Prevalence and risk factors of sarcopenia in patients after kidney transplantation: An updated systematic review and meta-analysis

Background/objective: This study aimed to investigate the prevalence and risk factors of sarcopenia in patients who have undergone kidney transplantation (KT). Methods: A comprehensive search of PubMed, Cochrane Library, and Embase databases was conducted until Oct. 23, 2023. Sarcopenia was defined as the presence of low muscle mass, strength, and/or low physical performance. The outcomes of interest were the prevalence and risk factors associated with sarcopenia. Results: A total of 12 studies involving 1289 participants were included in quantitative analysis. The pooled result revealed an overall prevalence of sarcopenia in KT recipients of 15.8 % (95 % CI: 11.2 %–21.9 %, I² = 83.9 %). Subgroup analysis suggested that the variation in criteria for diagnosing sarcopenia (p < 0.001) and geographical regions (p < 0.001) accounted for the heterogeneity. Meta-regression analysis demonstrated that studies including patients with better preserved graft function, as assessed by estimated glomerular filtration rate, were associated with a lower prevalence of sarcopenia (β = −0.055, p = 0.032). The meta-analysis showed that KT patients with sarcopenia had a significantly lower body mass index (BMI) compared to those without (weighted mean difference: −4.457 kg/m², 95 % CI: −6.484 to −2.429). Conclusion: This meta-analysis found a 15.8 % prevalence of sarcopenia among KT recipients, with significant variations due to diagnostic criteria and geographical regions. Recipients with better graft function and higher body mass index were less likely to have sarcopenia. Longitudinal studies are needed to clarify the impact of sarcopenia in KT recipients.