L WONG1,2, A KENT2, D LEE1,2, M ROBERTS1,2, L MCMAHON1,2
1Eastern Health Integrated Renal Service, Box Hill Hospital, 5 Arnold Street, Box Hill, Australia, 2Eastern Health Clinical School, Monash University, 5 Arnold Street, Box Hill, Australia
Aim: To determine the prevalence and predictors of sarcopenia and to assess its clinical significance in chronic kidney disease (CKD) patients subsequently receiving kidney transplantation (KT).
Background: Increasingly, patients exhibiting features of frailty are presenting for KT assessment. Frail individuals are more likely to have sarcopenia (reduced muscle mass, strength and function). Sarcopenia, as defined by radiological measures is associated with higher transplant waiting list mortality but studies on postoperative outcomes are lacking.
Methods: We retrospectively analysed 63 patients who underwent abdominal CT scanning within 2 years prior to KT between 2012-2020. Sarcopenia (as measured by cross-sectional skeletal muscle areas at L3 spinal level) and muscle attenuation (a radiological parameter inversely related to fat content) were assessed. Cut-off values used to define sarcopenia were <41cm2/m2 in women, <43cm2/m2 in men (body mass index [BMI] <25kg/m2) and <53cm2/m2 in men (BMI ≥25kg/m2), as previously published. Logistic regression and Cox proportional-hazards regression analyses were performed using R version 3.5.3.
Results: Median age was 57 years (IQR 48.5-63.5) and 71.4% (n=45) were male. Five patients had stage 4 CKD (range 15-20ml/min/1.73m2) and 58 had stage 5 CKD. Thirty-four patients (54.0%) had sarcopenia. Older age, females, low serum creatinine and low muscle attenuation were associated with sarcopenia. Only serum creatinine remained significant on multivariable analysis (p=0.01). In the dialysis-dependent subgroup (n=44), higher serum parathyroid hormone was independently predictive of sarcopenia following multivariable regression analysis (OR=1.06, p=0.03). Deceased donor transplant recipients (n=45) with sarcopenia demonstrated a greater risk of hospital readmission within 30-days of KT (adjusted HR=2.90, p=0.009).
Conclusions: Sarcopenia is highly prevalent in the pre-transplant CKD population and is associated with increased hospital readmission in the early post-transplant period.
Limy Wong is a Nephrology Fellow at Eastern Health in Melbourne. She graduated with First Class Honours in Medicine from the Royal College of Surgeons in Ireland and completed Nephrology specialist training in Ireland and the UK, gaining the Specialty Certificate in Nephrology from the Royal College of Physicians. During this time, she completed a Fellowship in Transplant Nephrology at Beaumont Hospital, the national renal transplant centre in Ireland. Following this, she completed a Wellcome Trust Clinical PhD Fellowship at the University of Cambridge with Prof Ken Smith studying the genetics of ANCA- associated vasculitis.