Obesity induced alterations in redox homeostasis and oxidative stress are present from an early age.

OBJECTIVES: Oxidative stress and inflammation have been postulated as underlying mechanisms for the development of obesity-related insulin resistance. This association however, remains elusive especially in childhood. We sought to investigate this relation by measuring oxidative stress and antioxidant response biomarkers, before and during an oral glucose tolerance test (OGTT), in different biological samples from obese children. SUBJECTS: 24 children were recruited for the study, (18 obese and 6 controls). After OGTT, the obese group was subdivided in two, according to whether or not carbohydrate metabolic impairment (Ob.IR+, Ob.IR-; respectively) was found. Different biomarkers were analyzed after fasting (T = 0) and during an OGTT (T = 60 and 120 min). Lipoperoxides were measured in plasma, erythrocytes, and urine; while advanced glycation end products were determined in plasma, and redox status (GSH/GSSG ratio) in erythrocytes. RESULTS: We found marked differences in the characterization of the oxidative status in urine and erythrocytes, and in the dynamics of the antioxidant response during OGTT. Specifically, Ob.IR+ children show increased oxidative stress, deficient antioxidant response and a significant imbalance in redox status, in comparison to controls and Ob.IR- children. CONCLUSION: Obese children with insulin resistance show increased levels of oxidative stress biomarkers, and a stunted antioxidant response to an OGTT leading to increased oxidative stress after a single glucose load, as detected in erythrocytes, but not in plasma. We propose erythrocytes as sensors of early and acute changes in oxidative stress associated with insulin resistance in childhood obesity. This is a pilot study, performed with a limited sample size, so data should be interpreted with caution until reproduced.

The Influence of Lipid and Proinflammatory Status on Maternal Uterine Blood Flow in Women With Late Onset Gestational Diabetes.

BACKGROUND: Gestational diabetes mellitus (GDM) is associated with increased proinflammatory cytokines and is also associated with adverse cardiovascular disease (CVD) outcomes later in life. We aim to evaluate the relationships between uterine arteries vascularization and endothelial dysfunction markers, proinflammatory cytokines, and glycemic and lipid profile in women with GDM. METHODS: Fifty pregnant women were recruited at the third trimester of pregnancy for a prospective cohort study. They were classified into 2 groups: control and GDM. Comparisons of maternal plasma concentrations of endothelial dysfunction markers (vascular cell adhesion molecule 1, intercellular adhesion molecule 1, and plasminogen activator inhibitor 1), proinflammatory cytokines and mediators (interleukin 6 [IL-6], tumor necrosis factor α, vascular endothelial growth factor, placental growth factor, leptin, leukocyte count, and C-reactive protein), lipid profile, glucose, and glycosylated hemoglobin levels were performed. Mean uterine arteries Doppler pulsatility index (PI) was calculated and the relationships between the variables and PI were also analyzed. RESULTS: Women with GDM showed higher proinflammatory cytokines, however, endothelial dysfunction markers were similar in both groups. In the diabetic group, significant correlations were found between the mean uterine arteries PI and maternal IL-6 ( r = .56, P = .01), triglycerides ( r = .49; P = .03), total cholesterol/high-density lipoprotein cholesterol (HDL-c) ratio ( r = .61; P = .006), glucose (r = .62, P = .005), and glycosylated hemoglobin ( r = .48; P = .03). A negative significant correlation between mean uterine arteries PI and HDLc ( r = -.58; P = .02) was also found. CONCLUSION: The proinflammatory status, hyperlipidemia, and metabolic control correlate with uterine blood flow velocity waveforms in women with gestational diabetes.