April M. Teague

The Acute and Residual Effect of a Single Exercise Session on Meal Glucose Tolerance in Sedentary Young Adults

The study goals were to (1) establish the variability in postprandial glucose control in healthy young people consuming a mixed meal and, then (2) determine the acute and residual impact of a single exercise bout on postprandial glucose control. In study 1, 18 people completed two similar mixed meal trials and an intravenous glucose tolerance test (IVGTT). There were strong test-retest correlations for the post-meal area under the curve (AUC) for glucose, insulin, and Cpeptide (r = 0.73–0.83) and the Matsuda insulin sensitivity index (ISI, r = 0.76), and between meal and IVGTT-derived ISI (r = 0.83). In study 2, 11 untrained young adults completed 3 trials. One trial (No Ex) was completed after refraining from vigorous activity for ≥3 days. On the other 2 trials, a 45-min aerobic exercise bout was performed either 17-hours (Prior Day Ex) or 1-hour (Same Day Ex) before consuming the test meal. Compared to No Ex and Prior Day Ex, which did not differ from one another, there were lower AUCs on the Same Day Ex trial for glucose (6%), insulin (20%) and C-peptide (14%). Thus, a single moderate intensity exercise session can acutely improve glycemic control but the effect is modest and short-lived.

Associations between human breast milk hormones and adipocytokines and infant growth and body composition in the first 6 months of life

Much is to be learnt about human breast milk (HBM).

Postprandial improvement in insulin sensitivity after a single exercise session in adolescents with low aerobic fitness and physical activity.

The purpose of this study was to determine the acute and residual impact of a single exercise bout on meal glucose control in adolescents with habitually low physical activity. Twelve adolescents (seven females/five males, 14 ± 2 yr) completed three trials. One trial [No Exercise (No Ex)] was completed after refraining from vigorous activity for ≥3 d. On the other two trials, a 45‐min aerobic exercise bout at 75% peak heart rate was performed either 17‐h Prior Day Exercise (Prior Day Ex) trial or 1‐h Same Day Exercise (Same Day Ex) trial before consuming the test meal (2803 kJ, 45/40/15% energy as carbohydrate/fat/protein, respectively). Compared to No Ex, insulin sensitivity (SI) (minimal model analysis) was increased by 45% (p < 0.03) and 78% (p < 0.01) on the Prior Day Ex and Same Day Ex trials, respectively. This improvement in glucose control was supported by corresponding reductions in the net area under the curve for glucose, insulin, and c‐peptide, although there was no change in postprandial suppression of fatty acids. These results show that SI is improved with a single bout of moderate intensity exercise in adolescents with habitually low physical activity and that the residual beneficial effect of exercise lasts at least 17 h. This finding highlights the plasticity of exercise responses in youth and the importance of daily exercise for metabolic health.

Cord blood adipokines, neonatal anthropometrics and postnatal growth in offspring of Hispanic and Native American women with diabetes mellitus

BackgroundOffspring of women with diabetes mellitus (DM) during pregnancy have a risk of developing metabolic disease in adulthood greater than that conferred by genetics alone. The mechanisms responsible are unknown, but likely involve fetal exposure to the in utero milieu, including glucose and circulating adipokines. The purpose of this study was to assess the impact of maternal DM on fetal adipokines and anthropometry in infants of Hispanic and Native American women.MethodsWe conducted a prospective study of offspring of mothers with normoglycemia (Con-O; nu2009=u200979) or type 2 or gestational DM (DM-O; nu2009=u200945) pregnancies. Infant anthropometrics were measured at birth and 1-month of age. Cord leptin, high-molecular-weight adiponectin (HMWA), pigment epithelium-derived factor (PEDF) and C-peptide were measured by ELISA. Differences between groups were assessed using the Generalized Linear Model framework. Correlations were calculated as standardized regression coefficients and adjusted for significant covariates.ResultsDM-O were heavier at birth than Con-O (3.7 ± 0.6 vs. 3.4 ± 0.4xa0kg, pu2009=u20090.024), but sum of skinfolds (SSF) were not different. At 1-month, there was no difference in weight, SSF or % body fat or postnatal growth between groups. Leptin was higher in DM-O (20.1 ± 14.9 vs. 9.5 ± 9.9xa0ng/ml in Con-O, pu2009<u20090.0001). Leptin was positively associated with birth weight (pu2009=u20090.0007) and SSF (pu2009=u20090.002) in Con-O and with maternal hemoglobin A1c in both groups (Con-O, pu2009=u20090.023; DM-O, pu2009=u20090.006). PEDF was positively associated with birth weight in all infants (pu2009=u20090.004). Leptin was positively associated with PEDF in both groups, with a stronger correlation in DM-O (pu2009=u20090.009). At 1-month, HMWA was positively associated with body weight (pu2009=u20090.004), SSF (pu2009=u20090.025) and % body fat (pu2009=u20090.004) across the cohort.ConclusionsMaternal DM results in fetal hyperleptinemia independent of adiposity. HMWA appears to influence postnatal growth. Thus, in utero exposure to DM imparts hormonal differences on infants even without aberrant growth.

