Inflammatory effects of blood leukocytes: association with vascular function in neuropeptide Y proline 7-genotyped type 2 diabetes patients.

OBJECTIVE

We investigated the associations of inflammatory blood cell activation with vascular parameters in patients with type 2 diabetes to elucidate the possible mechanisms of accelerated atherosclerosis observed in subjects with the Leucine 7 to Proline 7 polymorphism (Leu7Pro) in the neuropeptide Y (NPY).

METHODS

Our study included 31 Caucasian patients with type 2 diabetes; 12 of them had the Leu7Pro7 (heterozygous), and 19 had the Leu7Leu7 (wild type) genotype. Vascular parameters were determined by ultrasound methods. Leukocyte analyses were performed from blood samples using flow cytometry. NPY concentrations were determined in plasma.

RESULTS

The amount of platelet-granulocyte complexes was positively correlated with NPY concentration (p=0.008) and carotid intima-media thickness (p=0.035) in the Leu7Pro7 group. Interferon gamma (IFN-γ) expression in monocytes correlated negatively with brachial artery flow-mediated dilatation also in the Leu7Pro7 group (p=0.037). The expression of tissue factor on monocytes correlated negatively with brachial artery diameter in the Leu7Pro7 patients as well (p=0.019).

CONCLUSIONS

The results indicate significant associations between inflammatory cell activation in blood and vascular atherosclerosis in genetically prone subjects, and provide possible mechanistic information about the role of NPY and the Leu7Pro polymorphism in the development of atherosclerosis.