Association of physical activity with graft failure and mortality: a nationwide cohort study of over 12 000 kidney transplant recipients

Background: Kidney transplantation improves survival and quality of life in end-stage kidney disease. Physical activity (PA), consistently associated with reduced mortality and cardiovascular risk in the general population, may represent a modifiable strategy to enhance transplant outcomes; yet, its impact on graft and patient survival has not been well-defined. Methods: This population-based cohort study was conducted using data from the Korean National Health Insurance Service. In total, 12 175 kidney transplant recipients who underwent national health screening within 4 years post-transplantation were included. PA was self-reported and quantified as metabolic equivalent task (MET) minutes per week. Participants were categorized as physically active if they engaged in either ≥3 sessions/week of vigorous-intensity or ≥5 sessions/week of moderate-intensity PA. The primary outcome was graft failure, and the secondary outcome was all-cause mortality. Cox regression models were used to assess the associations. Results: During a median follow-up of 7.4 years, 880 patients experienced graft failure, and 930 patients died. Physically active participants had significantly lower risks of graft failure (adjusted hazard ratio [HR]: 0.72, 95% confidence interval [CI]: 0.61–0.85) and all-cause mortality (adjusted HR, 0.85, 95% CI: 0.74–0.99) compared to inactive individuals. Achieving ≥450 MET-minutes per week – corresponding to the cohort median – was associated with improved outcomes compared to lower activity levels. Vigorous-intensity PA was associated with improved graft survival, whereas moderate-intensity PA did not show a significant association after full adjustment. Conclusions: Post-transplant PA was independently associated with improved graft and patient survival. Achieving ≥450 MET-minutes per week of regular PA may serve as a feasible and clinically meaningful target in kidney transplant care.