Physically active CKD patients have lower mortality rates than those who are inactive

Key takeaways:

• Lack of physical activity correlates with lower long-term survival among patients with chronic kidney disease.
• Promoting physical activity among patients may improve survival.

AUSTIN, Texas — Patients with chronic kidney disease who reported moderate to vigorous physical activity experienced a lower rate of mortality than patients who did not perform any physical activity, according to a poster presented here.

“This work was done under the umbrella of CDC’s Kidney Disease Surveillance System. The project director is Rajiv Saran MD, MS, MRCP, and co-PIs include Dr. Jennifer Bragg-Gresham, PhD, Dr. Brenda Gillespie, PhD, and Dr. Tiffany Veinot, PhD, all faculty at the University of Michigan,” Jenna Kiryakos, MPH, first author, from the division of nephrology in the department of internal medicine at the University of Michigan Kidney Epidemiology and Cost Center, told Healio. “We remain dedicated to CKD prevention and are interested in improving our understanding of the role of physical activity as a healthy lifestyle behavior in individuals with CKD. We know the benefits of exercise and physical activity on overall health in the general population, but since lifestyle changes are not systematically ‘prescribed’ in busy clinical practices, we decided to investigate this topic further among individuals with CKD, using 20 years of data from the National Health and Nutrition Examination Survey (NHANES, 1999-2018).”

Study design

This cross-sectional study included data of 48,048 survey respondents, with and those without CKD, who were at least 20 years of age. In the survey, respondents identified their physical activity habits as vigorous, moderate or inactive.

“Since our study is cross-sectional, one must be careful to not overinterpret the findings, as the role of health and physical limitations could be confounding factors in our findings,” Kiryakos said. 

Using a Cox regression model, researchers determined the mortality among participants after adjusting for age, sex, race/ethnicity, diabetes and hypertension.

Analyses revealed 28% of patients without CKD reported physical inactivity compared with the 44% of patients who did have CKD.

“Most surprising about our study was the finding that the mortality rate for physically active individuals with CKD was only 8% higher than individuals without CKD who were not physically active (P = .03), suggesting that there might be benefits to exercise in this patient population,” Kiryakos told Healio.

Overall, adults with CKD showed higher rates of mortality than those without CKD. Among patients with CKD who reported moderate or vigorous physical activity, data revealed a significantly lower rate of mortality than patients reporting no activity.

Potential solutions

To promote exercise among patients with CKD, Kiryakos told Healio that clinicians would likely need to consider “their patients’ socioeconomic and living situation, perspectives, physical limitations, other comorbid conditions, etc., before they make any specific physical activity-related recommendation.” 

Further, Kiryakos said clinicians can provide encouragement and education to patients to help motivate them to increase physical activity. 

“While our research focused on whether one was active in any capacity compared to being sedentary, future research should focus on whether varying intensity of activity (vigorous vs. moderate vs. inactive) affects mortality as well. Another consideration would be to investigate the role of [BMI] and/or dietary behaviors that might influence activity levels,” Kiryakos told Healio. “Keeping in mind sociocultural and socioeconomic factors, such as income, occupation, education, place of residence, etc., can expose disparities and other barriers that limit the ability to be active. Finally, randomized clinical trials or pragmatic quality improvement programs incorporating physical activity considerations alongside other evidence-based practices are required in this area to fully tap the potential of such an intervention.”

Editor's Note: On April 21, editors corrected quotes from the author for clarity. The Editors regret this error.