Polymorphisms −374 T/A and −429 T/C of the Receptor for Advanced Glycation End-Products (RAGE) and Serum Levels of RAGE (sRAGE) Are Not Associated with Metabolic Syndrome

RAGE is a multi-ligand transmembrane glycoprotein that promotes biological signals associated with inflammatory responses and degenerative diseases. sRAGE is a soluble variant, proposed as an inhibitor of RAGE activity. −374 T/A and −429 T/C polymorphisms of the advanced glycation end products receptor AGER gene are associated with the development of some diseases, such as type of cancer, cardiovascular disease, and micro and macrovascular disease in diabetes among others but their role in metabolic syndrome (MS) is still unknown. We studied 80 healthy men without MS, and 80 men with MS according to the harmonized criteria. −374 T/A and −429 T/C polymorphisms were genotyped by RT-PCR, and sRAGE was measured by ELISA. Allelic and genotypic frequencies did not differ between Non-MS and MS groups (−374 T/A p = 0.48, p = 0.57 and −429 T/C p = 0.36, p = 0.59). Significant differences were found in fasting glucose levels and diastolic blood pressure among the genotypes of the −374 T/A polymorphism in the Non-MS group (p < 0.01 and p = 0.008). Glucose levels were different between −429 T/C genotypes in the MS group (p = 0.02). sRAGE levels were similar in both groups, but in the Non-MS group showed a significant difference between individuals with only 1 or 2 components of the metabolic syndrome (p = 0.047). However, no associations of any SNP with MS were found (recessive model p = 0.48, dominant model p = 0.82 for −374 T/A; recessive model p = 0.48, dominant model p = 0.42 for −429 T/C). −374 T/A and −429 T/C polymorphisms are not associated with MS in Mexican population and have no influence on serum sRAGE levels.

Soluble receptor for advanced glycation end products and lipid profile ratio as cardiovascular risk markers in children with obesity

INTRODUCTION

Obesity has been shown to be associated with low levels of soluble receptor for advanced glycation end products (sRAGE).

OBJECTIVE

To evaluate the levels of sRAGE and its association with the lipid index in children with obesity.

METHODS

Cross-sectional study of children with obesity aged between six and 11 years. Anthropometric measurements, glucose, lipid profile, insulin and sRAGE were evaluated; body mass index, total cholesterol/high-density cholesterol (TC/HDL-C), triglycerides/glucose (TG/glucose), and triglycerides/HDL-C (TG-HDL-C) ratios and HOMA-IR were also calculated.

RESULTS

Eighty children were studied, among which 50% were males and 50% females. Females had higher values for waist circumference, HOMA-IR, and TG/HDL-C and TG/glucose ratios. No significant differences were found for sRAGE. When the variables were compared according to TG/HDL-C ratio tertiles, higher TC/HDL, TG/glucose, and sRAGE values were found at upper tertile. A significant correlation was observed between sRAGE and HOMA-IR (p < 0.03) in males, and between sRAGE and TG/HDL-C (p < 0.01) and TG/glucose ratios (p < 0.008) in females.

CONCLUSIONS

The female gender showed more cardiovascular risk factors and higher sRAGE at TG/HDL-C upper tertile. Further studies are required to test the possible predictive effect of higher risk for developing metabolic and cardiovascular complications.

Curcumin prevents proteins expression changes of oxidative phosphorylation, cellular stress response, and lipid metabolism proteins in liver of mice fed a high-fructose diet

Increased fructose consumption has been associated with the development of metabolic diseases due to the modification in protein expression, altering metabolic and signaling pathways. Curcumin is a natural compound with a regulatory effect on genes and metabolic pathways. To identify the fructose-induced protein expression changes and the effect of curcumin on the change of protein expression in the liver of mice fed a standard diet and a high fructose diet, to elucidate the global role of curcumin. Four groups (n = 4/group) of male mice (C57BL6J) of six-weeks-old were formed. One group received a standard diet (C); another received curcumin at 0.75% w/w in the feed (C + C); one more received 30% w/v fructose in drinking water (F); and one group received 30% w/v fructose in drinking water and 0.75% w/w curcumin in food (F + C); for 15 weeks. Proteomic analysis was performed by LC-MS/MS, using the label-free technique with the MaxQuant programs for identification and Perseus for expression change analysis. Differentially expressed proteins (fold change ≥1.5 and p < 0.5) were analyzed by gene ontology and KEGG. A total of 1047 proteins were identified, of which 113 changed their expression in mice fed fructose, compared to the control group, and curcumin modified the expression of 64 proteins in mice fed fructose and curcumin compared to mice that only received fructose. Curcumin prevented the change of expression of 13 proteins involved in oxidative phosphorylation (NDUFB8, NDUFB3, and ATP5L) in the cellular response to stress (PSMA5, HIST1H1D) and lipid metabolism (THRSP, DGAT1, ECI1, and ACOT13). Curcumin in mice fed the standard diet increased the expression of proteins related to oxidative phosphorylation, ribosomes, and PPAR pathways. In addition to fructose, increased expression of proteins involved in oxidative phosphorylation, ribosomes, lipid metabolism, and carbon metabolism. However, curcumin prevented expression change in 13 hepatic proteins of fructose-fed mice involved in oxidative phosphorylation, cellular stress response, and lipid metabolism. SIGNIFICANCE: Curcumin is a natural compound with a regulatory effect on proteins and metabolic pathways. So, curcumin prevents the change of expression in 13 hepatic proteins of fructose-fed mice involved in oxidative phosphorylation, cellular stress response and lipid metabolism, as a supplement with protector activity on fructose-induced toxic effects.

Curcumin Prevents the Glycation of Tricarboxylic Acid Cycle and Cell Respiration Proteins in the Heart of Mice Fed with a High-Fructose Diet

BACKGROUND

A high fructose diet (HFD) induces protein glycation. The latter is related to a higher risk of cardiovascular disease. Curcumin is a natural pleiotropic compound that may possess antiglycant properties.

OBJECTIVE

To analyze the effect of curcumin on the content of glycated proteins in the hearts of 6-week-old mice fed with a HFD for 15 weeks.

METHODS

Mice were allocated in four groups (n = 6/group): a control group that received a standard diet (CT); a group that received 30% w/v fructose in water (F); a group that received 0.75% w/w curcumin supplemented in food (C); a group that received 30% w/v fructose in water and 0.75% w/w curcumin supplemented in food (F+C). The content of glycated proteins in the heart was determined by Western Blot (whereas the spots were detected by 2D-PAGE) using anti-AGE and anti-CML antibodies. A densitometric analysis was performed using the ImageLab software. Glycated proteins were identified by MALDI-TOF-MS, and an ontological analysis was performed in terms of biological processes and molecular function based on the STRING and DAVID databases.

RESULTS

Fourteen glycated protein spots were detected, two of them with anti-AGE and the other 12 with anti-CML. In total, eleven glycated proteins were identified, out of which three had decreased glycation levels due to curcumin exposure. The identified proteins participate in processes such as cellular respiration, oxidative phosphorylation, lipid metabolism, carbohydrate metabolism, the tricarboxylic acid cycle (TAC), and the organization of intermediate filaments.

CONCLUSIONS

Curcumin decreased the fructose-induced glycation level of the ACO2, NDUFS7, and DLAT proteins.

Serum Fatty Acid-Binding Protein 4 Levels in Adolescents: Effect of Insulin Resistance

Background: Fatty acid-binding protein 4 (FABP4) is an adipokine that plays a causative role in obesity and diabetes. In a stratified cross-sectional study with adolescents, we explored whether changes in FABP4 are already present in lean adolescents, provided they display elements of insulin resistance (IR). Methods: Adolescents were divided in four groups according to body mass index and homeostasis model assessment-IR. Results: In metabolically unhealthy lean (MUL) adolescents (MUL, lean with IR), FABP4 was 33% higher than in healthy counterparts (metabolically healthy lean [MHL]). Obese adolescents without IR (metabolically healthy obesity [MHO]) had 50% higher levels of FABP4 than their lean counterparts (MHL), while levels of FABP4 in obese adolescents with IR (metabolically unhealthy obese [MUO]) were 220% higher than those of MUL adolescents. The differences were significant at least with P < 0.005. MUO > MHO > MUL. Our data demonstrate that the known FABP4 defect in adults with obesity also occurs in youth and even in lean adolescents, suggesting an early association between impaired glucose metabolism and FABP4 irrespective of body weight. FABP4 was more sensitive in discerning each of our 4 subgroups than either adiponectin or leptin. Moreover, evidence for a putative early adiponectin resistance in MUL suggests a combined defect in these adolescents that call for early detection and prevention of the metabolic disturbance that should stay away from concentrating only in subjects with obesity. Conclusions: Our data may serve to draw the considerable attention that is currently paid to FABP4 to the adolescent population, irrespective of the presence of obesity. Further studies with larger cohorts and analyses of visceral and liver fat are warranted.

