Serum adipocyte fatty acid binding protein in liver transplant recipients and the metabolic syndrome

Background. Liver transplantation is often associated with metabolic derangements. Adipocyte fatty-acidbinding protein 4 (AFABP4) integrates inflammatory and metabolic responses. It has also been associated with metabolic syndrome in animal models and clinical studies in the general population. Aim. To determine the role of AFABP4 in post-transplant metabolic syndrome. Material and methods. Consecutive patients followed for at least 6 months after liver transplantation were tested for insulin resistance by homeostasis model assessment (HOMA). Serum levels of AFABP4 were tested by an enzyme-linked immunosorbent assay. Results. The study group included 76 patients (64.5% male, mean age 56.3 ± 12.4 years). Hypertension was present in 56.5%, hyperlipidemia in 69.7%, diabetes mellitus in 23.6%. Half of the patients met at least 3 criteria for metabolic syndrome. Serum AFABP4 levels (p < 0.0001), HOMA index ≥ 2.5 vs. < 2.5 (p < 0.0002) and BMI ≥ 30 vs. < 30 (p < 0.0006) were significantly higher in patients with metabolic syndrome. Within the metabolic syndrome subgroup, AFABP4 levels significantly correlated with age, aspartate aminotransaminase level, waist circumference, and HOMA index. High AFABP4 significantly increased the odds of acquiring metabolic syndrome (OR 1.04, 95% CI 1.007-1.074, p = 0.017). On multiple logistic regression analysis, independent predictors of high AFABP4 were cryptogenic liver disease, steroid administration, high HOMA index, and a high degree of fatty infiltration. Conclusion. Prevalence of metabolic syndrome is significantly higher in liver transplant recipients than in the general population. AFABP4 may serve as a circulating biomarker in the clinical prediction/diagnosis of metabolic syndrome in patients post-liver transplantation.