Increases in insulin sensitivity among obese youth are associated with gene expression changes in whole blood

Identification of Key LncRNAs and Pathways in Prediabetes and Type 2 Diabetes Mellitus for Hypertriglyceridemia Patients Based on Weighted Gene Co-Expression Network Analysis

Aims

Prevalence of prediabetes and type 2 diabetes mellitus(T2DM) are increasing worldwide. Key lncRNAs were detected to provide a reference for searching potential biomarkers of prediabetes and T2DM in hypertriglyceridemia patients.

Methods

The study included 18 hypertriglyceridemia patients: 6 newly diagnosed type 2 diabetes patients, 6 samples with prediabetes and 6 samples with normal blood glucose. Weighted gene co-expression network analysis (WGCNA) was conducted to construct co-expression network and obtain modules related to blood glucose, thus detecting key lncRNAs.

Results

The green, yellow and yellow module was significantly related to blood glucose in T2DM versus normal controls, T2DM versus prediabetes, prediabetes versus normal controls, respectively. ENST00000503273, ENST00000462720, ENST00000480633 and ENST00000485392 were detected as key lncRNAs for the above three groups, respectively.

Conclusions

For hypertriglyceridemia patients with different blood glucose levels, ENST00000503273, ENST00000462720 and ENST00000480633 could be potential biomarkers of T2DM.

Response heterogeneity to lifestyle intervention among Latino adolescents

OBJECTIVE

To characterize the heterogeneity in response to lifestyle intervention among Latino adolescents with obesity.

METHODS

We conducted secondary data analysis of 90 Latino adolescents (age 15.4 ± 0.9 y, female 56.7%) with obesity (BMI% 98.1 ± 1.5%) that were enrolled in a 3 month lifestyle intervention and were followed for a year. Covariance pattern mixture models identified response phenotypes defined by changes in insulin sensitivity as measured using a 2 hour oral glucose tolerance test. Baseline characteristics were compared across response phenotypes using one-way ANOVA and chi-square test.

RESULTS

Three distinct response phenotypes (PH1, PH2, PH3) were identified. PH1 exhibited the most robust response defined by the greatest increase in insulin sensitivity over time (β ± SE, linear 0.52 ± 0.17, P < .001; quadratic -0.03 ± 0.01, P = .001). PH2 showed non-significant changes, while PH3 demonstrated modest short-term increases in insulin sensitivity which were not sustained over time (linear 0.08 ± 0.03, P = .002; quadratic -0.01 ± 0.002, P = .003). At baseline, PH3 (1.1 ± 0.4) was the most insulin resistant phenotype and exhibited the highest BMI% (98.5 ± 1.1%), 2 hours glucose concentrations (144.0 ± 27.5 mg/dL), and lowest beta-cell function as estimated by the oral disposition index (4.5 ± 2.8).

CONCLUSION

Response to lifestyle intervention varies among Latino youth with obesity and suggests that precision approaches are warranted to meet the prevention needs of high risk youth.

Mechanisms of obesity-induced metabolic and vascular dysfunctions

Obesity has reached epidemic proportions and its prevalence is climbing. Obesity is characterized by hypertrophied adipocytes with a dysregulated adipokine secretion profile, increased recruitment of inflammatory cells, and impaired metabolic homeostasis that eventually results in the development of systemic insulin resistance, a phenotype of type 2 diabetes. Nitric oxide synthase (NOS) is an enzyme that converts L-arginine to nitric oxide (NO), which functions to maintain vascular and adipocyte homeostasis. Arginase is a ureohydrolase enzyme that competes with NOS for L-arginine. Arginase activity/expression is upregulated in obesity, which results in diminished bioavailability of NO, impairing both adipocyte and vascular endothelial cell function. Given the emerging role of NO in the regulation of adipocyte physiology and metabolic capacity, this review explores the interplay between arginase and NO, and their effect on the development of metabolic disorders, cardiovascular diseases, and mitochondrial dysfunction in obesity. A comprehensive understanding of the mechanisms involved in the development of obesity-induced metabolic and vascular dysfunction is necessary for the identification of more effective and tailored therapeutic avenues for their prevention and treatment.

Serum and gene expression levels of CT-1, IL-6, and TNF-α after a lifestyle intervention in obese children

BACKGROUND

Inflammation related molecules such as tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and cardiotrophin-1 (CT-1) are highly expressed in obese individuals and could partly explain some comorbidities associated to obesity. In obese children, lifestyle interventions are able to lower inflammation and reduce cardiovascular risk factors associated with obesity. The aim of the present work was to study changes in inflammation-related molecules serum and peripheral blood mononuclear cells (PBMC) transcript levels after a 10-week lifestyle intervention in obese children and asses their potential association with glucose metabolism.