Rare coding variants in 35 genes associate with circulating lipid levels-A multi-ancestry analysis of 170,000 exomes

Large-scale gene sequencing studies for complex traits have the potential to identify causal genes with therapeutic implications. We performed gene-based association testing of blood lipid levels with rare (minor allele frequency < 1%) predicted damaging coding variation by using sequence data from >170,000 individuals from multiple ancestries: 97,493 European, 30,025 South Asian, 16,507 African, 16,440 Hispanic/Latino, 10,420 East Asian, and 1,182 Samoan. We identified 35 genes associated with circulating lipid levels; some of these genes have not been previously associated with lipid levels when using rare coding variation from population-based samples. We prioritize 32 genes in array-based genome-wide association study (GWAS) loci based on aggregations of rare coding variants; three (EVI5, SH2B3, and PLIN1) had no prior association of rare coding variants with lipid levels. Most of our associated genes showed evidence of association among multiple ancestries. Finally, we observed an enrichment of gene-based associations for low-density lipoprotein cholesterol drug target genes and for genes closest to GWAS index single-nucleotide polymorphisms (SNPs). Our results demonstrate that gene-based associations can be beneficial for drug target development and provide evidence that the gene closest to the array-based GWAS index SNP is often the functional gene for blood lipid levels.

Lean adolescents with insulin resistance display higher angiopoietin like protein 3, ApoC-III and chylomicron remnant dyslipidemia

BACKGROUND

Triglyceride-rich lipoproteins (TRL: chylomicrons and VLDL) are a key component of diabetes dyslipoproteinemia and cardiovascular risk. We have shown that it is already prevalent in obese adolescents in association with lipoprotein lipase (LPL) dysregulation. Insulin resistance (IR) suffices to produce TRL dyslipoproteinemia and LPL dysfunction even in the absence of obesity.

METHODS

This cross-sectional study included euglycemic adolescents between 15 and 19 y, classified in 4 groups according to BMI, HOMA-IR and fasting lipid as: metabolically healthy lean (MHL, n = 30), metabolically unhealthy lean (MUL, n = 25), metabolically healthy obese (MHO, = 30), and metabolically unhealthy obese (MUO, n = 42).

RESULTS

As compared to MHL, MUL participants showed 73% higher concentrations of ApoB-48; 84% of ApoC-III; 24% ANGPTL-3; 200% of TG; 218% of VLDL-C and 238% of TG/HDL-C ^c, No changes were found in LPL mass. Interestingly, the differences in these parameters between MUL and MHO were not significant.

CONCLUSION

Euglycemic lean adolescents with IR display TRL dyslipoproteinemia with increased inhibition of LPL as highlighted by higher concentrations of ANGPTL-3, ApoC-III and fasting chylomicron remnants (ApoB-48).

The Relationship Between Psychosocial Factors and Adherence to Treatment in Men, Premenopausal and Menopausal Women with Type 2 Diabetes Mellitus

Introduction

Type 2 Diabetes Mellitus (T2DM) is a chronic disease that begins in adulthood, and is caused by multiple factors. The onset of menopause involves changes that predispose women to the development of T2DM, which can worsen if the adherence to treatment is inadequate due to psychosocial factors or medications. The present study aims to describe the psychosocial factors that may affect adherence to treatment among men and premenopausal and menopausal women with T2DM.

Methods

This was a cross-sectional study of 96 patients with T2DM, who were divided into three groups: 1) men (n=32); 2) premenopausal women (n=32); and 3) menopausal women (n=32). Somatometric and metabolic control data were obtained. Adherence to treatment and psychosocial factors were evaluated: social support, belief in conventional medicine, disease denial, and depressive symptoms.

Results

Adherence to medication had a negative correlation with depressive symptoms in men (p <0.001) and menopausal women (p <0.021). Dietary adherence had a positive correlation with belief in conventional medicine in men (p <0.037) and premenopausal women (p <0.029).

Conclusion

Medication adherence in men and menopausal women was correlated with fewer depressive symptoms. Adherence to diet in men and premenopausal women was correlated with greater belief in conventional medicine. The results show the diversity of psychosocial factors among the groups that must be addressed in order to improve adherence.

Effects of L-Citrulline Supplementation and Aerobic Training on Vascular Function in Individuals with Obesity across the Lifespan

Children with obesity are at higher risk for developing cardiometabolic diseases that once were considered health conditions of adults. Obesity is commonly associated with cardiometabolic risk factors such as dyslipidemia, hyperglycemia, hyperinsulinemia and hypertension that contribute to the development of endothelial dysfunction. Endothelial dysfunction, characterized by reduced nitric oxide (NO) production, precedes vascular abnormalities including atherosclerosis and arterial stiffness. Thus, early detection and treatment of cardiometabolic risk factors are necessary to prevent deleterious vascular consequences of obesity at an early age. Non-pharmacological interventions including L-Citrulline (L-Cit) supplementation and aerobic training stimulate endothelial NO mediated vasodilation, leading to improvements in organ perfusion, blood pressure, arterial stiffness, atherosclerosis and metabolic health (glucose control and lipid profile). Few studies suggest that the combination of L-Cit supplementation and exercise training can be an effective strategy to counteract the adverse effects of obesity on vascular function in older adults. Therefore, this review examined the efficacy of L-Cit supplementation and aerobic training interventions on vascular and metabolic parameters in obese individuals.

Dietary AGEs as Exogenous Boosters of Inflammation

Most chronic modern non-transmissible diseases seem to begin as the result of low-grade inflammation extending over prolonged periods of time. The importance of diet as a source of many pro-inflammatory compounds that could create and sustain such a low-grade inflammatory state cannot be ignored, particularly since we are constantly exposed to them during the day. The focus of this review is on specific components of the diet associated with inflammation, specifically advanced glycation end products (AGEs) that form during thermal processing of food. AGEs are also generated in the body in normal physiology and are widely recognized as increased in diabetes, but many people are unaware of the potential importance of exogenous AGEs ingested in food. We review experimental models, epidemiologic data, and small clinical trials that suggest an important association between dietary intake of these compounds and development of an inflammatory and pro-oxidative state that is conducive to chronic diseases. We compare dietary intake of AGEs with other widely known dietary patterns, such as the Mediterranean and the Dietary Approaches to Stop Hypertension (DASH) diets, as well as the Dietary Inflammation Index (DII). Finally, we delineate in detail the pathophysiological mechanisms induced by dietary AGEs, both direct (i.e., non-receptor-mediated) and indirect (receptor-mediated).

Determinants of penetrance and variable expressivity in monogenic metabolic conditions across 77,184 exomes

Hundreds of thousands of genetic variants have been reported to cause severe monogenic diseases, but the probability that a variant carrier develops the disease (termed penetrance) is unknown for virtually all of them. Additionally, the clinical utility of common polygenetic variation remains uncertain. Using exome sequencing from 77,184 adult individuals (38,618 multi-ancestral individuals from a type 2 diabetes case-control study and 38,566 participants from the UK Biobank, for whom genotype array data were also available), we apply clinical standard-of-care gene variant curation for eight monogenic metabolic conditions. Rare variants causing monogenic diabetes and dyslipidemias display effect sizes significantly larger than the top 1% of the corresponding polygenic scores. Nevertheless, penetrance estimates for monogenic variant carriers average 60% or lower for most conditions. We assess epidemiologic and genetic factors contributing to risk prediction in monogenic variant carriers, demonstrating that inclusion of polygenic variation significantly improves biomarker estimation for two monogenic dyslipidemias.

Contribution of RAGE axis activation to the association between metabolic syndrome and cancer

Far beyond the compelling proofs supporting that the metabolic syndrome represents a risk factor for diabetes and cardiovascular diseases, a growing body of evidence suggests that it is also a risk factor for different types of cancer. However, the involved molecular mechanisms underlying this association are not fully understood, and they have been mainly focused on the individual contributions of each component of the metabolic syndrome such as obesity, hyperglycemia, and high blood pressure to the development of cancer. The Receptor for Advanced Glycation End-products (RAGE) axis activation has emerged as an important contributor to the pathophysiology of many clinical entities, by fueling a chronic inflammatory milieu, and thus supporting an optimal microenvironment to promote tumor growth and progression. In the present review, we intend to highlight that RAGE axis activation is a crosswise element on the potential mechanistic contributions of some relevant components of metabolic syndrome into the association with cancer.

