Soluble receptor for advanced glycation end-products (sRAGE) in childhood obesity: association with gene expression of RAGE and cardiometabolic markers

Introduction

Introduction: advanced glycation end-products (AGEs) interact with the receptor for AGEs (RAGE). Full-length RAGE is associated with intracellular signal transduction, and soluble-RAGE (sRAGE) lacks the transmembrane and cytoplasmic domains, acting as a competitive inhibitor of AGEs-RAGE binding. sRAGE levels in healthy children are associated with cell surface expression of RAGE. However, the expression of RAGE has not been explored in childhood obesity. Objective: the study aim was to evaluate the sRAGE levels and the gene expression of RAGE in children and its association with cardiometabolic markers. Methods: this is a cross-sectional study with 6-11-year children, 20 with overweight and 20 with obesity. Anthropometric measurements included waist circumference (cm) (WC), neck circumference (NC), weight (kg), fat mass (%), trunk fat (kg), muscular mass (kg), height (cm), and body mass index (BMI) (kg/m2). Blood samples following an overnight fast were collected to measure glucose (mg/dl) and lipid profile with colorimetric methods. sRAGE was determined in serum using the enzyme-linked immunosorbent assay (ELISA). Quantitative reverse transcription (RT-qPCR) was performed to analyze RAGE transcripts in peripheral blood mononuclear cells isolated by Ficoll®-Hypaque. Results: we found higher RAGE (p = 0.0315) and lower sRAGE (p = 0.0305) levels in the obesity group. sRAGE level showed a negative correlation with RAGE (r = -0.35) and BMI (r = -0.24), and positive with HDL-cholesterol (r = 0.29). Regression analysis suggests that HDL-C and RAGE levels are predictors of sRAGE levels. Conclusions: expression of RAGE is associated with lower sRAGE levels in childhood obesity. Moreover, obese children show higher cardiometabolic risk markers, and a positively associated with sRAGE.

Feasibility of Raman spectroscopy as a potential in vivo tool to screen for pre-diabetes and diabetes

In this article, we investigated the feasibility of using Raman spectroscopy and multivariate analysis method to noninvasively screen for prediabetes and diabetes in vivo. Raman measurements were performed on the skin from 56 patients with diabetes, 19 prediabetic patients and 32 healthy volunteers. These spectra were collected along with reference values provided by the standard glycated hemoglobin (HbA1c) assay. A multiclass principal component analysis and support vector machine (PCA-SVM) model was created from the labeled Raman spectra and was validated through a two-layer cross-validation scheme. Classification accuracy of the model was 94.3% with an area under the receiver operating characteristic curve AUC of 0.76 (0.65-0.84) for the prediabetic group, 0.86 (0.71-0.93) for the diabetic group and 0.97(0.93-0.99) for the control group. Our results suggest the feasibility of using Raman spectroscopy for the classification of prediabetes and diabetes in vivo.

Novel Adiposity and Biochemical-Anthropometric Indices to Identify Cardiometabolic Risk and Metabolic Syndrome in Mexican Adults

Although several indices used in clinical practice identify cardiometabolic risk (CR) and metabolic syndrome (MetS), it is imperative to develop indices for specific populations. Therefore, we proposed and validated sex-specific indices to identify CR associated with visceral adipose tissue (VAT) accumulation or MetS in Mexican adults. Additionally, a cut-off value for the visceral fat area (VFA) to identify CR was proposed. Clinical, anthropometric, biochemical, and body composition variables were evaluated in 904 subjects (25-45 years old) (84.4% men). Multiple and logistic regressions were used to model the indices and ROC curve analysis to determine predictive performance. An additional cohort (n = 186) was used for indices validation, and Cohen's kappa coefficient was employed for agreement analysis. The proposed sex-specific indices, called Mexican adiposity indices (MAIs) and biochemical-anthropometric indices (BAIs), were good predictors for CR and MetS. The kappa coefficients showed a moderate agreement level. The VFA cut-off value chosen to identify CR was 100.3 cm2 because it had the best combination of sensitivity (66.8%) and specificity (64.4%). MAIs and BAIs could be clinical tools to identify either CR associated to VAT accumulation or MetS, respectively. A VFA cut-off value of 100.3 cm2 could identify CR in Mexican men.

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 < 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).

miRNAs as Biomarkers of Metabolic Disorders Associated with Visceral Adiposity, a Study Protocol

Objectives

The expression of some micro RNAs is associated independently with visceral fat and metabolic disorders. However, the mechanisms of regulation by which these miRNAs could increase visceral fat and its possible association with metabolic disorders have not been fully elucidated. Therefore, the objective was to evaluate and compare the expression levels of miR-146b, miR-130, miR-181a5p, and miR-33a in subjects according to their visceral fat area and their metabolic state.