METHODS

Twenty-three obese children (mean age 11.5 years; 48% males) underwent a 10-week lifestyle not controlled intervention trial. Anthropometric and biochemical measurements were analyzed. Transcript analysis for CT-1, IL-6, and TNF-α in PBMC were performed by RT-PCR. Serum cytokine levels were also measured at baseline and after 10-weeks.

RESULTS

Participants achieved a significant reduction in body adiposity (0.34 decrease in body mass index-standard deviation), total cholesterol, and glucose levels after 10-weeks. A Significant decrease in serum TNF-α and C reactive protein (CRP) were observed. CT-1 transcript levels were significantly reduced (P = .005) after lifestyle intervention, and these changes were significantly correlated with changes in serum CT-1 levels (r = 0.451; P = .031). In multiple regression analysis baseline CT-1 transcript levels were positively associated with final insulin (R² = 0.506; P = .035) and HOMA-IR values (R² = 0.473; P = .034).

CONCLUSIONS

We reported that serum CRP, TNF-α, as well as PBMC CT-1 transcript levels were reduced after lifestyle intervention in obese children. More studies are needed to clarify the role of inflammation-related molecules in glucose metabolism.

Expression Profile of Genes Potentially Associated with Adequate Glycemic Control in Patients with Type 2 Diabetes Mellitus

Despite increasing research in type 2 diabetes mellitus (T2D), there are few studies showing the impact of the poor glycemic control on biological processes occurring in T2D. In order to identify potential genes related to poorly/well-controlled patients with T2D, our strategy of investigation included a primary screen by microarray (Human Genome U133) in a small group of individuals followed by an independent validation in a greater group using RT-qPCR. Ninety patients were divided as follows: poorly controlled T2D (G1), well-controlled T2D (G2), and normoglycemic individuals (G3). After using affy package in R, differentially expressed genes (DEGs) were prospected as candidate genes potentially relevant for the glycemic control in T2D patients. After validation by RT-qPCR, the obtained DEGs were as follows-G1 + G2 versus G3: HLA-DQA1, SOS1, and BRCA2; G2 versus G1: ENO2, VAMP2, CCND3, CEBPD, LGALS12, AGBL5, MAP2K5, and PPAP2B; G2 versus G3: HLA-DQB1, MCM4, and SEC13; and G1 versus G3: PPIC. This demonstrated a systemic exacerbation of the gene expression related to immune response in T2D patients. Moreover, genes related to lipid metabolisms and DNA replication/repair were influenced by the glycemic control. In conclusion, this study pointed out candidate genes potentially associated with adequate glycemic control in T2D patients, contributing to the knowledge of how the glycemic control could systemically influence gene expression.

Impact of parental weight status on a school-based weight management programme designed for Mexican-American children

BACKGROUND

While overweight and obese children are more likely to have overweight or obese parents, less is known about the effect of parental weight status on children's success in weight management programmes.

OBJECTIVES

This study was a secondary data analysis of a randomized controlled trial and investigated the impact of having zero, one or two obese parents on children's success in a school-based weight management programme.

METHODS

Sixty-one Mexican-American children participated in a 24-week school-based weight management intervention which took place in 2005-2006. Children's heights and weights were measured at baseline, 3, 6 and 12 months. Parental weight status was assessed at baseline. Repeated measures anova and ancova were conducted to compare changes in children's weight within and between groups, respectively.

RESULTS

Within-group comparisons revealed that the intervention led to significant decreases in standardized body mass index (zBMI) for children with zero (F = 23.16, P < .001) or one obese (F = 4.99, P < .05) parent. Between-group comparisons indicated that children with zero and one obese parents demonstrated greater decreases in zBMI compared to children with two obese parents at every time point.

CONCLUSIONS

The school-based weight management programme appears to be most efficacious for children with one or no obese parents compared to children with two obese parents. These results demonstrate the need to consider parental weight status when engaging in childhood weight management efforts.

Exercise and diabetes: relevance and causes for response variability

Exercise as a key prevention strategy for diabetes and obesity is commonly accepted and recommended throughout the world. Unfortunately, not all individuals profit to the same extent, some exhibit exercise resistance. This phenomenon of non-response to exercise is found for several endpoints, including glucose tolerance and insulin sensitivity. Since these non-responders are of notable quantity, there is the need to understand the underlying mechanisms and to identify predictors of response. This displays the basis to develop personalized training intervention regimes. In this review, we summarize the current knowledge on response variability, with focus on human studies and improvement of glucose homeostasis as outcome.

Exercise for obese youth: refocusing attention from weight loss to health gains

Despite evidence to the contrary, exercise interventions for obese youth target weight loss as a means of improving health. Using Exercise is Medicine® as a framework, we present a conceptual model for the beneficial effects of exercise independent of weight loss in obese youth and highlight novel biomarkers of cardiometabolic health that could prove useful as interventional targets for this population.