Liquid chromatography-mass spectrometry untargeted metabolomics reveals increased levels of tryptophan indole metabolites in urine of metabolic syndrome patients

Metabolic syndrome (MetS) is a multifactor condition predisposing for diabetes, cardiovascular diseases and other degenerative disorders. Although several diagnostic criteria have been established, none of them is specific and there is a call for better pathophysiological explanation of MetS and for the discovery of molecular biomarkers. Phenotype characterization at metabolome level might be useful for both purposes. To this end, our aim was to perform comparative untargeted metabolomics of urines from MetS patients and from the control group. The study participants included 52 diagnosticated and 50 healthy individuals from Leon city in central Mexico; 23 anthropometric and clinical parameters were measured and submitted to Principal Component Analysis (PCA). The obtained PCA model allowed us for selection of 11 MetS patients and 13 control subjects, correspondingly representative for each of the two groups (clearly separated in PCA). The first morning urines from these subjects were ambulatory collected and, after methanol extraction and acidification, were submitted to capillary liquid chromatography-high resolution mass spectrometry (LC-HRMS). The obtained data were analyzed on MetaboScape® platform (Bruker Daltonics). Specifically, t-test applied to LC-HRMS data revealed several ions presenting at least 3-fold higher intensities in MetS with respect to the control samples (p < 0.05). Data analysis and complementary experiments yielded the identification of the following metabolites: indole-3-acetic acid, indole-3-acetic acid-O-glucuronide, N-(indol-3-ylacetyl) glutamine, indole-3-carbaldehyde and hydroxyhexanoycarnitine. Additionally, indole-3-carboxylic acid was annotated with 2.13-fold higher abundance in MetS patients. To assess the contribution of individual metabolites in the difference between two groups of subjects, partial least square discriminant analysis was performed for LC-HRMS data and the obtained values of variable importance in projection (VIP), confirmed the association of six above mentioned compounds with MetS. Overall, this study provides direct evidence on the disturbed catabolism of tryptophan in metabolic syndrome.

The potential role of dietary advanced glycation endproducts in the development of chronic non-infectious diseases: a narrative review

Increasing clinical and experimental evidence accumulated during the past few decades supports an important role for dietary advanced glycation endproducts (AGE) in the pathogenesis of many chronic non-infectious diseases, such as type 2 diabetes, CVD and others, that are reaching epidemic proportions in the Western world. Although AGE are compounds widely recognised as generated in excess in the body in diabetic patients, the potential importance of exogenous AGE, mostly of dietary origin, has been largely ignored in the general nutrition audience. In the present review we aim to describe dietary AGE, their mechanisms of formation and absorption into the body as well as their main mechanisms of action. We will present in detail current evidence of their potential role in the development of several chronic non-infectious clinical conditions, some general suggestions on how to restrict them in the diet and evidence regarding the potential benefits of lowering their consumption.

Free Fructose Intake Decreases Soluble RAGE Receptor (sRAGE) and Glyoxal and Methylglyoxal Urinary Excretion on Healthy Volunteers

Objectives

Free fructose but not total fructose intake could contribute to the formation of advanced glycation end products (AGEs) and Maillard reaction products in the intestinal lumen. Therefore, the aim of this study was to compare serum levels of fructosamine, soluble receptor for AGEs (sRAGE), and urinary levels of glyoxal and methylglyoxal after free fructose and total fructose intake.

Methods

This is a randomized crossover study, approved by the Institutional Committee of Bioethics in Research of the University of Guanajuato (CIBIUG). Twelve clinically healthy subjects, 20–30 years old, were recruited. During the first visit, participants were randomly assigned to one of two treatments, an oral load of fructose (40 g) or total fructose (40 g fructose and 40 g glucose), in addition to their assigned treatment subjects received 25 g of hydrolyzed protein (Nature Best Isopure®) After a washing period (one week), participants were crossed over to receive the other treatment. Blood and urine samples were collected at baseline and after three hours of the oral load of each treatment. Glucose, creatinine, and lipids serum levels were measured with commercial kits. Insulin, fructosamine, and sRAGE serum levels were determined with ELISA commercial kits. Glyoxal and methylglyoxal urine levels were quantified by HPLC. Data analysis was completed using STATISTICA 10 and IBM SPSS Statistics 24.0 software. The results were considered significant with a value of P &lt; 0.05.

Results

After free Fructose intake, participants had a significant decrease in sRAGE (1327 pg/L vs 1282 pg/L, P = 0.028), and in urine levels of glyoxal (0.63 ng/mg vs 0.24 ng/mg P = 0.028) and methylglyoxal (0.42 ng/mg vs 0.13 ng/mg P = 0.002). After Fructose and glucose intake, participants only had a significant decreased in serum sRAGE (1256 pg/L vs 1199 pg/L, P = 0.015). Fructosamine did not showed a difference after either intervention.

Conclusions

The consumption of free fructose decreased serum sRAGE levels, as well as urinary excretion of glyoxal and methylglyoxal. These results may suggest a possible in vivo formation of AGEs by consuming free fructose. Nevertheless, more studies are necessary to assess the formation of methylglyoxal derived AGEs.

Funding Sources

This project was supported by the University of Guanajuato through the Research and Postgraduate Support Department (DAIP).

SUN-LB131 Association of Receptor for Advanced Glycation End Product (RAGE) Gene Polymorphisms & Serum Levels of Soluble RAGE (sRAGE) With Metabolic Syndrome (MS) in Mexican Population

Background. RAGE, a multi-ligand type 1 transmembrane glycoprotein belonging to the immunoglobulin superfamily, transduces biological signals associated with chronic cellular stress related with inflammatory responses, tissue damage, chronic and degenerative diseases (1). sRAGE is a variant of RAGE derived from cell surface cleavage mechanisms that could potentially act as endogenous inhibitors of RAGE activity (2). RAGE gene is highly polymorphic, with polymorphisms that could be responsible for disease development, like -374T/A (rs1800624) and -429T/C (rs1800625) polymorphisms. These are located in the promoter region and have marked effect on transcriptional activity. However, there have been conflicting findings between the potential association of RAGE polymorphisms and the development of diseases. In this work, we evaluated -374T/A (rs1800624) and -429T/C (rs1800625) polymorphisms and measured serum sRAGE levels in Mexican population with MS.

Methods. A group of healthy men without any component of the MS (n=80), and a group of men with the MS (n=80) according to the harmonized criteria for the MS were included in this study. Blood genomic DNA was isolated and genotyped by RT-PCR for the -374T/A and -429T/C polymorphisms of RAGE gene. sRAGE in serum was measured with an ELISA kit. Results. The studied population complied with the Hardy-Weinberg equilibrium (p=0.58 for -374T/A, and p=0.79 for -429T/C). Differences were observed in all the components of the MS between the two groups (MS vs. healthy subjects, p<0.000). However, there were no differences in the population according to their genotype for the -374T/A (p=0.57) and -429T/C (p=0.59) polymorphisms. There was no difference in glucose (p=0.22), triglycerides (p=0.99), and cHDL (p=0.88) levels, or waist circumference (p=0.84) according to the genotype for the -374T/A polymorphism. The same was observed for the -429T/C polymorphism (glucose p=0.57, triglycerides p=0.69, cHDL p=0.77, waist circumference p=0.99). No association of MS with the -374T/A nor 429T/C polymorphism was found. There were no differences between groups in circulating sRAGE levels (p=0.132). Conclusion. According to our results, the -374T/A and -429T/C polymorphisms of RAGE gene are not associated with the MS in Mexican population, and have no influence on serum sRAGE levels. Some other factors could be playing a role for the high prevalence of the MS, such as eating habits. Gender should be taken into consideration, for our study was performed in men exclusively. References. (1) Serveaux-Dancer M et al., Dis Markers. 2019 Feb 4;2019:2067353. (2) Schmidt AM. Vascul Pharmacol. 2015 Sep;72:1-8.

SUN-575 Levels of Nesfatin-1 in Adolescents, and Its Association with Body Mass Index and Risk of Cardiovascular Disease

Nesfastin-1 is a recently discovered anorexigenic neuropeptide, which seems to follow the signaling pathway of melanocortin, and is involved in cardiovascular regulation (1). It is expressed in several tissues, including pancreatic islet cells, the central nervous system, In subcutaneous and visceral fat tissue, among others (2). There are few and controversial data that assess the levels of nesfatin-1 and its relationship with the cardiovascular disease. The aim of this study was to evaluate the serum levels of nesfatin-1 in adolescents with different metabolic status and BMI and its association with cardiovascular risk factors (glucose, lipid profile).

