Glycemic Variability Is Associated with Markers of Vascular Stress in Adolescents

Abstract

We used continuous glucose monitoring to test the hypothesis that mean amplitude of glycemic excursions (MAGE) is associated with circulating markers of oxidative and vascular stress in adolescents with habitually low physical activity classified as healthy weight, healthy obese, or obese with type 2 diabetes mellitus (T2DM). A group of 13- to 21-year-olds (healthy weight=12, healthy obese=10, T2DM=12) wore a continuous glucose monitor and step activity monitor for 5days. Physical activity was similar among groups (6551±401 steps/d), but aerobic fitness (peak rate of oxygen consumption) was lower (P<.05) in T2DM (15.6±1.8mL/kg/min) than either healthy weight (26.2±2.2) or healthy obese (24.4±2.5). MAGE (mg/dL) was higher (P<.01) in T2DM (82±10) vs healthy obese (33±3) and healthy weight (30±3). Average glucose followed a similar pattern as MAGE. Oxidized low density lipoprotein was higher (P<.05) in T2DM (70.3±5.0 U/L) and healthy obese (58.1±3.8) than healthy weight (48.4±2) and positively correlated with MAGE (r=0.77). Other stress markers that were both elevated in T2DM and correlated with MAGE included E-selectin (r=0.50), intercellular adhesion molecule 1 (r=0.35), and C-reactive protein (r=0.52); soluble receptor for advanced glycosylation end product was lower in T2DM and inversely correlated with MAGE (r=-0.38). MAGE is highest in obese youth with T2DM. The associations between MAGE and oxidative stress markers support the proposed contribution of glycemic variability to risk for future cardiovascular disease.