Serum AFBP levels are elevated in patients with nonalcoholic fatty liver disease

Adipocyte fatty acid-binding-protein (A-FABP), retinol-binding protein 4 (RBP4), and lipocalin-2 have been identified as adipokines that may link obesity, insulin resistance, and metabolic syndrome. Nonalcoholic fatty liver disease (NAFLD) is regarded as a manifestation of metabolic syndrome. We evaluated the relationship of A-FABP, RBP4, and lipocalin-2 to variables related to metabolic syndrome and NAFLD.

A total of 140 subjects (72 males and 68 females) were included in this study. Subjects were divided into two groups (NAFLD, n = 73 and normal, n = 67) based on the detection of a fatty liver by ultrasonography.

Serum A-FABP levels were higher in the NAFLD group than in the normal group (18.42 ± 7.24 ng/mL vs. 15.74 ± 7.02 ng/mL, p = 0.022). After adjusting for age and sex, we observed that body mass index (BMI), diastolic blood pressure, waist circumference, body fat percentage, triglycerides, and serum RBP4 levels were positively associated with serum A-FABP levels in all subjects. Multiple linear regression analysis revealed that systolic blood pressure, diastolic blood pressure, and serum RBP4 levels were independently associated with serum A-FABP levels. In logistic regression analysis, patients in the higher quartiles of A-FABP levels had higher odds ratios (OR) for the presence of NALFD than patients in the lower quartiles (OR: 3.56; 95% confident interval or CI: 1.25, 10.14).

We observed higher serum A-FABP levels in the NAFLD group than in the normal group. However, serum RBP4 and lipocalin-2 levels appeared to have different relationships with several variables related to metabolic syndrome and NAFLD, which contradict results of previous studies.