The glucocorticoid receptor single-nucleotide polymorphism (SNP), N363S, has been reported to be associated with metabolic syndrome, Type 2 diabetes and cardiovascular disease. Our aim was to determine how the N363S SNP modifies glucocorticoid receptor signaling in a healthy population of individuals prior to the onset of disease. We examined the function of the N363S SNP in a cohort of subjects from the general population of North Carolina. Eighteen N363S heterozygous carriers and 36 non-carrier, control subjects were examined for clinical and biochemical parameters followed by a low dose dexamethasone suppression test to evaluate glucocorticoid responsiveness. Serum insulin measurements revealed that N363S carriers have higher levels of insulin, although not statistically significant, in comparison to controls. Glucocorticoid receptor protein levels evaluated in peripheral blood mononuclear cells from each clinical subject showed no difference between N363S and control. However, investigation of gene expression profiles in macrophages isolated from controls and N363S carriers using microarray, quantitative RT-PCR and NanoString analyses revealed that the N363S SNP had an altered profile in comparison to control. These changes in gene expression occurred in both the absence and presence of glucocorticoids. Thus, our observed difference in gene regulation between normal N363S SNP carriers and non-carrier controls may underlie the emergence of metabolic syndrome, Type 2 diabetes and cardiovascular disease associated with the N363S polymorphism.-