Oxidized HDL and LDL in adolescents with type 2 diabetes compared to normal weight and obese peers.

OBJECTIVEnObesity and type 2 diabetes mellitus (T2DM) are associated with oxidative stress. Oxidative damage of high-density lipoprotein (oxHDL) leads to a dysfunctional molecule, potentially a mediator and/or marker of cardiometabolic disease. We tested the hypothesis that circulating concentration of oxHDL is higher in obese (Ob) or T2DM adolescents compared to normal-weight (NW) peers.nnnMETHODSnIn 37 NW, 38 Ob, and 42 T2DM adolescents, ages 11-18 y, fasting concentrations of HDL and LDL cholesterol, oxHDL, oxidized low-density lipoprotein (oxLDL), and myeloperoxidase (MPO) were measured.nnnRESULTSnCompared to the NW group, oxHDL in the Ob group was not different, but was 65% higher (p < 0.01) in the T2DM group. Within the T2DM group oxHDL was higher in boys than in girls, but this sex difference was not evident in NW or Ob groups. OxLDL was 23% higher in Ob (p = 0.02), and 56% higher in T2DM (p < 0.01) versus NW and did not differ between boys and girls. MPO was not different between NW and Ob but was 88% (p < 0.02) higher in T2DM compared to NW. Contrary to our hypothesis MPO and insulin resistance (HOMA-IR) were not correlated with oxHDL. OxHDL was positively associated with oxLDL and lean body mass while oxLDL was positively associated with apolipoprotein B, triglycerides, HOMA-IR and trunk fat.nnnCONCLUSIONSnThe higher concentrations of oxHDL and oxLDL, along with higher MPO in children with T2DM reflect higher oxidative stress compared with obesity alone and potentially increased cardiovascular disease risk in youth with T2DM.

Pigment epithelium-derived factor (PEDF) varies with body composition and insulin resistance in healthy young people.

CONTEXTnPigment epithelium-derived factor (PEDF) was recently implicated as a metabolic regulatory protein because plasma concentration was increased in obese or insulin resistant adults. To our knowledge, circulating PEDF values in children have not been reported. Because PEDF is a predictor of metabolic health in adults, it may have a similar impact on metabolic profiles in children.nnnOBJECTIVEnThe objective of the study was to determine whether PEDF in normal-weight (NW) and overweight/obese (OW) children and young adults varies with age, sex, or body composition or is associated with clinical markers of metabolic disease.nnnSETTINGnVolunteers were tested at the University of Oklahoma Health Sciences Center.nnnPARTICIPANTSnNinety-one NW (8-30 yr old) and 105 OW (8-35 yr old) males and females participated in the study.nnnMAIN OUTCOME MEASURESnBody composition, blood pressure, arterial compliance, fasting plasma PEDF, glucose, insulin, (used for homeostasis model assessment of insulin resistance), triglycerides, cholesterol (total, low density lipoprotein, and high density lipoprotein), and C-reactive protein.nnnRESULTSnPEDF was 60% higher in the OW vs. NW participants but did not differ between males and females. PEDF was positively correlated with body mass, body mass index, fat and lean mass, fasting insulin, and homeostasis model assessment of insulin resistance in both the NW and OW groups. Multiple regression models revealed that fat and lean mass were significant predictors of circulating PEDF levels independent of age, sex, and body mass index category.nnnCONCLUSIONSnPlasma PEDF is elevated in OW youth and is positively associated with insulin resistance. These findings suggest that PEDF may play a role in the development of cardiometabolic dysfunction in youth.

Monitored Daily Ambulatory Activity, Inflammation, and Oxidative Stress in Patients With Claudication:

We determined the association between daily ambulatory activity and markers of inflammation and oxidative stress in patients with peripheral artery disease (PAD) and claudication. Patients with PAD (n = 134) limited by claudication were studied. Patients took 3275 ± 1743 daily strides for 273 ± 112 minutes each day, and their average daily cadence was 11.7 ± 2.7 strides/min. High-sensitivity C-reactive protein was significantly and negatively associated with the total number of daily strides (P < .001), total daily ambulatory time (P < .01), peak activity index (P < .01), daily average cadence (P < .05), and the maximum cadences for 60 minutes (P < .05), 30 minutes (P < .05), 20 minutes (P < .05), and 5 minutes (P < .01). Oxidized low-density lipoprotein and soluble vascular cell adhesion molecule 1 were not significantly associated with any of the ambulatory measures (P > .05). We conclude that higher levels of community-based, daily ambulatory activity are associated with lower levels of inflammation but are not associated with markers of oxidative stress.

