Supplementation with Bifidobacterium breve BR03 and B632 strains improved insulin sensitivity in children and adolescents with obesity in a cross-over, randomized double-blind placebo-controlled trial.

BACKGROUND & AIMS: Variations in gut microbiota might impact metabolism leading to body weight excess. We assessed the impact of a probiotic supplementation in pediatric obesity on weight, metabolic alterations, selected gut microbial groups, and functionality. METHODS: Cross-over, double-blind, randomized control trial (BIFI-OBESE trial; NCT03261466). 101 youths (6-18 years, Tanner stage ≥2) with obesity and insulin-resistance on diet were randomized to 2 × 109 CFU/AFU/day of Bifidobacterium breve BR03 (DSM 16604) and B. breve B632 (DSM 24706) (51) or placebo (50) for 8 weeks with a 4-weeks wash-out period. RESULTS: All subjects (M/F 54/47) completed the first 8 weeks, and 82 (M/F 43/39) the last part without adverse events. Mixed-effects models revealed a carry-over effect on many variables in the entire study, narrowing the analysis to the first 8 weeks before the wash-out periods. All subjects improved metabolic parameters, and decreased weight and Escherichia coli counts. Probiotics improved insulin sensitivity at fasting (QUICKI, 0.013 CI95%0.0-0.03) and during OGTT (ISI, 0.654 CI95%-0.11-1.41). Cytokines, GLP1, and target microbial counts did not vary. Of 25 SCFAs, acetic acid and acetic acid pentyl-ester relative abundance remained stable in the probiotics, while increased in the placebo (p < 0.02). A signature of five butanoic esters identified three clusters, one of them had better glucose responses during probiotics. CONCLUSION: An 8 weeks treatment with B. breve BR03 and B632 had beneficial effects on insulin sensitivity in youths with obesity. Microbiota functionality could influence metabolic answers to probiotics. Long-term studies to confirm and enrich our findings are justified. Tailored probiotic treatments could be an additional strategy for obesity. TRIAL REGISTRATION: NCT03261466.

Identification of Haptoglobin as a Readout of rhGH Therapy in GH Deficiency.

BACKGROUND: GH deficiency (GHD) is characterized by a cluster of cardiovascular risk factors and subtle inflammation. We aimed to demonstrate, through a proteomic approach, molecules directly modulated by GHD and involved in the inflammatory state. METHODS: Ten children with isolated GHD were studied before and after 1 year of treatment with rhGH and compared with 14 matched controls. A two-dimensional electrophoresis plasma proteomics analysis was performed at baseline and after GH treatment to identify the top molecules modulated by GH. In vitro studies on human hepatoma (HepG2) cells were performed to validate the data. RESULTS: Twelve of 20 proteomic spots were predicted to be isoforms α and ß of haptoglobin (Hp) and confirmed by liquid chromatography tandem mass spectrometry and Western immunoblot analyses. Hp levels were higher in patients with GHD than controls at baseline (P < 0.001) and were reduced following GH treatment (P < 0.01). In HepG2 cells, both GH and IGF-1 were able to downregulate IL-6-induced Hp secretion. Moreover, Hp secretion was restored in pegvisomant-treated HepG2 cells. CONCLUSIONS: Hp is a molecule acting in the inflammatory state of GHD and a possible biomarker for GH treatment. Nevertheless, the contribution of other factors and the molecular pathways involved in the GH downregulation of Hp remain to be clearly defined.

Circulating adipokines and metabolic setting in differentiated thyroid cancer.