Methods

Men 25–45 years old (n = 118) with normal weight, overweight or obese (18.5–34.9 Kg/m2) were recruited for a cross-sectional study. After consent, anthropometric measures and body composition were evaluated by bioelectrical impedance analysis (Inbody S10). A blood sample was taken for analysis of glucose and lipid profile. Subjects were classified into six groups according to their body mass index (BMI), VAT area and metabolic alterations, (1: normal weight, <100 cm2 and no metabolic alterations, 2: overweight, <100 cm2 and no metabolic alterations, 3: overweight, ≥100 cm2 and no metabolic alterations, 4: overweight, <100 cm2 and metabolic alterations, 5: overweight, ≥100 cm2 and metabolic alterations, 6: obese, ≥140 cm2 and metabolic alterations). The expression levels of miR-33a, miR-155 y miR-181a-5p, were quantified by RT digital PCR technique, using serum samples. Reverse transcription was used to obtain complementary DNA (cDNA) (TaqMan® Reverse Transcription Kit) from RNA samples. Then cDNA was mixed with the specific miRNA primers and a fluorescent probe for DNA, and then the sample was transferred to a droplet generator (QX200 Droplet Generator, Bio-Rad). The generated droplets were amplified by conventional PCR. Finally, the PCR products will be collocated in the droplet lector QX200, and to analyze the number of droplets, the software QuantaSoft will be used. Differences between groups were tested with ANOVA and Tukey posthoc.

Results

A total of 300 subjects were evaluated, and 118 meet the inclusion criteria. According to their BMI, VAT area, clinical, and metabolic variables (blood pressure, glucose, and lipid profile), subjects were assigned to one of the six groups.

Conclusions

At the end of the study, we will have found if the proposed miRNAs could be used as biomarkers of metabolic disorders associated with visceral adiposity.

Funding Sources

DAIP 2019.

Acute Effect of Black Bean (Phaseolus vulgaris L.) Hydrolyzed Protein on Glucose Levels in Adults with Prediabetes and Normal Glucose Tolerance

Objectives

In silico, biochemical, in vitro, and in vivo assays have shown that black bean hydrolyzed protein (HPF) could decrease glucose absorption by inhibiting digestive enzymes and blocking gastrointestinal transporters. Therefore, the objective was to evaluate the acute effect of different doses of HPF on glucose levels in adults with normal glucose tolerance (NGT) and with prediabetes.

Methods

A double-blind, placebo-controlled, randomized clinical trial was conducted on 31 adults with NGT and 24 adults with prediabetes. Participants were 25–50-year-old and with a body mass index (BMI) between 25–34.9 kg/m2. After consent, participants were randomized into four groups, placebo or the corresponding HPF (powder) treatment (D1:2.5 g, D2:3.7 g, D3:5 g). Subjects received the placebo, 120 mL of a commercial beverage (Be-light), or the corresponding HPF dose dissolved in 120 mL of Be-light. An oral glucose tolerance test (OGTT) (75 g glucose) was used to measure glucose tolerance before treatment (initial). A second OGTT was used to evaluate the acute effect of the HPF, and blood samples were collected at 0, 60, 120, and 150 min, and blood glucose levels were measured. Data were analyzed using a one-way ANOVA and paired Student's t-test.

Results

Participants with NGT: the D3 group showed a decrease in blood glucose area under the curve (AUC) when compared with the D1 group (13,639.2 ± 1585.9 vs. 16,756.6 ± 2709 mg · min/dL; P = 0.05). However, there was no difference with the placebo group (14,073.7 ± 1825.9 mg · min/dL, P = 0.9). When comparing the initial AUC vs. treatment AUC, the placebo, D2, and D3 groups decreased significantly (P = 0.01). Participants with prediabetes: the D3 group also show a significantly decreased in AUC when compared with the D2 group (19,815 ± 3153 vs. 27,545 ± 5398 mg · min/dL; P = 0.01). However, there was no difference with the placebo group (21,743.5 ± 4503 mg · min/dL, P = 0.8). Additionally, when comparing initial AUC vs. treatment AUC, only the D3 group decreased significantly (P = 0.01).

Conclusions

The comparison of the acute effect of three different doses of HPF showed a decrease in blood glucose (AUC) in a dose-dependent manner in participants with prediabetes.

Funding Sources

CONACYT Problemas Nacionales 2016-2081.

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.

