Independent assortment of GC gene polymorphism (rs2282679) and 25-hydroxyvitamin D levels in coronary artery disease.

Coronary artery disease (CAD) remains a major public health burden. Emerging research has suggested an association between vitamin D insufficiency and CAD. Vitamin D binding protein (VDBP) is the primary vitamin D carrier and many of its genetic polymorphisms are able to induce the expression of proteins with different affinities for the vitamin, which in turn might affect its serum levels and CAD incidence. One hundred and twelve male patients, aged between 35 and 50 years, with verified CAD and 109 age- and sex-matched controls were recruited. Genotyping was performed by the TaqMan allelic discrimination assay and plasma 25(OH)D levels were assessed by HPLC-UV. Serum parathyroid hormone (s-PTH) and VDBP levels were measured using ELISA. s-25(OH)D levels in CAD patients were significantly lower than in the controls, whereas s-PTH levels were significantly higher in the CAD patients than in the controls. There was no significant difference in the distribution of GC genotypes among both groups. s-25(OH)D showed a weak inverse correlation with s-PTH levels. Serum levels of vitamin D and PTH are highly correlated with CAD incidence. However, the s-VDBP level is associated neither with disease outcome nor with vitamin D status. The GC gene variant has no effect on 25(OH)D levels.