The associative link relating insulin resistance (IR) and adipokines to the occurrence and phenotype of differentiated thyroid cancer (DTC) is unknown. The aim of this study was to evaluate the relationship between IR and adipokines in DTC patients, as compared with carriers of benign thyroid diseases (BTD) and healthy controls. This observational study enrolled 77 subjects phenotyped as DTC (N = 30), BTD (N = 27) and healthy subjects (N = 20). Each subject underwent preoperative analysis of anthropometric parameters, thyroid function and autoimmunity, insulin resistance (HOMA-IR) and levels of unacylated (UAG) and acylated ghrelin (AG), obestatin, leptin and adiponectin. Multivariate regression models were used to test the predictive role of metabolic correlates on thyroid phenotypes and DTC extension. The three groups showed similar age, gender distribution, smoking habit, BMI and thyroid parameters. Obestatin was significantly higher in DTC group compared to BTD (P < 0.05) and control subjects (P < 0.0001). DTC and BTD groups showed higher levels of UAG (P < 0.01) and AG (P < 0.05). Leptin levels were comparable between groups, whereas adiponectin levels were lower in DTC compared to BTD group (P < 0.0001) and controls (P < 0.01). In parallel, HOMA-IR was higher in DTC than BTD (P < 0.05) and control group (P < 0.01). Stepwise multivariable regression analysis showed that obestatin and UAG were independent predictors of DTC (P = 0.01 for both). In an analysis restricted to the DTC group, obestatin levels were associated with the absence of lymph node metastases (P < 0.05). Our results highlight a potential association between metabolic setting, circulating adipokines and thyroid cancer phenotype.

Intracoronary Des-Acyl Ghrelin Acutely Increases Cardiac Perfusion Through a Nitric Oxide-Related Mechanism in Female Anesthetized Pigs.

Des-acyl ghrelin (DAG), the most abundant form of ghrelin in humans, has been found to reduce arterial blood pressure and prevent cardiac and endothelial cell apoptosis. Despite this, data regarding its direct effect on cardiac function and coronary blood flow, as well as the related involvement of autonomic nervous system and nitric oxide (NO), are scarce. We therefore examined these issues using both in vivo and in vitro studies. In 20 anesthetized pigs, intracoronary 100 pmol/mL DAG infusion with a constant heart rate and aortic blood pressure, increased coronary blood flow and NO release, whereas reducing coronary vascular resistances (P < .05). Dose responses to DAG were evaluated in five pigs. No effects on cardiac contractility/relaxation or myocardial oxygen consumption were observed. Moreover, whereas the blockade of muscarinic cholinoceptors (n = 5) or α- and ß-adrenoceptors (n = 5 each) did not abolish the observed responses, NO synthase inhibition (n = 5) prevented the effects of DAG on coronary blood flow and NO release. In coronary artery endothelial cells, DAG dose dependently increased NO release through cAMP signaling and ERK1/2, Akt, and p38 MAPK involvement as well as the phosphorylation of endothelial NO synthase. In conclusion, in anesthetized pigs, DAG primarily increased cardiac perfusion through the involvement of NO release. Moreover, the phosphorylation of ERK1/2 and Akt appears to play roles in eliciting the observed NO production in coronary artery endothelial cells.

Influence of Ultraviolet Radiation on the Association between 25-Hydroxy Vitamin D Levels and Cardiovascular Risk Factors in Obesity.

OBJECTIVE: To establish if the correction with estimates of ultraviolet (UV) exposure influences the association between 25-OH-vitamin D (25OHD) levels and metabolic variables. STUDY DESIGN: A cross-sectional study was performed in 575 obese children and adolescents (>6 years of age) in a tertiary referral center. Cardiovascular risk factors were measured. The estimate of UV exposure was evaluated by 3 methods: (1) season; (2) mean of UV radiation (UVR); and (3) mean of UV index (UVI). UVR and UVI were considered at 1 (UVR 1 month prior to testing [UVR1], UVI 1 month prior to testing [UVI1]) or 3 (UVR 3 months prior to testing [UVR3], UVI 3 months prior to testing [UVI3]) months prior to testing. All analyses were corrected for confounders (sex, age, puberty, body mass index, waist circumference, the inclusion and exclusion of estimates of UV exposure). RESULTS: The 25OHD levels were associated with seasons, UVR1, UVR3, UVI1, and UVI3, and best associations with UVR3 and UVI3. In all models, total cholesterol, low-density lipoprotein cholesterol and triglycerides were negatively associated with 25OHD levels. The strength of the association increased with no correction, correction for seasons, UVR, and UVI. UVR3 and UVI3 performed better than UVR1 and UVI3. CONCLUSIONS: Higher lipid concentrations were associated with low 25OHD levels in obese children and adolescents with the power of the association dependent on the estimates of UVR. As the mean values 3 months prior to testing for both UVR and UVI determined the best associations, the interval of the steady state time of 25OHD levels could be preferentially used in the metabolic studies. Controlling for an estimate of UVR is important to decrease the heterogeneity of studies.

