Pretransplant Psoas Muscle Cross-Sectional Area and Postkidney Transplant Outcomes

Background: Sarcopenia is associated with adverse outcomes in end-stage kidney disease. We evaluated if pretransplant sarcopenia affects posttransplant outcomes in kidney transplant (KT) recipients.

Methods: In this single-center retrospective study of adult patients with end-stage kidney disease, we analyzed the association between pre-KT psoas muscle cross-sectional area and critical posttransplant outcomes of decline in estimated glomerular filtration rate (eGFR), graft loss, rehospitalization, and mortality using Cox proportional hazard model adjusted for age, sex, and race.

Results: Pre-KT abdomen and pelvic computed tomography scans performed during evaluation for KT eligibility were available for 573 KT recipients. Of these, 465 KT recipients received kidney alone transplant, 71 received simultaneous liver kidney transplant (SLK), and 37 received simultaneous pancreas kidney transplant (SPK). Patients were 49 (SD, 13) years old, 16% Black, and 60% men. For kidney alone transplant recipients, a higher psoas muscle cross-sectional area was associated with a shorter length of hospitalization (β coefficient = -0.003; 95% CI, -0.005 to -0.0007). Conversely, pre-KT psoas muscle cross-sectional area did not predict decline in eGFR, graft loss, mortality, or early rehospitalization. For SLK recipients, psoas muscle cross-sectional area did not predict any of the priori outcomes. For SPK recipients, higher pretransplant psoas muscle cross-sectional area predicted a longer length of hospitalization (β coefficient = 0.03; 95% CI, 0.01-0.05). There was no association between psoas muscle cross-sectional area and other outcomes assessed.

Conclusions: Pretransplant psoas muscle cross-sectional areas are not predictive of post-transplant decline in eGFR, graft loss, rehospitalization or mortality in kidney alone, SPK, or SLK transplants.