Physical Activity and Health-Related Quality of Life in Kidney Transplant Recipients: A Cross-Sectional Exploratory Study of Clinical and Inflammatory Parameters

Background/Objectives: Physical activity (PA) is a modifiable determinant of health and quality of life (QoL) in kidney transplant recipients (KTRs). However, associations between PA, health-related QoL (HRQoL), inflammation, and clinical factors in KTRs remain incompletely defined. The aim was to evaluate PA levels in KTRs and explore their associations with HRQoL, clinical characteristics, and biochemical and inflammatory markers. Methods: We conducted a cross-sectional study of 32 stable KTRs (56% male; mean age 54.5 ± 14.2 years). PA was assessed using the International Physical Activity Questionnaire and classified as low (<700 MET-min/week) or high (≥700 MET-min/week) according to IPAQ categorical scoring. HRQoL was evaluated using the SF-36. Associations with demographic, clinical, biochemical (including potassium), and inflammatory markers—including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic immune-inflammation index, and ferritin—were analyzed using multivariable binary logistic regression models. Results: Sixty-three percent of participants achieved high PA, which was associated with better physical functioning (78.8 vs. 58.3; p = 0.016), fewer emotional role limitations, younger age at transplantation, and preemptive transplantation or peritoneal dialysis. Active patients had modestly higher potassium levels (4.61 vs. 4.25 mmol/L; p = 0.041), a hypothesis-generating finding that should be interpreted cautiously. Inflammatory indices showed no significant associations. Conclusions: Although most KTRs achieved adequate PA levels, physical inactivity persisted in over one-third. Targeted strategies addressing HRQoL and clinical factors may support PA engagement after transplantation.