Risk Factors for Metabolic Syndrome After Liver Transplantation: A Systematic Review and Meta-analysis

Introduction: Metabolic syndrome is associated with increased risk of cardiovascular events, which contributes to the elevated mortality rate among liver transplant recipients. The objective of this systematic review and meta-analysis was to assess the prevalence and risk factors for metabolic syndrome after liver transplantation.

Methods: The databases Medline and Scopus were searched for observational studies evaluating prevalence and risk factors for metabolic syndrome after liver transplantation. Meta-analyses were performed based on odds ratios (ORs) from multivariable analyses. The Newcastle-Ottawa Scale was used for assessment of bias.

Results: The literature search generated 1815 records of which 16 articles were included comprising 3539 patients. The post-transplant prevalence of metabolic syndrome was 39%. Eight studies were eligible for meta-analyses, which showed that pre-transplant diabetes (OR=3.54, 95% confidence interval (CI): 2.51-4.98) and pre-transplant obesity (OR=2.44, 95% CI: 1.48-4.03) were risk factors for metabolic syndrome. Six out of seven studies reported that recipients with metabolic syndrome had a higher incidence of cardiovascular events. Four studies showed that survival was not affected by metabolic syndrome.

Conclusions: The prevalences of metabolic syndrome and new-onset metabolic syndrome were high after liver transplantation. Metabolic syndrome was associated with cardiovascular events, but not poorer survival. Patients with pre-transplant diabetes and -obesity are at high risk of metabolic syndrome and should be under careful surveillance in order to prevent, earlier diagnose, and treat metabolic syndrome and thereby limit the risk of cardiovascular events.