FABP4 plasma concentrations are determined by acquired metabolic derangements rather than genetic determinants

Background and aims: Circulating FABP4 is strongly associated with metabolic and car- diovascular risk (CVR) and has been proposed as a new risk biomarker. Several FABP4 gene poly- morphisms have been associated with protein expression in vitro and metabolic and vascular alterations in vivo. The aim of this study is to evaluate the impact of FABP4 polymorphisms on FABP4 plasma levels and subclinical arteriosclerosis in patients with obesity, metabolic syn- drome (MS) or type 2 diabetes (T2DM). Methods and results: We studied 440 individuals with obesity, MS, T2DM or other cardiovascular risk conditions who attended the vascular medicine and metabolism unit of our hospital. Anam- nesis, physical examination and anthropometry data were recorded. Standard biochemical pa- rameters were determined. Plasma FABP4 concentrations were measured. Carotid intima- media thickness (cIMT) was assessed using ultrasonography. The following FABP4 gene single- nucleotide polymorphisms (SNPs) were analyzed: rs3834363, rs16909233, rs1054135, rs77878271, rs10808846 and rs8192688. None of the studied gene allele variants were hyper- represented in patients grouped according the presence of metabolic alterations nor were they associated with the FABP4 concentration. The FABP4 gene variants did not determine cIMT dif- ferences between the groups. In a multivariate analysis, gender and BMI, but not gene variants,