Preclinical diagnosis of diabetic nephropathy in children and adolescents with type 1 diabetes

Aim. To evaluate the diagnostic and prognostic value of hemodynamic characteristics and endothelial function (EF), viz. endothelium-dependent vasodilation (EDVD) and vasoconstriction (EDVC), during development of diabetic nephropathy (DN). Materials and methods. A total of 155 children and adolescents aged 9-17 years (residents of Volgograd) with type 1 diabetes mellitus (DM1) from 1 to 14 years in duration were examined at the Endocrinological Department of the Regional Childrens Clinical Hospital. The patients were divided into 3 groups depending on DM1 duration. EF and arteriolar tone (AT) were determined by the rheovasographic method. AT was calculated from vascular distension by a pulse wave based on tetrapolar rheovasography of the shoulder and its first derivative. Rheograms were registered using the Valenta software-hardware system. EF was evaluated in a reactive (working) hyperemia test with occlusion of blood vessels in the arm for 4 min followed by decompression; these procedures resulted in an abrupt acceleration of blood flow and endothelium response to shear stress by EDVD. EDVC was determined by occlusion of blood flow in the wrist area that caused its steady decline in the brachial artery and a decrease of its diameter suggesting enhanced vascular tone. Rheovasography was performed during occlusion. Results. Children with DM1 showed enhanced EDVC and impaired EDVD diagnosed before manifestation of microalbuminurea (MAU) characteristic of early DM1. Conclusion. Changes of EF determined from AT, EDVD and EDVC in children with DM1 before manifestation of microalbuminurea make it possible to identify patients at risk of vascular complications.