuals with ESRD must either be treated with hemodialysis, a procedure where the blood is filtered to remove wastes, salts, and extra fluids, or receive a kidney transplant. While hemodialysis is the primary treatment for advanced kidney disease, exercise may also play a role in improved health outcomes.

Markers of inflammation are common in patients with kidney disease and on hemodialysis. Chronic inflammation is linked with muscle wasting and malnutrition, which can be contributing factors in cardiovascular mortality, the most common cause of death in patients with CKD.[3] Research suggests that daily activity over time helps control systemic inflammation. An observational study with 200 patients on hemodialysis found that physical activity levels were inversely associated with C-reactive protein (CRP) levels, a measure of inflammation in the body. [4] Similarly, another study on ESRD patients who wore an activity monitor found that CRP greater than 5mg/L was associated with lower energy expenditure.[5]

Several markers can be used to assess the physical fitness of patients on hemodialysis. Progress in these areas can improve a person’s response to hemodialysis and their overall quality of health. When patients included exercise in their daily routines, they showed improvements in peak VO2, knee extensor strength, 6 minute walk distance, and Beck Depression scores. Hemodialysis adequacy was lower in exercising subjects, meaning that a smaller amount of fluid needed to be removed during the procedure, causing less strain on the cardiovascular system. [6]

The Exercise & Sports Science Australia (ESSA) presented a position stand on exercise and chronic kidney disease, with many of the recommendations similar to those for healthy people. [7] It is recommended that CKD patients perform resistance training on two non-consecutive days a week and their heart rate (HR) should stay below 60% of their max HR. In conclusion, individuals with CKD or on hemodialysis may notice immediate benefits from physical activity.