Key Points

Physical exercise mitigates several kidney-related pathophysiological pathways, yet its effect on kidney function remains underexplored.This randomized clinical trial found that high-intensity interval training significantly reduced the risk of rapid eGFR decline in older adults.Physical exercise can preserve kidney function, benefiting public health and individual patient outcomes similar to other cardiovascular diseases.

Background

CKD is a growing global public health issue. Physical exercise mitigates several kidney-related pathophysiological pathways, yet its effect on kidney function remains underexplored. We investigated the dose-response effect of physical exercise on kidney function preservation in older adults.

Methods

We conducted a post hoc analysis of the Generation 100 Study, a 5-year open-label, randomized, parallel-arm clinical trial conducted from 2012 to 2018 in Trondheim, Norway. All inhabitants aged 70–77 years were invited (n=6966). Main exclusion criteria were dementia; severe, uncontrolled cardiovascular disease or hypertension; or conditions precluding exercise. The control group (n=385) received information on national physical activity recommendations. Intervention groups underwent supervised moderate-intensity continuous training (70% of peak heart rate) for 50 minutes (n=380) twice weekly for 5 years or high-intensity interval training (90% of peak heart rate) for 4 minutes ×4 (n=391) twice weekly for 5 years. The primary outcome was cystatin C–based rapid eGFR decline (>5 ml/min per 1.73 m2 per year).

Results

A total of 1156 participants were randomized, with median (interquartile range) age 72 (3) years and eGFR 95 (20) ml/min per 1.73 m2. Oxygen uptake increased by 1.8, 2.3, and 3.3 ml/kg per minutes in the control, moderate-intensity, and high-intensity groups, respectively. Rapid eGFR decline occurred in 117 (30%), 108 (28%), and 92 (23%) participants, respectively. Compared with controls, relative risk (RR) was 0.93 (95% confidence interval [CI], 0.75 to 1.16) for the moderate-intensity and 0.75 (95% CI, 0.59 to 0.95) for high-intensity groups, demonstrating a significant dose-response relationship (P for trend 0.02). In observational analyses, participants with decreasing moderate-to-vigorous intensity activity (>−20 min/wk) had RR 1.30 (95% CI, 0.93 to 1.83) for rapid eGFR decline, while those with increasing activity (>+20 min/wk) had RR 0.73 (95% CI, 0.53 to 0.99) compared with stable activity after adjusting for baseline age, sex, peak oxygen uptake, and eGFR.

Conclusions

High-intensity interval training significantly reduced the risk of rapid eGFR decline in older adults.

Clinical Trial registry name and registration number:

ClinicalTrials.gov: NCT01666340.