Effect of monomeric adiponectin on cardiac function and perfusion in anesthetized pig.

Adiponectin, the most abundant adipokine released by adipose tissue, appears to play an important role in the regulation of vascular endothelial and cardiac function. To date, however, the physiological effects of human monomeric adiponectin on the coronary vasculature and myocardial systo-diastolic function, as well as on parasympathetic/sympathetic involvement and nitric oxide (NO) release, have not yet been investigated. Thus, we planned to determine the primary in vivo effects of human monomeric adiponectin on coronary blood flow and cardiac contractility/relaxation and the related role of autonomic nervous system, adiponectin receptors, and NO. In 30 anesthetized pigs, human monomeric adiponectin was infused into the left anterior descending coronary artery at constant heart rate and arterial blood pressure, and the effects on coronary blood flow, left ventricular systo-diastolic function, myocardial oxygen metabolism, and NO release were examined. The mechanisms of the observed hemodynamic responses were also analyzed by repeating the highest dose of human monomeric adiponectin infusion after autonomic nervous system and NO blockade, and after specific adiponectin 1 receptor antagonist administration. Intracoronary human monomeric adiponectin caused dose-related increases of coronary blood flow and cardiac function. Those effects were accompanied by increased coronary NO release and coronary adiponectin levels. Moreover, the vascular effects of the peptide were prevented by blockade of ß2-adrenoceptors and NO synthase, whereas all effects of human monomeric adiponectin were prevented by adiponectin 1 receptor inhibitor. In conclusion, human monomeric adiponectin primarily increased coronary blood flow and cardiac systo-diastolic function through the involvement of specific receptors, ß2-adrenoceptors, and NO release.

High-end normal adrenocorticotropic hormone and cortisol levels are associated with specific cardiovascular risk factors in pediatric obesity: a cross-sectional study.

BACKGROUND: The hypothalamic-pituitary-adrenal (HPA) axis, and in particular cortisol, has been reported to be involved in obesity-associated metabolic disturbances in adults and in selected populations of adolescents. The aim of this study was to investigate the association between morning adrenocorticotropic hormone (ACTH) and cortisol levels and cardiovascular risk factors in overweight or obese Caucasian children and adolescents. METHODS: This cross-sectional study of 450 obese children and adolescents (aged 4 to 18 years) was performed in a tertiary referral center. ACTH, cortisol, cardiovascular risk factors (fasting and post-challenge glucose, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, and hypertension) and insulin resistance were evaluated. All analyses were corrected for confounding factors (sex, age, puberty, body mass index), and odds ratios were determined. RESULTS: ACTH and cortisol levels were positively associated with systolic and diastolic blood pressure, triglycerides, fasting glucose and insulin resistance. Cortisol, but not ACTH, was also positively associated with LDL-cholesterol. When adjusted for confounding factors, an association between ACTH and 2 h post-oral glucose tolerance test glucose was revealed. After stratification according to cardiovascular risk factors and adjustment for possible confounding factors, ACTH levels were significantly higher in subjects with triglycerides ≥90th percentile (P <0.02) and impaired fasting glucose or glucose tolerance (P <0.001). Higher cortisol levels were found in subjects with blood pressure ≥95th percentile and LDL-cholesterol ≥90th percentile. Overall, the highest tertiles of ACTH (>5.92 pmol/l) and cortisol (>383.5 nmol/l) although within the normal range were associated with increases in cardiovascular risk factors in this population. CONCLUSIONS: In obese children and adolescents, high morning ACTH and cortisol levels are associated with cardiovascular risk factors. High ACTH levels are associated with high triglyceride levels and hyperglycemia, while high cortisol is associated with hypertension and high LDL-cholesterol. These specific relationships suggest complex mechanisms through which the HPA axis may contribute to metabolic impairments in obesity, and merit further investigations.