Material and methods: This cross-sectional study included adolescents between 15 and 19 years old, classified in 3 groups according to BMI and HOMA-IR: adolescents with normal weight without metabolic alterations (n ​​= 30), metabolically healthy obese (MHO) n = 30 and metabolically unhealthy obese adolescents (MUO) n = 42. Anthropometric measurements were performed, a fasting blood sample was taken to quantify glucose, lipid profile and creatinine. Insulin and nesfatin-1 concentrations were measured by ELISA. Statistical tests employed were Kruskal Wallis, Spearman correlation.

Results: the group of adolescents MUO had higher levels of total-C (p&lt;0.0002); triglycerides (p&lt;0.00001) compared to the control and MHO; higher levels of nesfatin-1 (p=0.0002) and lower levels of HDL-C (p&lt;0.002) compared to the control group. A positive correlation was between nesfatin-1 and BMI (p&lt;0.001), triglycerides (p&lt;0.027), and HOMA-IR (p&lt;0.025) and negative correlation with HDL-C (p&lt;0.026)

Conclusion: Our results show that metabolically unhealthy obese adolescents have higher concentrations of nesfatin-1, showing an association with traditional cardiovascular risk factors, which could lead to the development of cardiovascular disease.

Nothing to disclose GK, KC, GOA, LCC, FMM, GA, GSME

Sources of research support: Grant University of Guanajuato (DAIP 302/2018)

References: (1) Oh-I et al., Nature. 2006; 443:709–712. (2) Stengel A et al., Regulatory Peptides. 2010; 163:18–23

Soluble Receptor for Advanced Glycation End Products and Its Correlation with Vascular Damage in Adolescents with Obesity

OBJECTIVE

The aim of this study was to evaluate soluble receptor for advanced glycation end products (sRAGE) and advanced glycation end products (AGEs) in adolescents with and without obesity (OB) and their correlation with vascular damage.

METHODS

This is a cross-sectional study with 15-19 years old adolescents: 33 with OB and 33 with normal weight (NW), each group included 17 male and 16 female. Lipid profile, insulin, carboxymethylysine (CML), sRAGE, total AGEs, and dietary AGEs intake (dAGEs) were evaluated. Vascular damage was measured by flow-mediated vasodilation (FMD) and arterial stiffness index (Iβ). Homeostatic model assessment-insulin (HOMA-IR) and atherogenic index (AI) were calculated.

RESULTS

The group with OB had higher triglycerides (TG; p < 0.0001), AI (p < 0.001), HOMA-IR (p < 0.0001), dAGEs intake (p < 0.0001), lower CML (p = 0.05), total AGEs (p < 0.01), sRAGE (p < 0.001), and FMD (p < 0.002). In the total group, sRAGE correlated with AI (r = -0.26 p = 0.037); in the NW group, CML correlated with Iβ (r = -0.36; p = 0.037); and in the group of adolescents with OB, sRAGE correlated with FMD (r = -0.37; p = 0.037) and Iβ (r = 0.47; p = 0.006), while CML and total AGEs correlated with AI, p = 0.007 and p < 0.01, respectively).

CONCLUSIONS

The group of adolescents with OB showed higher cardiometabolic risk as shown by higher TG, AI, HOMA-IR, and lower sRAGE and FMD. sRAGE correlated negatively with FMD and positively with Iβ, so it could be suggested as a biochemical marker of impaired endothelial function.

INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-1, NON-ALCOHOLIC FATTY LIVER DISEASE, AND ITS RELATIONSHIP WITH FRUCTOSE CONSUMPTION IN CHILDREN WITH OBESITY

Background

Over consumption of added sugar is associated with obesity, non-alcoholic fatty liver disease (NAFLD), and insulin resistance (IR).

Objective

The objective of the study was to study the insulin-like growth factor binding protein-1 (IGFBP-1) and NAFLD and their relationship with fructose consumption in children with obesity.

Methods

A cross-sectional study was carried out in children 6-11 years old with obesity. Anthropometric measurements, fructose consumption, glucose, lipid profile, insulin, and IGFBP-1 levels were evaluated; the homeostatic model assessment of IR (HOMA-IR) was used. NAFLD was evaluated by ultrasound.

Results

We studied 83 children with a mean age of 9.2 ± 1.3 years. About 93% of the girls presented IR and lower levels of IGFBP-1 (p = 0.0001). The group with the lower levels of IGFBP-1 had higher HOMA-IR (p = 0.000002); IGFBP-1 was associated with fructose consumption (r = -0.25; p = 0.03), body mass index (BMI) (r=-0.42; p = 0.02), and HOMA-IR (r=-0.61; p = 0.002). About 81% of the children were classified as having mild or moderate/severe NAFLD, and these groups had higher HOMA-IR (p = 0.036) and fructose consumption (p = 0.0014).

Conclusions

The girls had more metabolic alterations. The group with lower levels of IGFBP-1 (hepatic IR) was associated with higher BMI, HOMA-IR, and fructose consumption; the group with higher severity of NAFLD showed higher HOMA-IR and fructose consumption.

A Short-term Diet High in Carboxymethyl-lysine (CML) Increases Urinary Excretion but Not Serum CML Levels (P12-012-19)

Objectives

Dietary advanced glycation end products (AGEs) are a group of compounds formed by the Maillard reaction. Carboxymethyl-lysine (CML), a marker of AGEs in foods, may contribute to cardiometabolic diseases. However, CML health effects and its absorption and excretion in healthy individuals remained controversial. For this reason, the aim of this study was to evaluate serum and urinary excretion CML levels in healthy adults after a short-term diet high in CML.

Methods

A randomized clinical trial was conducted in 30 healthy adults (18–35 years old). After signing the informed consent, subjects were randomly assigned to a low or a high CML diet. All participant followed a diet with low CML content for seven days (washing period) before the 5-days intervention. During the 5 days participants received all the foods according to their group. Blood and 24-hour urine samples were collected before and after the intervention to evaluate serum and urinary CML levels. CML measurement in foods, serum, and urine was carried out by HPLC-ESI-ITMS/MS. Comparison between groups was carried out by a t-test. The research was approved by the Institutional Review Board and the clinical trial registration number NCT03208946.

Results

Biochemical and anthropometric variables were similar between groups (P > 0.05). The average consumption of CML was 1.93 ± 1.47 mg/day for the low CML diet and 5.03 ± 2.22 mg/day for the high CML diet, whereas caloric, protein and fat intake were similar. Serum levels decreased significantly in both groups (low diet: basal 488.1 ± 135.4 μg/L, final 383.2 ± 78.6 μg/L (P = 0.007)) (high diet: basal 463.5 ± 90.3 μg/L, final 390.3 ± 99.1 μg/L (P = 0.02)). No significant difference was found when comparing the final CML levels between groups (P = 0.47). The excretion of CML in urine was adjusted by creatinine (mg) and the high CML group had a greater excretion (4.5 ± 8.0 ug CML/mg) when compared to the low CML group (−1.5 ± 7.2 ug CML/mg) (P = 0.04).

Conclusions

A high CML diet increases urinary CML excretion levels in healthy adults when compared to a low CML diet. There were no significant differences in serum CML levels between both groups. However, a greater decrease was observed in the subjects who followed a diet with a low content of AGEs.

Funding Sources

University of Guanajuato. CONACYT.

Higher D-lactate levels are associated with higher prevalence of small dense low-density lipoprotein in obese adolescents

BACKGROUND

Childhood obesity is associated with insulin resistance (IR), increased levels of small dense low-density lipoprotein (sd-LDL) as well as with augmented hepatic de novo lipogenesis, which implies increased triose phosphate fluxes that may lead to increased methylglyoxal (MG) and its catabolic end product D-lactate. We hypothesized that obese adolescents have increased D-lactate serum levels associated with high incidence of sd-LDL.

METHODS

This is a cross-sectional study where the anthropometric characteristics, atherogenic dyslipidemia complex, sd-LDL (Lipoprint, Quantimetrix) and D-lactate (kinetic enzymatic analysis) were explored in 30 lean vs. 30 obese adolescents (16 females and 14 males per group) without metabolic syndrome (MetS). Endothelial function by flow-mediated dilation (FMD, by ultrasound) and arterial lesion by carotid intima media thickness (CIMT, by ultrasound) were also measured.

