Relationship between oxidative stress and the first-phase of glucose-stimulated insulin secretion from pancreatic β cell in individuals with different glucose tolerance

The relationship between oxidative stress and the first-phase of pancreatic β cell insulin secretion in subjects with different statuses of glucose tolerance was explored. Fasting adiponectin, 8-hydroxydeoxyguanosin ( 8-OHdG), malondialdehyde ( MDA ), superoxide dismutase ( SOD ), insulin area under the curve ( AUC ) from 0 to 10 min, and AIR3-5 were measured. The levels of oxidative stress-related markers were elevated, the activities of superoxide dismutase,adiponectin, and first-phase of insulin secretion were reduced with the disease progression. MDA and 8-OHdG were negatively correlated with adiponectin, homeostasis model assessment β cell function index ( HOMA-β ),AUC ,and AIR3-5. SOD was positively correlated with adiponectin, HOMA-β, AUC, AIR3-5. The plasma 8-OHdG and SOD were independently associated with AIR3-5. Oxidative stress exerts a significant effect on the first phase of pancreatic β cell insulin secretion, which may contribute to the pathogenesis of type 2 diabetes. Key words: Diabetes mellitus, type 2;  Intravenous glucose tolerance test;  First-phase of insulin secretion; Oxidative stress;  A diponectin