Abstract
KEY POINTS: Myosteatosis was associated with a higher risk of all-cause graft loss and mortality within the US cohort. Myosteatosis did not show an higher risk of death censored graft loss at both centers. Sarcopenia was not associated with a higher risk of all-cause graft loss or mortality. BACKGROUND: Sarcopenia and myosteatosis are indicators of abnormal body composition (BC). Computed tomography (CT) imaging has proven to be an accurate modality for BC quantification in kidney transplantation (KT). We tested whether pre-KT CT-based BC was associated with both all-cause graft loss (ACGL) and mortality among adult recipients from two centers (Johns Hopkins Hospital [JHH] and University Medical Center Groningen [UMCG]). METHODS: Patients who underwent a KT between 2003 and 2020 were followed for a median (interquartile range) follow-up of 6.4 (4.6–8.5) years at JHH and 6.3 (5.1–7.5) years at UMCG. Cox proportional hazard models were used to estimate the associations of BC with ACGL/mortality. Fine and Gray regression analysis was performed to assess the association between BC and death-censored graft loss. Before KT, 49% of recipients had sarcopenia and 66% had myosteatosis. RESULTS: In total, 608 patients were included from JHH ( N =294) and UMCG ( N =314). Sarcopenia was not associated with post-KT outcomes. Myosteatosis was associated with a higher risk of ACGL (adjusted hazard ratio, 1.78; 95% confidence interval, 1.08 to 2.93) and mortality (adjusted hazard ratio, 2.35; 95% confidence interval, 1.27 to 4.33) at JHH but showed no significant association at UMCG after adjusting for confounders. Myosteatosis did not show a significant association with death-censored graft loss at both centers. CONCLUSIONS: Myosteatosis ascertained from existing CT scans could help identify recipients at higher risk for ACGL who may benefit most from prehabilitation.