RESULTS

The mean age of participants was 16.8 ± 1.4 years. Obese adolescents had a body mass index of 32.7 ± 3.8 vs. 21.8 ± 2.1 in lean participants. The obesity group showed higher D-lactate levels: 6.2 ± 3.0 vs. 4.5 ± 2.5 μmol/L, higher levels of insulin: 15 (9.6-23.5) vs. 7.9 (6.5-10.5) μIU/mL; triglyceride (TG): 1.46 (1.1-1.8) vs. 0.84 (0.6-1.2) mmol/L; non-high-density lipoprotein-cholesterol (NON-HDL-C): 2.8 ± 0.9 vs. 2.3 ± 0.7 mmol/L; total cholesterol (TC)/HDL-C) index: 2.9 ± 0.7 vs. 2.4 ± 0.5; TG/HDL-C index: 2.2 (1.5-2.8) vs. 1.1 (0.8-1.8); %LDL-3: 4.2 ± 4.07 vs. 1.9 ± 2.7; smaller LDL size: 270.6 ± 3 vs. 272.2 ± 1.1 Å. D-lactate correlated positively with LDL-2: r = 0.44 and LDL-3 (sd-LDL): r = 0.49 and negatively with large LDL-1: r = -0.48 and LDL size: r = -0.46; (p<0.05, p<0.01, p<0.001 and p<0.0001, respectively). Obese adolescents showed higher CIMT: 0.51 ± 0.08 vs. 0.46 ± 0.08 mm and lower FMD: 20.3% ± 6.7% vs. 26.0% ± 9.3%.

CONCLUSIONS

Obese adolescents display subclinical signs of IR and endothelial dysfunction. Higher serum sd-LDL levels correlated positively with D-lactate levels. These findings suggest an association between atherogenic dyslipoproteinemia and whole body MG fluxes already detectable in apparently healthy obese adolescents.

Advanced glycation end products and their receptors did not show any association with body mass parameters in metabolically healthy adolescents

AIM

We determined the relationship between circulating advanced glycation end products (AGEs), AGE receptors and homeostatic model assessment for insulin resistance (HOMA-IR) in metabolically healthy obese and normal weight adolescents.

METHODS

In 2015, we recruited 80 normal weight adolescents and 80 with obesity from schools Leon city, Mexico, and put them into metabolically healthy (HOMA-IR <3.0) and unhealthy (HOMA-IR >3.0) groups. We measured their body mass index (BMI) and carried out detailed blood analyses.

RESULTS

We found a higher triglycerides, triglycerides/high-density lipoproteins cholesterol (TG/HDL-C) index, HOMA-IR, tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in the metabolically healthy group and found correlations between HOMA-IR with BMI, the TG/HDL-C index and IL-6 and the TG/HDL-C index and BMI and (TNF-α). There was no correlation between markers of obesity and circulating N-carboxymethyl-lysine (CML) or soluble receptor for advanced glycation end products (sRAGE). Some unhealthy adolescents had higher CML (15.5 ± 2.7 U/mL, p < 0.028) and sRAGE (3123 ± 1364 pg/mL, p < 0.001) than the healthy group.

CONCLUSION

HOMA-IR and the TG/HDL-C index were associated with BMI and inflammation markers. CML and sRAGE were not associated with obesity or inflammation. These parameters were higher in unhealthy obese adolescents.

Changes in circulating levels of carboxymethyllysine, soluble receptor for advanced glycation end products (sRAGE), and inflammation markers in women during normal pregnancy

Objective: To determine the circulating levels of insulin, Nε-carboxymethyllysine (CML), soluble receptor for advanced glycation end products (sRAGE), and markers of inflammation and oxidative stress (OS) in maternal and umbilical cord blood in a cohort of healthy women with normal pregnancy.Methods: We conducted an observational longitudinal study in a group of women (n = 31; age range 18-39 years) with healthy pregnancy starting at 30 weeks of gestation and finishing at the time of delivery. We collected weight and height in the participants and their neonates and calculated body mass index (BMI). Blood from each patient was collected at 30th week of pregnancy and at delivery when a sample of cord blood was also obtained. Glucose, lipid profile, CML, sRAGE, malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), highly sensitivity C-reactive protein (hsPCR), and insulin were determined. The study was approved by the University of Guanajuato Institutional Ethics Committee.Results: All pregnancies reached term (mean gestational time 38.9 ± 0.83 weeks) and there were no maternal complications. Mean age was 27.6 years. Lipid profile values were higher in the group compared with our values in nonpregnant women. During pregnancy, levels of insulin increased (p < .0006), CML (p < .0001) and sRAGE (p < .01) decreased, levels of MDA did not change, while those of TNF-α and hsPCR tended to increase. In the neonates, we found lower levels of CML (p < .003), hsPCR (p < .004), and insulin (p < .004) and higher levels of sRAGE (p < .013) and TNF-α (p < .022) compared to their mothers at delivery. In the total group, we found association of CML of the mother at baseline with the CML (p < .0006) and MDA (p < .002) in neonates, while maternal sRAGE at the end of pregnancy was associated with CML (p < .004) of their neonates.Conclusions: Our study confirms that normal pregnancy is accompanied by insulin resistance (IR) and significant increase in lipid profile, and demonstrates that circulating levels of CML and sRAGE decreased significantly at the end of pregnancy. The lack of association between the course of insulin levels and those of CML probably results from the predominant role of placental factors in the pathogenesis of IR in pregnancy. sRAGE levels in the neonates are markedly increased compared to their mothers suggesting a placental origin of this compound which may have a protective effect on the fetus since sRAGE restricts Advanced glycation end product (AGE) effects and may exert anti-inflammatory effects.

Comparative evaluation of three different ELISA assays and HPLC-ESI-ITMS/MS for the analysis of Nε-carboxymethyl lysine in food samples

N^ε-carboxymethyl-lysine (CML) is measured in food, but there is a controversy concerning the most convenient yet reliable method(s) for this task. This work compares three different ELISA assays and HPLC-ESI-ITMS/MS for the analysis of CML in several food items. The four methods showed the same decreasing order of CML concentration: beef, bacon>chicken > fish>dairy products>grain products>fruits/vegetables. HPLC-ESI-ITMS/MS results highly correlated with those obtained by ELISA performed with monoclonal CML-antibody (β=0.98, p<0.0001) whereas My Bio Source® kit results were not correlated with those provided by Lamider®. Small differences of CML concentrations in food items prepared by different culinary treatment were clearly distinguished by HPLC-ESI-ITMS/MS, but could not always be detected by ELISA. This work demonstrates a reasonable relationship between CM determined by ELISA and HPLC-ESI-ITMS/MS and therefore supports the implementation of ELISA in food CML/AGEs screening.

Dietary Advanced Glycation End Products and Cardiometabolic Risk

PURPOSE OF REVIEW

This report analyzes emerging evidence about the role of dietary advanced glycation end products (AGEs) as a cardiometabolic risk factor. Two important aspects are discussed: First, the modulation of AGE load by dietary AGEs; second, if the evidence of clinical and observational studies is enough to make dietary recommendations towards lowering AGE intake.

RECENT FINDINGS

Clinical studies in subjects with diabetes mellitus have shown that high intake of dietary AGEs increases inflammation markers, oxidative stress, and could impair endothelial function. In subjects at risk for cardiometabolic diseases (with overweight, obesity, or prediabetes), dietary AGE restriction decreases some inflammatory molecules and improves insulin sensitivity. However, studies in healthy subjects are limited, and not all of the studies have shown a decrease in circulating AGEs. Therefore, it is still unclear if dietary AGEs represent a health concern for people potentially at risk for cardiometabolic diseases. The evidence shows that dietary AGEs are bioavailable and absorbed, and the rate of excretion depends on dietary intake. The metabolic fate of most dietary AGEs remains unknown. Regardless, most studies have shown that by diminishing AGE intake, circulating levels will also decrease. Thus, dietary AGEs can modulate the AGE load at least in patients with DM, overweight, or obesity. Studies with specific clinical outcomes and large-scale observational studies are needed for a better risk assessment of dietary AGEs and to establish dietary recommendations accordingly.

Effect of Restriction of Foods with High Fructose Corn Syrup Content on Metabolic Indices and Fatty Liver in Obese Children

OBJECTIVE

We examined the effect of restriction of foods with high fructose content in obese school children.

METHODS

In a clinical study, we selected 54 obese children 6 to 11 years old with high fructose consumption (>70 g/day) in order indicate dietary fructose restriction (<20 g/day) for 6 weeks. Anthropometry, liver ultrasound as well as glucose, insulin, lipids, leptin, IGFBP1, and RBP4 serum levels were collected.

