BACKGROUND: Growth arrest-specific 6 (Gas6) is a vitamin K-dependent protein 
secreted by immune cells, endothelial cells, vascular smooth muscle cells, and 
adipocytes. Recent studies indicate that Gas6 and receptors of the TAM (Tyro3, 
Axl, and Mer) family may be involved in the pathogenesis of obesity, systemic 
inflammation, and insulin resistance. The aim of this study was to investigate 
the association between plasma Gas6 protein and the c.843 + 7G>A Gas6 
polymorphism in metabolic syndrome (MetS).
METHODS: Two hundred five adults (88 men and 117 women) were recruited in this 
study. Plasma Gas6 concentration, general, and biochemical data were measured. 
All subjects were genotyped for the c.843 + 7G>A Gas6 polymorphism.
RESULTS: Plasma Gas6 concentrations decreased in parallel with various MetS 
components in all groups (P = 0.017 for trend). Patients in the second and third 
tertiles of Gas6 level had higher high-density lipoprotein cholesterol (HDL-C) 
levels than those in the first tertile overall and in the female group. Plasma 
Gas6 levels were significantly positively correlated with HDL-C level and 
negatively with fasting glucose level in the female patients. The A allele and 
genotype AA in single nucleotide polymorphism c.843 + 7G>A were less frequent in 
the subjects with MetS compared to those without MetS.
CONCLUSIONS: Our results demonstrated a positive correlation between Gas6 
protein values and HDL-C and reinforce the association with fasting glucose. In 
addition, the presence of c.843 + 7G>A Gas6 polymorphisms, especially the AA 
genotype, had an association with MetS. The potential role of the Gas6/TAM 
system in MetS deserves further investigation.