Glycemic control in adolescents with type 1 diabetes mellitus improves lipid serum levels and oxidative stress

Introduction: Atherosclerosis begins in childhood, and diabetes is a risk factor for coronary heart disease. Dyslipidemia is prevalent in children with type 1 diabetes mellitus (T1DM), with an association between elevated hemoglobin A1c (HbA1c), serum lipid levels, and oxidative stress. Our aim was to examine the effect of metabolic control on serum lipid levels and oxidative stress in adolescents with T1DM. Methods: Twenty-six adolescents (13 boys and 13 girls), aged 15.65 +/- 1.5 yr, with disease duration of 5.9 +/- 2.8 yr and average HbA1c 10.8 +/- 1.9% were assigned to intensive insulin therapy for 3 months. Comparisons for HbA1c, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein cholesterol, total triglycerides (TG), total cholesterol (TC), apolipoprotein AI, apolipoprotein AII, apolipoprotein B (ApoB), and thiobarbituric acid reactive substances (TBARS) were done between patients whose HbA1c improved by 0.5% or more (GR1) and the rest of the cohort (patients whose HbA1c improved by < 0.5%, did not change, or increased) (GR2). Results: ApoB (p = 0.047) and TBARS (p = 0.01) were significantly lower at the end of the study in GR1. In GR2, TC (p = 0.01) and LDL (p = 0.03) were significantly higher at study end. Overall, significant beneficial changes in TC (p = 0.006), TG (p = 0.04), LDL (p = 0.02), ApoB (p = 0.015), and oxidative stress (p = 0.001) were found in GR1 compared with GR2. Conclusions: We provide direct evidence for the beneficial effect of tight metabolic control on serum lipids and oxidative stress in adolescents with T1DM, indicating that tight metabolic control may reduce cardiovascular risk in these patients.