Associations of low muscle mass and myosteatosis with kidney transplant outcomes: a systematic review and meta-analysis.

Objective: Patients with end-stage renal disease are predisposed to low muscle mass and myosteatosis. This study aimed to investigate the predictive value of low muscle mass and myosteatosis, as assessed by computed tomography (CT), in predicting clinical outcomes following kidney transplantation.

Methods: A systematic search of PubMed, EMBASE, and the Cochrane Library was conducted to retrieve relevant English-language studies. Eligible studies reported on the associations of low muscle mass and myosteatosis, determined via CT scan, with clinical outcomes in kidney transplant recipients. The primary outcomes were patient and graft survival.

Results: A total of 13 studies involving 2,764 kidney transplant recipients were included. The pooled prevalence of low muscle mass was 28% (95% confidence interval [CI]: 0.16 - 0.40, I² = 98%), while that of myosteatosis was 24% (95% CI: 0.16 - 0.33, I² = 96%). Low muscle mass was significantly associated with an increased risk of patient mortality (hazard ratio [HR] = 2.08, 95% CI: 1.62 - 2.67, I² = 13%) and graft loss (HR = 1.43, 95% CI: 1.03 - 1.98, I² = 0%). Furthermore, low muscle mass was linked to an increased incidence of hospital readmissions within both 1 month (odds ratio [OR] = 2.05, 95% CI: 1.41 - 3.00, I² = 0%) and 3 months (OR = 1.78, 95% CI: 1.25 - 2.52, I² = 0%). Recipients with myosteatosis also demonstrated a significantly increased risk of mortality (HR = 1.82, 95% CI: 1.24 - 2.67, I² = 7%) and graft loss (HR = 1.99, 95% CI: 1.21 - 3.26, I² = 0%).

Conclusion: Low muscle mass and myosteatosis are prevalent in kidney transplant recipients and significantly impact prognosis. Comprehensive utilization of preoperative CT-derived muscle mass and density data may facilitate early risk stratification and inform clinical decision-making.