Increased physical activity was associated with a substantially lower risk for kidney function decline, with the strongest effects seen with higher frequencies and intensities of activity, according to a new longitudinal study.

“Increasing physical activity frequency was associated with a slower mean measured glomerular filtration rate (GFR) decline and a lower risk of accelerated measured GFR decline,” the authors reported in a study published in the Clinical Journal of the American Society of Nephrology.

“Promoting physical activity and reducing sedentary behavior, especially in general and aging populations, is a low-cost, high-impact strategy for preventing chronic kidney disease (CKD) development and its associated financial burden,” they added.

An 11-Year Analysis

Although physical activity has been linked to renoprotective effects in both the general population and individuals with CKD, much of this benefit has been attributed to improvements in cardiovascular health and related risk factors.

To assess whether physical activity independently helps prevent GFR decline in the general population, the first author Inger T.T. Enoksen, PhD, of the Metabolic and Renal Research Group, UiT The Arctic University of Norway in Tromsø, Norway, and colleagues analyzed data of 1837 individuals enrolled in the longitudinal Renal Iohexol Clearance Survey cohort. Participants did not have self-reported diabetes, cardiovascular disease, or kidney disease at baseline.

Kidney function was assessed with repeated GFR measurements over 11 years, using iohexol clearance, and baseline physical activity was evaluated using a validated questionnaire measuring frequency, intensity, and duration.

At baseline, 43% of participants met the World Health Organization (WHO) physical activity recommendations needed to achieve health benefits, defined as a minimum weekly exercise volume of at least 450 metabolic equivalents of task minutes.

Frequent Exercise Slows GFR Decline

Over the 11 years, the median annual decline in measured GFR was -1.06 mL/min/1.73 m² (interquartile range, -1.31 to -0.80).

Participants with a higher physical activity frequency had up to a 71% lower odds of accelerated GFR decline compared with inactive patients, after adjustment for baseline age, sex, BMI, smoking status, blood pressure medication use, systolic blood pressure, and fasting glucose.

Those who exercised more frequently and met the WHO physical activity recommendations had a significantly slower annual GFR decline before adjusting for smoking and alcohol consumption, with a clear dose-response trend observed as activity frequency increased (P = .001).

Among those engaging in daily physical activity, the annual rate of measured GFR decline was also significantly slower at 0.47 mL/min/1.73 m² (P = .006).

Adjustment for smoking and alcohol use attenuated the effects of exercise intensity, however, the effects of exercise frequency remained significant even after adjusting for those factors, including among those reporting exercising two to three times per week (P = .03) and daily (P = .05).

Notably, increases in physical activity duration were not significantly associated with changes in the mean GFR rate.

Sensitivity analyses using absolute GFR and GFR adjusted for an estimated total body water of 40 L showed consistent results. Similar associations were also observed among patients with comorbidities, including diabetes, cardiovascular disease, and hypertension.

The Upsides of Promoting Physical Activity

Taken together, the findings “could indicate that physical activity is beneficial for preserving GFR in a relatively healthy general population, potentially extending beyond effects mediated by these conditions,” the authors noted.

They noted that this was the first study examining associations between self-reported physical activity and longitudinal GFR changes using highly accurate GFR measurements in the general population.

Overall, the results suggest that “promoting increased physical activity and reduced sedentary behavior could serve as a global primary prevention strategy for CKD and GFR decline, even among those already physically active and without diabetes, cardiovascular disease, or hypertension,” the authors concluded.

The authors disclosed having no relevant financial relationships in the published study.