Correlation between the amplitude of glucose excursion and plasma 8-iso prostaglandin F2alpha level in subjects with different types of glucose regulation

Abstract

To investigate the effect of glucose excursion on oxidative stress that is expressed by plasma 8-iso prostaglandin F2alpha (8-iso) level. Continuous glucose monitor system (CGMS) was used to calculate the mean amplitude of glycemic excursion (MAGE), mean blood glucose (MBG) and its standard deviation (SDBG), mean 1 h preprandial glucose value (1 h-prePG) and 3 h post-prandial glucose value (3 h PPG) over 24 h period, area under the ROC curve when the blood glucose within 24 h > 5.6 mmol/L (AUC 5.6), mean of daily differences (MODD), and mean postprandial glucose excursion (MPPGE) on 33 individuals with normal glucose regulation (NGR), 25 subjects with impaired glucose regulation (IGR), and 25 patients with newly diagnosed type 2 diabetes mellitus (T2DM) for 3 days. Plasma 8-iso level was determined by EIA. The plasma 8-iso level of the T2DM patients was 230 ng/L, significantly higher than that of the subjects with IGR (199 ng/L, P < 0.05) and that of the NGR subjects (156 ng/L, P < 0.01). Patients with T2DM also had higher levels of glycated hemoglobin (HbA1c), MBG, SDBG, 1 h pre-PG and 3 h PPG, MAGE, and MODD than those of the NGR and IGR subjects (P < 0.05 or 0.01). The plasma 8-iso level and parameters of glucose excursion of the IGR subjects were all significantly higher than those of the NGR individuals (P < 0.05 or 0.01). Plasma 8-iso level was positively correlated with MAGE, MBG, SDBG, 1 h pre-PG, 3 h PPG, MODD, and HbA1c in all groups. Further analysis showed that the relationship between plasma 8-iso level and MAGE remained significant after adjustment for the other parameters of glucose excursion in multiple linear regression analysis (multiple R(2) = 0.55 for the model including MAGE). Standardized regression coefficients were 0.694 (P = 0.000) for MAGE. Glucose excursion exhibits a stronger triggering effect on oxidative stress than chronic sustained hyperglycemia in the subjects with IGR and T2DM.