8-hydroxy-2--deoxyguanosine and Hypoglycemia

Diabetic hyperglycemia is associated with increased production of reactive oxygen species (ROS). ROS reacts with DNA resulting in various products, such as 8-hydroxydeoxyguanosine (8-OHdG), that excrete in urine owing to DNA repair processes. Urinary 8-OHdG has been proposed as an indicator of oxidative damage to DNA. This study aimed to evaluate relationship between oxidative damage to DNA and protein glycation in patients with Type 1 diabetes. We measured urinary 8-OHdG level in diabetic patients and healthy subjects and discussed its relationship to glycated hemoglobin (HbA(1c)) and glycated serum protein (GSP) levels. Furthermore plasma malondialdehyde (MDA) level monitored as an important indicator of lipid peroxidation in diabetes. We studied 32 patients with Type 1 diabetes mellitus and compared the measured factors with those of 48 age-matched nondiabetic controls. GSP and MDA were measured bycolorimetric assay. Urinary 8-OHdG measurement was carried out using ELISA. In this study urinary 8-OHdG, HbA(1c), plasma MDA, and GSP levels were progressively higher in diabetics than in control subjects (P<0.05). Furthermore we found significant correlation between urinary 8-OHdG and HbA(1c) (P<0.05) in diabetic group. Correlation between fasting blood sugar and GSP were significant. We also found significant correlation between fasting blood sugar and MDA. This case-control study in young diabetic patients showed increased blood glucose and related metabolic disorders result in oxidative stress and oxidative damage to DNA and lipids. Furthermore oxidative damage to DNA is associated to glycemic control level, whereas lipid peroxidation level was not significantly correlated with glycemic control level. J. Clin. Lab. Anal. 24:72-76, 2010. (c) 2010 Wiley-Liss, Inc.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Blood Glucose; Creatinine; Deoxyguanosine; Diabetes Mellitus, Type 1; DNA Damage; Fasting; Female; Glycated Hemoglobin; Glycated Serum Albumin; Glycation End Products, Advanced; Glycosylation; Humans; Hypoglycemia; Lipid Peroxidation; Male; Malondialdehyde; Oxidative Stress; Serum Albumin; Young Adult

The effect of glucose excursions on oxidative stress is an important topic in diabetes research. We investigated this relationship by analyzing markers of oxidative stress and glycemic data from a continuous glucose monitoring system (CGMS) in 30 individuals with normal glucose regulation (NGR), 27 subjects with impaired glucose regulation (IGR), and 27 patients with newly diagnosed type 2 diabetes (T2DM). We compared the mean amplitude of glycemic excursion (MAGE), mean postprandial glucose excursion (MPPGE), and mean postprandial incremental area under the curve (IAUC) with plasma levels of oxidative stress markers 8-iso-PGF2α, 8-OH-dG, and protein carbonyl content in the study subjects. Patients with T2DM or IGR had significantly higher glucose excursions and plasma levels of oxidative stress markers compared to normal controls (P < 0.01 or 0.05). Multiple linear regression analyses showed significant relationships between MAGE and plasma 8-iso-PGF2α, and between MPPGE and plasma 8-OH-dG in patients with IGR or T2DM (P < 0.01 or 0.05). Furthermore, 2h-postprandial glucose level and IAUC were related to plasma protein carbonyl content in the study cohort including T2DM and IGR (P < 0.01). We demonstrate that glucose excursions in subjects with IGR and T2DM trigger the activation of oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Biomarkers; Blood Glucose; Cohort Studies; Deoxyguanosine; Diabetes Complications; Diabetes Mellitus, Type 2; Dinoprost; Female; Glucose Intolerance; Humans; Hyperglycemia; Hypoglycemia; Male; Middle Aged; Monitoring, Ambulatory; Oxidative Stress; Postprandial Period; Protein Carbonylation