Сахарный диабет (Oct 2019)
Serum adipokine concentrations in patients with type 2 diabetes: the relationships with distribution, hypertrophy and vascularization of subcutaneous adipose tissue
Abstract
Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State Medical University, Novosibirsk, Russia BACKGROUND: Adipose tissue (AT) dysfunction plays an important role in metabolic disorders in obesity and type 2 diabetes. The role of distribution, hypertrophy and vascularization of AT in adipokine secretion disturbances remain to be clarified. AIMS: To determine the relationships between serum concentrations of adipokines and the mass and distribution of AT, diameter of adipocytes and vascularization of subcutaneous AT in patients with type 2 diabetes. MATERIALS AND METHODS: A total of 125 patients were examined, including 82 subjects with obesity. Thirty persons without diabetes and obesity, matched by sex and age, were acted as control. Concentrations of leptin, resistin, visfatin, adipsin and adiponectin in fasting serum were determined using multiplex analysis. Mass and distribution of AT was assessed by dual-energy X-ray absorptiometry. Samples of SAT were obtained from umbilical region using a knife biopsy in 25 patients and in 15 individuals who died in accidents. Blood and lymphatic vessels in SAT were revealed with immunohistochemistry, using antibody to CD-34 and podoplanin respectively. The volume and numerical density, ultrastructure of blood and lymphatic vessels, and mean diameter of subcutaneous adipocytes were evaluated. RESULTS: Patients with diabetes, as compared to control, had significantly higher levels of leptin, resistin, adipsin and visfatin (all p<0.001). Adiponectin showed no differences. Concentrations of leptin, resistin, visfatin, adipsin and adiponectin correlated positively with gynoid fat mass. Additionally, leptin and adipsinshowed positive correlations with truncal and central abdominal fat mass. Concentration of leptin, but not other adipokines, was associated with hypertrophy of subcutaneous adipocytes. A decrease in volumetric density of microvessels(р=0.01) and increase in volume and numerical density of lymphatic vessels (both р=0.02) was observed in subcutaneous AT from diabetic subjects. The swelling of cytoplasm, mitochondria, cisterns of granular endoplasmic reticulum and reduced content of micropinocytotic vesicles was revealed in lymphatic capillaries. Resistin and visfatin showed inverse associations with density of microvessels. CONCLUSION: Endocrine dysfunction of AT in patients with type 2 diabetes, manifested by elevation of serum concentrations of leptin, resistin, visfatin and adipsin, is associated with mass and distribution of AT, hypertrophy of subcutaneous adipocytes and vascularization abnormalities of subcutaneous AT.
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