RESULTS

The group of children had 80% adherence and reported decreased fructose consumption (110 ± 38.6 to 11.4 ± 12.0 g/day) and also a significant decrease in caloric (2,384 ± 568 to 1,757 ± 387 kcal/day) and carbohydrate consumption (302 ± 80.4 to 203 ± 56.0 g/day). The severity of steatosis improved significantly after fructose restriction (p < 0.000001). However, no changes in BMI, systolic blood pressure, or diastolic blood pressure were found. Only triglyceride levels decreased (1.44 ± 0.43 to 1.31 ± 0.38 mmol/l), High-densitiy lipoprotein cholesterol showed a marginal increase (1.45 ± 0.19 to 1.56 ± 0.44 mmol/l). Insulin resistance and RBP4 did not change.

CONCLUSIONS

In school children, the restriction of high fructose foods with a decrease of caloric and carbohydrate intake at 6 weeks did not induce weight loss; however, triglyceride levels and hepatic steatosis decreased. Differences with other studies in regard to weight loss may be explained by adaptive changes on metabolic expenditure.

The AGE-RAGE Axis and Its Relationship to Markers of Cardiovascular Disease in Newly Diagnosed Diabetic Patients

AIM

The purpose of the study was the simultaneous measurement of all the different components of the AGE-RAGE axis as well as several non-invasive markers of cardiovascular disease (CVD) in a cohort of newly diagnosed diabetic patients.

MATERIALS AND METHODS

In 80 newly diagnosed diabetic patients we measured serum carboxymethyllysine (CML), soluble RAGE (sRAGE) and peripheral mononuclear (PMNC) RAGE and AGER1 mRNA together with ICAM-1, VCAM-1, and malondialdehyde (MDA). We also assessed cardiovascular function by measurement of flow-mediated vasodilation (FMD), intima-media thickness (IMT) and arterial stiffness. Univariant correlation analysis was used to determine correlation between the variables in the study and multiple regression analysis was used to examine the association between the AGE-RAGE axis components and FMD, IMT and arterial stiffness.

RESULTS

Serum CML correlated positively with sRAGE, PMNC RAGE, HOMA-IR, ICAM-1, VCAM-1 and MDA, but inversely with PMNC AGER1. sRAGE and RAGE was positively correlated with AGER; IMT was positively correlated with HOMA-IR, ICAM-1, VCAM-1, MDA, and sRAGE and arterial stiffness had correlation with HOMA-IR, ICAM-1, VCAM-1, MDA, CML, sRAGE, AGER1 and RAGE. In multivariate analysis we found a significant relationship between CML with PMNC RAGE, HOMA-IR; sRAGE with VCAM-1 and MDA; PMNC RAGE with PMNC AGER1and CML; PMNC AGER1 with PMNC RAGE; FMD with sRAGE, CML and HbA1c; IMT with sRAGE, and arterial stiffness with sRAGE, sCML and AGER1.

CONCLUSIONS

We found significant and strong associations between the different components of the AGE-RAGE axis and also found significant association between AGE-RAGE axis markers, especially sRAGE with several noninvasive markers of cardiovascular disease risk. sRAGE, an easily measured parameter in blood, may potentially be used as a surrogate marker of AGEs-RAGE in patients with diabetes.

Dietary restriction in obese children and its relation with eating behavior, fibroblast growth factor 21 and leptin: a prospective clinical intervention study

BACKGROUND

Obesity is significant problem involving eating behavior and peripheral metabolic conditions. The effect of carbohydrate and fat restriction on appetite regulation, fibroblast growth factor 21 (FGF21) and leptin in children has not been defined. Our objective was to compare the effect of both diets.

METHODS

One hundred and twenty children with body mass index (BMI) higher than the equivalent of 30 kg/m(2) for an adult, as corrected for gender and age were randomly assigned to (n = 60) a low-carbohydrate (L-CHO) diet or (n = 60) a low-fat (L-F) diet for 2 months. Fifty-three (88.3 %) subjects on the low-carbohydrate-diet and 45 (75 %) on the low-fat diet completed the study. Anthropometric measures, leptin and FGF21 levels were measured before and after the intervention. Comparison of the data for both of the diet groups was carried out using the t-test for independent variables. Intragroup comparisons before and after of each of the dietary treatments were performed using ANOVA for repeated measures. Factors associated with FGF21, leptin levels and satiety, were analyzed by multiple regression.

RESULTS

After both of the diets, weight, leptin, food responsiveness, and enjoyment of food significantly decreased and high density lipoprotein cholesterol (HDL) increased, but FGF21 decreased. Before and after both of the interventions FGF21 was associated with triglycerides. Before the diet, satiety was associated with lower screen time (p < 0.04) and insulin levels (p < 0.05).

CONCLUSIONS

Both dietary restrictions improved the metabolic and hormonal parameters of obese children. FGF21 is an indicator of a beneficial metabolic response in younger children. After 2 months an adaptation of the eating behavior to food restriction was observed.

Dietary advanced glycation end products and their role in health and disease

Over the past 2 decades there has been increasing evidence supporting an important contribution from food-derived advanced glycation end products (AGEs) to the body pool of AGEs and therefore increased oxidative stress and inflammation, processes that play a major role in the causation of chronic diseases. A 3-d symposium (1st Latin American Symposium of AGEs) to discuss this subject took place in Guanajuato, Mexico, on 1-3 October 2014 with the participation of researchers from several countries. This review is a summary of the different presentations and subjects discussed, and it is divided into 4 sections. The first section deals with current general knowledge about AGEs. The second section dwells on mechanisms of action of AGEs, with special emphasis on the receptor for advanced glycation end products and the potential role of AGEs in neurodegenerative diseases. The third section discusses different approaches to decrease the AGE burden. The last section discusses current methodologic problems with measurement of AGEs in different samples. The subject under discussion is complex and extensive and cannot be completely covered in a short review. Therefore, some areas of interest have been left out because of space. However, we hope this review illustrates currently known facts about dietary AGEs as well as pointing out areas that require further research.

Molybdenum and copper in four varieties of common bean (Phaseolus vulgaris): new data of potential utility in designing healthy diet for diabetic patients

Experimental evidence indicates that diabetic patients and individuals with impaired copper homeostasis could be at risk of molybdenum toxicity. A self-administered food frequency questionnaire revealed that in central Mexico, diabetic patients with severe complications tend to consume beans more often than individuals with less advanced disease. Four varieties of Phaseolus vulgaris were comparatively evaluated as the dietary sources of two elements; the results showed molybdenum concentration decreasing in the order peruvian > pinto > mayflower > black, whereas for copper, the order was peruvian > pinto ∼ black > mayflower. The two elements were determined in pre-soaking water, cooked legumes, and broth obtained in cooking procedure; an in vitro gut model was also applied to assess potentially bioavailable fraction of both elements in cooked beans. The results indicated that the black variety would be the healthiest bean choice for diabetic patients and individuals susceptible to Mo toxicity. Relatively low total molybdenum was found in this variety (2.9 ± 1.4 versus 4.3-10.9 μg g(-1) in other types), element availability was also low (15 % in supernatant from enzymolysis, 24.9 % in combined broth + supernatant fractions), and the molar ratio of Cu/Mo was the highest among four types (41, versus Cu/Mo <10 in peruvian, pinto, or mayflower). Considering peruvian and pinto beans, broth elimination would help to lower molybdenum intake with marginal effect on Cu/Mo molar ratio. This recommendation would be especially important for peruvian variety, which provided 1090, 803, and 197 μg day(-1) of molybdenum in raw grains, broth + supernatant, and supernatant, respectively (based on 100-g portion), exceeding the recommended daily allowance of 45 μg day(-1).

Whole-body and hepatic insulin resistance in obese children

Background

Insulin resistance may be assessed as whole body or hepatic.

Objective

To study factors associated with both types of insulin resistance.

Methods

Cross-sectional study of 182 obese children. Somatometric measurements were registered, and the following three adiposity indexes were compared: BMI, waist-to-height ratio and visceral adiposity. Whole-body insulin resistance was evaluated using HOMA-IR, with 2.5 as the cut-off point. Hepatic insulin resistance was considered for IGFBP-1 level quartiles 1 to 3 (<6.67 ng/ml). We determined metabolite and hormone levels and performed a liver ultrasound.

Results

The majority, 73.1%, of obese children had whole-body insulin resistance and hepatic insulin resistance, while 7% did not have either type. HOMA-IR was negatively associated with IGFBP-1 and positively associated with BMI, triglycerides, leptin and mother's BMI. Girls had increased HOMA-IR. IGFBP-1 was negatively associated with waist-to-height ratio, age, leptin, HOMA-IR and IGF-I. We did not find HOMA-IR or IGFBP-1 associated with fatty liver.