Glycemic Variability Is Associated with Markers of Vascular Stress in Adolescents

OBJECTIVESnWe 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).nnnSTUDY DESIGNnA group of 13- to 21-year-olds (healthy weightxa0=xa012, healthy obesexa0=xa010, T2DMxa0=xa012) wore a continuous glucose monitor and step activity monitor for 5xa0days.nnnRESULTSnPhysical activity was similar among groups (6551xa0±xa0401 steps/d), but aerobic fitness (peak rate of oxygen consumption) was lower (Pxa0<xa0.05) in T2DM (15.6xa0±xa01.8xa0mL/kg/min) than either healthy weight (26.2xa0±xa02.2) or healthy obese (24.4xa0±xa02.5). MAGE (mg/dL) was higher (Pxa0<xa0.01) in T2DM (82xa0±xa010) vs healthy obese (33xa0±xa03) and healthy weight (30xa0±xa03). Average glucose followed a similar pattern as MAGE. Oxidized low density lipoprotein was higher (Pxa0<xa0.05) in T2DM (70.3xa0±xa05.0 U/L) and healthy obese (58.1xa0±xa03.8) than healthy weight (48.4xa0±xa02) and positively correlated with MAGE (rxa0=xa00.77). Other stress markers that were both elevated in T2DM and correlated with MAGE included E-selectin (rxa0=xa00.50), intercellular adhesion molecule 1 (rxa0=xa00.35), and C-reactive protein (rxa0=xa00.52); soluble receptor for advanced glycosylation end product was lower in T2DM and inversely correlated with MAGE (rxa0=xa0-0.38).nnnCONCLUSIONSnMAGE 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.

Effect of obesity and type 2 diabetes, and glucose ingestion on circulating spexin concentration in adolescents

Spexin is a novel peptide that has been reported to be down regulated in obese adults and children and in normoglycemic adults following glucose ingestion. Spexin may therefore have a role in metabolic regulation. The purpose of the current study was to determine the effect of obesity and type 2 diabetes (T2DM), and the effect of glucose ingestion on circulating spexin concentration in adolescents. Boys and girls (mean age 16 years old) classified as healthy normal weight (NW, n = 22), obese (Ob, n = 10), or obese with T2DM (n = 12) completed measurements of body composition, blood pressure, cardiorespiratory fitness, and blood concentrations of glucose, insulin, and lipids. The median fasting serum spexin concentration did not differ between groups (NW: 0.35; Ob: 0.38, T2DM: 0.34 ng/mL, respectively). In 10 NW participants who completed a standard oral glucose tolerance test, spexin concentration was unchanged at 30 and 120 minutes relative to the fasting baseline. Finally, spexin was not significantly correlated with any of the body composition, fitness, or blood biochemical measurements. These data do not support the proposed role of spexin as a metabolic regulator or biomarker of glucose control in adolescents.

Influence of gestational diabetes mellitus on human umbilical vein endothelial cell miRNA

We aimed to identify miRNAs whose expression levels in fetal tissues are altered by exposure to a diabetic milieu and elucidate the impact on target protein expression. Gestational diabetes mellitus (GDM) affects both immediate and future disease risk in the offspring. We hypothesized that GDM alters miRNA expression in human umbilical vein endothelial cells (HUVECs) that may influence metabolic processes. A cross-sectional design compared differences in miRNA expression in HUVECs and target protein abundance in placentae between infants of women with GDM (IGDM) and infants born to normoglycaemic controls. miRNAs were identified using microarray profiling and literature review and validated by quantitative PCR (qPCR). Inxa0vitro transfection studies explored the impact of the miRNA on target protein expression. Expression of seven miRNA species, miR-30c-5p, miR-452-5p, miR-126-3p, miR-130b-3p, miR-148a-3p, miR-let-7a-5p and miR-let-7g-5p, was higher in the HUVECs of IGDM. Abundance of the catalytic subunit of AMP-activated protein kinase α1 (AMPKα1) was decreased in the HUVECs and BeWo cells (transformed trophoblast cell line) transfected with miR-130b and miR-148a mimics. AMPKα1 expression was also decreased in placental tissues of IGDM. The expression of several miRNAs were altered by in utero exposure to DM in infants of women whose dysglycaemia was very well controlled by current standards. Decreased expression of AMPKα1 as a result of increased levels of miR-130b and miR-148a may potentially explain the decrease in fat oxidation we reported in infants at 1 month of age and, if persistent, may predispose offspring to future metabolic disease.