Epidermal fatty-acid-binding protein: a new circulating biomarker associated with cardio-metabolic risk factors and carotid atherosclerosis

Aims Epidermal fatty-acid-binding protein (E-FABP) is highly homologous to adipocyte FABP (A-FABP), which mediates obesity-related metabolic syndrome (MetS), diabetes and atherosclerosis in animals. Combined deficiency of E-FABP and A-FABP protects against the MetS and atherosclerosis in mice. This study investigated the association of serum E-FABP with cardio-metabolic risk factors and carotid atherosclerosis in humans. Methods and results The presence of E-FABP in human plasma was detected by tandem mass spectrometry. Serum E-FABP levels, determined by an enzyme-linked immunosorbent assay in 479 Chinese subjects (age: 55.4 ± 13.5 years; M/F: 232/247), correlated positively ( P < 0.05 to <0.001, age-adjusted) with parameters of adiposity, adverse lipid profiles, serum insulin, A-FABP, and C-reactive protein levels and were higher in subjects with the MetS ( P < 0.001 vs. no MetS). The association of E-FABP with the MetS was independent of A-FABP. Furthermore, serum E-FABP correlated with carotid intima-media thickness (IMT; P < 0.001) and was independently associated with carotid IMT in men (adjusted P = 0.03). Conclusion E-FABP is a new circulating biomarker associated with increased cardio-metabolic risk. It may contribute to the development of the MetS and carotid atherosclerosis in humans, independent of the effect of A-FABP.