Conclusion

In school-aged children, BMI is the best metric to predict whole-body insulin resistance, and waist-to-height ratio is the best predictor of hepatic insulin resistance, indicating that central obesity is important for hepatic insulin resistance. The reciprocal negative association of IGFBP-1 and HOMA-IR may represent a strong interaction of the physiological processes of both whole-body and hepatic insulin resistance.

Markers of the progression of complications in patients with type 2 diabetes: a one-year longitudinal study

Hyperglycemia induces tissue damage and complications by mechanisms that produce advanced glycation end-products (AGEs) and inflammation.To investigate the factors associated with the progression of complications in Type 2 diabetes patients.We recruited 157 patients (110 women and 47 men) with diabetes for more than 5 years who were non-smokers and did not have current infections or chronic diseases. Patients were grouped according to neuropathy, nephropathy, and retinopathy status: without (I), slight or moderate (II), and severe complications (III). We measured glucose, lipids and HbA1c, low molecular weight AGEs (LMW AGEs), high sensitivity C-reactive protein (CRP), TNF-α, IL-6, and malondialdehyde (MDA). Patients were re-evaluated 1 year later.Patients were 52.2±6.8 years old with 11.0±4.9 years since diagnosis. After 1 year, circulating AGEs increased (p<0.0001) and eGFR decreased (p<0.0007) in groups II and III. IL-6 and MDA decreased in groups I and II. CRP (p<0.029) and AGEs (p<0.0001) increased in group II. At baseline in group I, TNF-α levels were higher (p<0.002) in patients who later developed complications. In group II, TNF-α levels (p<0.015) and microalbuminuria (p<0.00004) were higher in patients whose complications progressed. Logistic regression analysis showed that complication progress was significantly associated with log(albuminuria) (p<0.004) and log(TNF-α) (p<0.008). In the total group, AGEs were associated with age (p<0.024) and HbA1c (p<0.026).Our results suggest that baseline TNF-α is an important predictor of complication progression in Type 2 diabetes patients. AGEs also increased during the deterioration of renal function after 1 year of follow-up observation.

High-performance liquid chromatography determination of glyoxal, methylglyoxal, and diacetyl in urine using 4-methoxy-o-phenylenediamine as derivatizing reagent

Bioanalytical relevance of glyoxal (Go) and methylglyoxal (MGo) arises from their role as biomarkers of glycation processes and oxidative stress. The third compound of interest in this work is diacetyl (DMGo), a component of different food products and alcoholic beverages and one of the small α-ketoaldehydes previously reported in urine. The original idea for the determination of the above compounds by reversed phase high-performance liquid chromatography (HPLC) with fluorimetric detection was to use 4-methoxy-o-phenylenediamine (4MPD) as a derivatizing reagent and diethylglyoxal (DEGo) as internal standard. Acetonitrile was added to urine for matrix precipitation, and derivatization reaction was carried out in the diluted supernatant at neutral pH (40 °C, 4 h); after acidification, salt-induced phase separation enabled recovery of the obtained quinoxalines in the acetonitrile layer. The separation was achieved within 12 min using a C18 Kinetex column and gradient elution. The calibration detection limits for Go, MGo, and DMGo were 0.46, 0.39, and 0.28 μg/L, respectively. Within-day precision for real-world samples did not exceed 6%. Several urine samples from healthy volunteers, diabetic subjects, and juvenile swimmers were analyzed. The sensitivity of the procedure proposed here enabled detection of differences between analyte concentrations in urine from patients at different clinical or exposure-related conditions.

Dietary advanced glycation end products restriction diminishes inflammation markers and oxidative stress in patients with type 2 diabetes mellitus

The augmented consumption of dietary advanced glycation end products (dAGEs) has been associated with increased oxidative stress and inflammation, however, there is insufficient information over the effect on insulin resistance. The objective of the present study is to investigate the effect of dAGEs restriction on tumor necrosis factor-α (TNF-α), malondialdehyde, C-reactive protein (CRP), and insulin resistance in DM2 patients. We carried out a randomized 6 weeks prospective study in two groups of patients: subjects with a standard diet (n = 13), vs low dAGEs (n = 13). At the beginning and the end of study, we collected anthropometric measurements, and values of circulating glucose, HbA1c, lipids, insulin, serum AGEs, CRP, TNF-α and malondialdehyde. Anthropometric measurements, glucose, and lipids were similar in both groups at base line and at the end of the study. Estimation of basal dAGEs was similar in both groups; after 6 weeks it was unchanged in the standard group but in the low dAGEs group decreased by 44% (p<0.0002). Changes in TNF-α levels were different under standard diet (12.5 ± 14.7) as compared with low dAGEs (−18.36 ± 17.1, p<0.00001); changes in malondialdehyde were different in the respective groups (2.0 ± 2.61 and −0.83 ± 2.0, p<0.005) no changes were found for insulin levels or HOMA-IR. In conclusion, The dAGEs restriction decreased significantly TNF-α and malondialdehyde levels.

Role of Dietary Advanced Glycation End Products in Diabetes Mellitus

Dietary advanced glycation end products (AGEs) can be formed via the Maillard reaction and several alternative pathways. AGEs exert their deleterious effects by damaging protein structure and function, as well as through activation of cellular mechanisms. At the cellular level, the damaging effects of AGEs have been attributed to several AGE-binding proteins. Increased levels of AGEs have been implicated in several chronic diseases, including diabetes-related complications such as renal diseases, retinopathy, neuropathy, and cardiovascular diseases, as well as delayed wound healing. To investigate the role of AGEs thoroughly, a reliable assessment of dietary AGEs is needed. Varying methodology, diverse food preparation, and quantification of a variety of dietary AGEs makes this a complex goal. In addition, some antiglycation food products may balance or offset the negative impact of dietary AGEs.

Telomere length and type 2 diabetes in males, a premature aging syndrome

BACKGROUND

Increased telomere shortening has been demonstrated in several diseases including type 2 diabetes. However, it is not known whether telomere length changes during the course of type 2 diabetes.

OBJECTIVE

To determine telomere length at different stages of type 2 diabetes, including early and late stages.

METHODS

A total of 93 males with type 2 diabetes and 10 years or more since original diagnosis; 96 males with less than one year of diagnosis; 98 age matched healthy males. Telomere length was estimated by means of real-time polymerase chain reaction. Fasting venous blood samples were obtained for measurement of lipid peroxidation and inflammation markers.

RESULTS

We found a greater telomere shortening in group (A) with type 2 diabetes of 10 years or more since original diagnosis, compared with the control group (C) of healthy males (5.4 vs 9.6 Kb) (p = 0.04) and with group B (5.4 vs 8.7 kb) (p = 0.05). With regard to inflammatory markers TNF-α, malondialdehyde peroxidation and adiponectin we found significant differences.

CONCLUSION

Telomere shortening increases with the duration of diabetes. The time of exhibition suggests in parallel that the progressive increase of inflammation and/or oxidative stress plays a direct role in telomere shortening.

Association of the TNF-α -308G/A polymorphism with family history of type 2 diabetes mellitus in a Mexican population

AIMS

We examined the possible association of the -308G/A polymorphism of the TNF-α promoter gene in type 2 diabetes mellitus (DM2) patients and in non-diabetic subjects with and without family history of DM2.

METHODS

We studied 87 non-diabetic subjects without DM2 family history in at least one of two generations, 48 non-diabetic subjects with DM2 family history and 95 DM2 patients. Genotyping was carried out by PCR-RFLP.

RESULTS

The frequency of TNF-α -308G/A genotype was significantly lower in non-diabetic subjects without DM2 relatives (6%) as compared to DM2 patients (24%) (odds ratio (OR)=5.24; 95% confidence interval (CI)=1.9-15.8, p<0.0005), but similar to non-diabetic subjects with DM2 relatives (29%) (OR=0.77; CI=0.3-1.7, p=0.4). Logistic regression analysis showed the association of TNF-α -308G/A polymorphism with DM2 family history (OR=5.80; CI=1.77-18.98, p<0.0003).

CONCLUSIONS

Our results suggest that TNF-α -308G/A polymorphism is associated with DM2 family history and is a risk factor for DM2.

Coping strategies and adherence to treatment in patients with type 2 diabetes mellitus

INTRODUCTION

Diverse psychosocial and cultural factors are related to adherence to treatment of type 2 Diabetes mellitus (DM2) such as social support, coping styles and the cost of medical attention.

OBJECTIVE

To study the influence of diverse psychosocial factors on adherence to treatment in patients with DM2.

MATERIAL AND METHODS

In a cross sectional design we studied adherence to diet and medication, and its relationship with CS for diabetes, belief in conventional medicine, social support, and the perception of the burden of treatment cost on family finances.

