Relationships between hyperglycemia and the oxidative stress in type 2 diabetes

M Itoh; I Hiratsuka; J Hanashita; M Kimura; M Kondo; K Yoshida; Y Kuroyanagi; T Takayanagi; H Hirai; M Makino

A continuous glucose monitoring (CGM) provides a good tool to investigate the influence of glucose fluctuation on oxidative stress regarding as the pathogenesis of arteriosclerosis in type 2 diabetes (T2DM). The CGM can detect min-to-min glucose fluctuation under the daily activity and eating habit. We measured various indexes for oxidative stress and compared with the glycemic factors detected by the CGM.

Methods: T2DM (n=25) and healthy controls (n=14) were subjected to the CGM for 72 h and they were simultaneously measured blood levels of HbA1c, LDL, HDL, triglyceride, small dense (sd)- and oxidative (ox)- LDL, remnant-like particle lipoprotein (RLP), high-sensitivity (hs)-CRP, leptin, adiponectin, total free radical derived from reactive oxygen species (ROS), urinary output of 8-hydroxy-2′-deoxyguanosine (8-OHdG) and 15-isoprostane F2t (isoprostane).

Results: The mean and 2S.D. of the glucose in the control group were ranged from 73.2 to 148.3 mg/dl. Therefore, the hyperglycemic excursion was defined as the AUC above 140 mg/dl of glucose. The total ROS and urinary output of 8-OHdG and isoprostane were not different between the T2DM and control groups. However, the mean glucose and hyperglycemic excursion measured by CGM were correlated with total ROS (r²=0.191, r²=0.230, P<0.05) and urinary isoprostane (r²=0.187, r²=0.200, P<0.05). The glycemic indexes were not correlated with LDL, HDL, TG, RLP, sd-LDL, or ox-LDL. The glucose instability expressed as S.D. of the mean glucose and the combined percentages of hyper-plus hypoglycemia were not correlated with the oxidative stress indexes.

Discussion and conclusion: Hyperglycemia per se increased the production of oxidative stress detected by total ROS and urinary output of isoprostane and may accelerate the arteriosclerosis. The markers for oxidative stress might depend on its half-life and the exposed time for the hyperglycemia.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.

Endocrine Abstracts

P637