Low muscle mass and early hospital readmission post-kidney transplantation

Patients exhibiting features of frailty and sarcopenia increasingly are presenting for kidney transplantation (KT) assessment. Sarcopenia, when ascertained by radiological measures, is associated with a higher transplant waiting list mortality; but studies on post-operative outcomes are lacking. We aimed to determine the clinical significance of low muscle mass in chronic kidney disease (CKD) patients subsequently receiving KT.

We retrospectively analyzed 63 patients with Stage 4-5 CKD who, between 2012 and 2020, had undergone abdominal computed tomography (CT) scanning up to 2 years before KT. The degree of skeletal muscle loss was assessed using the total cross-sectional skeletal muscle area at the third lumbar vertebral level (L3). Cox proportional-hazards regression and Frailty models were used to identify risk factors for early hospital readmission post KT.

Thirty-four patients (54%) displayed low muscle mass, which was independently associated with a lower serum creatinine and phosphate, lower body mass index, lower mean muscle attenuation of the L3 cross-sectional area, and higher serum parathyroid hormone (for all p < 0.05). Deceased donor transplant recipients (n = 45) with low muscle mass demonstrated greater hospital readmissions within 30 days of KT [adjusted hazard ratio (HR) = 4.24, 95% CI 1.40-12.90, p = 0.01].

Low muscle mass is highly prevalent in the pre-transplant CKD population and is associated with increased hospital readmission in the early post-transplant period.