RESULTS

We included 210 patients a mean age of 56.3 years, 9.4 years since diagnosis. Male DM patients had better adherence to medication (p<0.016) and social support (p<0.004), and higher rates for supportant CS (31.8 vs. 29.0; p<0.009). Adherence to diet was associated with belief in conventional medicine (p<0.035) and marginally related to fatalistic CS (p<0.05). After testing social security coverage as dummy variable, a marginal association was found (p<0.15). Adherence to medication was associated with supportant CS (p<0.02) and marginally with avoidant CS (p<0.05).

CONCLUSIONS

Supportant CS was more frequent in men. Belief in conventional medicine, and supportant CS were associated with adherence to treatment. These factors should be considered for a more rational approach for the management of disease.

Prediabetes in rural and urban children in 3 states in Mexico

The authors studied the frequency, distribution, and factors associated with prediabetes (fasting glucose, 100-125 mg/dL) in rural and urban children from San Luis Potosí, León, and Querétaro in central Mexico. Family history, somatometry, and levels of fasting insulin, glucose, and lipids were collected in 1238 children 6 to 13 years of age. The authors found no cases of type 2 diabetes and a 5.7% frequency of prediabetes. The group with prediabetes had higher homeostasis model assessment of insulin resistance scores and total cholesterol and high-density lipoprotein cholesterol levels. Prediabetes was more frequent in León, with similar distribution in rural and urban children. The frequency of insulin resistance was 24.1%, with higher figures in urban groups and in San Luis Potosí. In multivariate analysis, prediabetes was associated with insulin resistance and residence in León. The authors concluded that in central Mexico the frequency of prediabetes is significant, and it is associated with insulin resistance and a geographic location, but not with obesity or urban vs rural dwelling.

Advanced glycosylation end products in skin, serum, saliva and urine and its association with complications of patients with type 2 diabetes mellitus

BACKGROUND

The accumulation of advanced glycation end products (AGEs) has a key role in the pathophysiology of diabetes complications. Comparison of AGEs measurement in serum, skin, saliva and urine has not been reported.

AIMS

To compare AGEs in serum, skin, saliva and urine in patients with Type 2 diabetes mellitus, with complications at different stages.

MATERIALS AND METHODS

We examined 50 patients with Type 2 diabetes mellitus (40 women and 10 men) grouped according to the progression of neuropathy, nephropathy and retinopathy. The AGEs content in serum, skin, saliva and urine was measured by spectrofluorometry HPLC.

RESULTS

The patients had a mean age of 56.5 +/- 7.7 yr and 12.8 +/- 6.7 yr since diagnosis. AGEs in skin correlated with years since diagnosis (p = 0.0005). AGEs in serum, skin and saliva increased with the progression of complications, nevertheless, in urine a trend to diminution was found. In the group with end-stage renal disease (ESRD), AGEs in serum increased in greater proportion. In order to account for the decreased AGEs clearance, we corrected the values for creatinine levels, and AGEs in skin gave a better association with complications.

CONCLUSIONS

The AGEs measurement in skin, serum and saliva are useful to evaluate diabetes complications. AGEs in skin are associated with years since diagnosis of diabetes. Correction for renal function might discriminate AGEs in situ formation from accumulation.

Clinical and radiological improvement of periodontal disease in patients with type 2 diabetes mellitus treated with alendronate: a randomized, placebo-controlled trial

BACKGROUND

Alendronate (ALN) is an aminobisphosphonate commonly used for osteoporosis in postmenopausal women. We studied the effect of ALN on bone loss prevention in type 2 diabetes mellitus patients with periodontal disease.

METHODS

In a controlled double-blind, randomized study we evaluated prospectively diabetic patients paired by gender and years since diagnosis for 6 months. The study included 40 patients (20 men and 20 women), 50 to 60 years old, with more than 5 years since diagnosis of diabetes and established periodontitis. They were randomly allocated to alendronate (10 mg/daily) or placebo treatment for 6 months. The endpoints of treatment were: the distance between the alveolar bone border and the cemento-enamel-junction (CEJ) evaluated by means of digital radiographic imaging, a biochemical marker of bone resorption (urine N-telopeptide) (Ntx), and periodontal parameters. Metabolic control was assessed at baseline and after 6 months.

RESULTS

Baseline and 6-month glycated hemoglobin levels were similar in both groups. Alendronate induced a significant decrease in NTx at 6 months (P = 0.006). Periodontal parameters improved in both groups. However, they were significantly better for the ALN treated group. Alveolar bone border-CEJ distance increased in the placebo, but decreased in the ALN group (P = 0.0003).

CONCLUSIONS

In type-2 diabetic patients, alendronate induced more improvement in alveolar bone crest height than control therapy. No differences in urinary N-telopeptide or glycated hemoglobin were observed in this short-term randomized controlled pilot trial.

Perceived psychological stress in diabetes mellitus type 2

We studied the factors associated with perceived psychosocial stress in patients with diabetes mellitus type 2. A cross-sectional study was carried out in 105 patients (27 men and 78 women) with a mean age of 51.6 (50.2-52.5, 95% CI) years and 8.6 (7.3-9.8, 95% CI) years since diagnosis. The patients were overweight with body mass index (BMI) of 27.6, and most of them had deficient metabolic control (mean glucose of 10.6 nmol/L and HbA1c of 9.2%). Glycated hemoglobin was associated with BMI (negatively, p = 0.002), with adherence to diet (negatively, p = 0.027) and with years since diagnosis (p = 0.031). The association with BMI was found only in women. It was explained by the fact that obese women had fewer years since diagnosis, and recently diagnosed patients have a better metabolic control. A stepwise multiple regression analysis showed perceived stress associated with percent body fat and blood glucose in the total group, with years since diagnosis in women (p = 0.02), and with BMI in men (p = 0.03). No association was found between perceived stress and adherence to treatment. We concluded that in our group, perceived stress was associated with obesity and metabolic control.

Plasma epinephrine and norepinephrine response to stimuli in autonomic neuropathy of type 2 diabetes mellitus

The objective of this study was to examine epinephrine and norepinephrine plasma levels in patients with clinical type 2 diabetes mellitus, at different stages of autonomic neuropathy. Eighteen patients were classified in groups without (n = 6) and with early (n = 6), definite (n = 3) and severe (n = 3) neuropathy. Blood catecholamine levels were measured after the Valsalva maneuver, cold exposure and orthostatic tests. The norepinephrine basal levels were lower in patients with severe neuropathy (0.4 +/- 0.2 nmol/l), compared with the group with no neuropathy (1.3 +/- 0.5 nm/l, p = 0.034), or with early neuropathy (1.3 +/- 0.7 nm/l, p = 0.035). After the Valsalva maneuver, no increase was found in the group with severe alteration. In patients without neuropathy, cold exposure induced a peak of norepinephrine at 5 min (delta = 1.9 +/- 1.6 nmol/l). The increase was lower in groups with definite and severe damage. In patients with definite or moderate neuropathy, the orthostatic test induced minimal or no response. The epinephrine response to the maneuvers was not significant, and no differences were found among the groups. Norepinephrine basal levels and cold responses are diminished in patients with definite and severe autonomic neuropathy. This provides further evidence on their impaired response to stress. The comparable epinephrine levels in patients with or without autonomic neuropathy indicates that adrenal medullar function is not significantly altered.

Denial of disease in Type 2 diabetes mellitus: its influence on metabolic control and associated factors

AIMS

We have investigated denial of disease in patients with Type 2 diabetes mellitus (DM) and its possible association with metabolic control, and with psychosocial variables: satisfaction with medical care, perceived stress, social support, knowledge of diabetes and belief in conventional medicine.

METHODS

We studied 160 patients in a cross-sectional design, in two groups: with (70) and without social security coverage (90). The mean age for the total group was 53.6 years, with a known diabetes duration of 8.1 years.

RESULTS

Denial of disease was similar in those with < or = 5 years since diagnosis (73 patients) and with > 5 years (87). The group without social security had higher scores of perceived stress, and lower scores of social support, knowledge about diabetes and belief in conventional medicine; denial, however, was similar in the two groups with or without social security. Multiple regression analysis showed that denial of disease was positively associated with HbA1c in the total group (P < 0.001), in the groups with < or = 5 and > 5 years since diagnosis, as well as in the groups with or without social security. Denial was also associated with years since diagnosis (P = 0.009) for the group with < or = 5 years since diagnosis.

CONCLUSIONS

We concluded that, in patients with Type 2DM denial of disease increases with time during the first 5 years of evolution of diabetes; is associated with poor metabolic control; but is not associated with knowledge of diabetes, belief in conventional medicine, social support or perceived stress.