Efecto de una intervención educativa en la hemoglobina capilar en una comunidad indígena de la Huasteca Potosina. Estudio piloto

Introducción: El objetivo de esta investigación fue evaluar el efecto de una intervención educativa contextualizada a los alimentos disponibles en una comunidad indígena de la Huasteca Potosina, sobre la hemoglobina capilar.Material y métodos: Se llevó a cabo un estudio cuasiexperimental pretest-postest de un solo grupo, de diciembre de 2014 a diciembre de 2015 en niños indígenas de 0 a 5 años, de la comunidad de Tocoy, San Antonio, San Luis Potosí, México. Se realizó una intervención de 6 meses y constó de talleres de educación nutricional los cuales incluían pláticas informativas, talleres de cocina y retroalimentación de los conocimientos impartidos. Se realizó una evaluación previa a la intervención y 4 meses posteriores a esta, en la que se valoró el estado nutricio (medidas antropométricas y concentración de hemoglobina capilar) y la ingesta de macro y micronutrimentos (recordatorios de 24 horas). Resultados: Se encontró un aumento en la concentración de hemoglobina capilar de 11,3±1,3 a 12,0±1,4 mg/dl (p=0,025) y la prevalencia de anemia disminuyó de 37 a 25.9%.Conclusiones: Una intervención educativa contextualizada a los alimentos disponibles en una comunidad puede contribuir a mejorar las concentraciones de hemoglobina capilar en niños menores de 5 años en una comunidad indígena de la Huasteca potosina.

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.

Use of Raman spectroscopy to screen diabetes mellitus with machine learning tools: reply to comment

We show the spectra of advanced glycation products in response to recent comments made by Bratchenko et al. Our results suggest that information retrieved by Raman spectroscopy is relevant to screening diabetic patients, however, the comparison carried out in our paper, between ANN and SVM, was not fair, because of the erroneous PCA selection procedure and different sources of variation present in the analysis.

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.

Use of Raman spectroscopy to screen diabetes mellitus with machine learning tools

Type 2 diabetes mellitus (DM2) is one of the most widely prevalent diseases worldwide and is currently screened by invasive techniques based on enzymatic assays that measure plasma glucose concentration in a laboratory setting. A promising plan of action for screening DM2 is to identify molecular signatures in a non-invasive fashion. This work describes the application of portable Raman spectroscopy coupled with several supervised machine-learning techniques, to discern between diabetic patients and healthy controls (Ctrl), with a high degree of accuracy. Using artificial neural networks (ANN), we accurately discriminated between DM2 and Ctrl groups with 88.9-90.9% accuracy, depending on the sampling site. In order to compare the ANN performance to more traditional methods used in spectroscopy, principal component analysis (PCA) was carried out. A subset of features from PCA was used to generate a support vector machine (SVM) model, albeit with decreased accuracy (76.0-82.5%). The 10-fold cross-validation model was performed to validate both classifiers. This technique is relatively low-cost, harmless, simple and comfortable for the patient, yielding rapid diagnosis. Furthermore, the performance of the ANN-based method was better than the typical performance of the invasive measurement of capillary blood glucose. These characteristics make our method a promising screening tool for identifying DM2 in a non-invasive and automated fashion.

[Malnutrition and program coverage, a pilot study in indigenous Tenek children in Tocoy, Mexico.]

[Not available]

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 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.

Development, relative validity, and reliability of a food frequency questionnaire for a case-control study on dietary advanced glycation end products and diabetes complications

Dietary advanced glycation end products (dAGEs) could be involved on diabetes complications, yet their quantification is not standardized. The objective of this study was to design a food frequency questionnaire (FFQ) for dAGEs, and to assess its reliability and validity. For the design, data from 30 subjects was used. The final instrument had 90 food items. To measure reliability and validity, 20 participants with type 2 diabetes filled out twice the FFQ (FFQ-T1, FFQ-T2) and 7-day food records (7-dFR). The Shrout-Fleiss coefficient was 0.98 showing good reliability. For validation, the results for the weighted kappa were 0.55 (moderate agreement) for FFQ-T1 and 0.64 (good agreement) for FFQ-T2, and 75% and 80% of subjects respectively were correctly classified into tertiles; Bland-Altman graphics showed no systematic bias. This FFQ is comparable to 7-dFR for measuring dAGEs. To our knowledge, this is the first questionnaire designed to measure specifically dAGEs.

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.

Dietary advanced glycation end products and aging

Advanced glycation end products (AGEs) are a heterogeneous, complex group of compounds that are formed when reducing sugar reacts in a non-enzymatic way with amino acids in proteins and other macromolecules. This occurs both exogenously (in food) and endogenously (in humans) with greater concentrations found in older adults. While higher AGEs occur in both healthy older adults and those with chronic diseases, research is progressing to both quantify AGEs in food and in people, and to identify mechanisms that would explain why some human tissues are damaged, and others are not. In the last twenty years, there has been increased evidence that AGEs could be implicated in the development of chronic degenerative diseases of aging, such as cardiovascular disease, Alzheimer’s disease and with complications of diabetes mellitus. Results of several studies in animal models and humans show that the restriction of dietary AGEs has positive effects on wound healing, insulin resistance and cardiovascular diseases. Recently, the effect of restriction in AGEs intake has been reported to increase the lifespan in animal models. This paper will summarize the work that has been published for both food AGEs and in vivo AGEs and their relation with aging, as well as provide suggestions for future research.