The interrelationship between metabolic memory, glycemic variability, oxidative stress and microalbuminuria in type 1 diabetes

Patients and materials and methods Seventh-six T1D without clinical CDC and 22 healthy individuals were studied. MM was evaluated by glycated hemoglobin (HbA1c) of the last 3 yrs. GV: “short term” (STGV) by standard deviation (SD) of continuous glucose monitoring system (CGMS) over 3 consecutive days and “long term” (LTGV) by SD of the last 3 months on Accu Chek 360 diabetes management system. OS biomarkers (OSB) were estimated from 8 h overnight urinary excretion rates of 8-isoprostaglandin-F2a (ELISA, ALPCO-US), from plasma nitric oxide (NO) by chemiluminescence; plasma thiobarbituric acid reactive substances (TBARS) and erythrocytes reduced/oxidized glutathione (GSH/GSSH) by colorimetric assay (EnzyChrom GSH/GSSH AssayEGTT-100). HbA1c (HPLC; nv: 4.0-5.5%) and MA (imunoturbidimetric assay; nv <15 μg/min). Results T1D (age: 23.6±6.8 yrs, disease duration: 13.0±6.0 yrs., BMI: 23.8±3.6 Kg/m2 and HbA1c (mean±SD) of the last 3 yrs.: 8.9±1.5%) and controls (age: 25.8±3.9 yrs, HbA1c: 5.4±0.3% and BMI: 22.1±2.8 Kg/m2 were studied. STGV was higher in T1D than in controls (74.5±19.7 vs 10.8±1.7 mg/dL; p< 0.001) and had association with LTGV (rS: 0.36; p: 0.003), age (rS: -0.23; p: 0.037) and HbA1c (p: 0.001). LTGV (103±26.1 mg/dL) in T1D was associated with BMI (rS: 0.24; p: 0.047). NO was higher in T1D than controls: 115±104.1 vs 63.8±13.6 μM (p: 0.001) and in T1D was correlated with LTGV ( rS: 0.28 ; p: 0.036), MA (rS: 0.26; p: 0.049) and the HbA1c (mean of the last year; rS: 0.27; p: 0.042). TBARS was correlated to MA (rS: 0.32; p: 0.015). The GSH/GSSH and the 8-iso-PGF-2a didn’t show any correlation with the parameters studied.