High intake of dietary advanced glycation end-products is associated with increased arterial stiffness and inflammation in subjects with type 2 diabetes

Plant-based diet and erectile dysfunction: a narrative review

Evidence shows that the consumption of plant foods, particularly those in their whole form (fruits, vegetables, whole grains, nuts, seeds, and legumes from which no edible part has been removed) improves cardiometabolic risk factors and is associated with reduced risk of cardiovascular diseases (CVDs), diabetes, cancer, chronic kidney disease and mortality compared to animal (meat, fish, eggs and dairy) and non-whole plant foods (sugar-sweetened beverages, refined grains, etc.). Erectile dysfunction (ED) is considered a strong predictor of CVD. The underlying defect in arteriogenic ED is endothelial dysfunction. A plant-based diet focused on whole plant foods could enhance penile erection as it improves endothelial function through various mechanisms. First, it provides nitrates, L-arginine, and L-citrulline, substrates for nitric oxide production. In addition, this diet lowers low-density-lipoprotein cholesterol (LDL-C), trimethylamine N-oxide (TMAO), postprandial triglycerides, advanced glycation end-product (AGEs), inflammation, and vasoconstrictors levels, contributing to higher nitric oxide concentrations, increased endothelial progenitor cells preservation and decreased arterial stiffness. This review explores the epidemiological evidence of a plant-based diet emphasizing whole plant foods on ED and the potential biological pathways involved.

Simultaneous determination of advanced glycation end products and heterocyclic amines in roast/grilled meat by UPLC-MS/MS

Advanced glycation end products (AGEs) and heterocyclic amines (HAs) are main harmful Maillard reaction products of meat products. Simultaneous quantification of both with high sensitivity, selectivity and accuracy remains a major challenge due to inconsistencies in their pre-treatment and instrumental methods and the different polarity of AGEs and HAs. We developed a method for the simultaneous determination of AGEs and HAs in roast/grilled meat by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) using dynamic multiple reaction monitoring (D-MRM). The instrument parameters and pre-treatment method were optimized to achieve reasonably good separation and high response for the 11 target analytes within 8 min. From 10 to 200 ng/mL, the limits of detection (LODs) and limits of quantitation (LOQs) ranged from 0.3 to 5.5 μg/L and 0.9 to 6.3 μg/L, respectively, and the correlation coefficient (R2) was >0.99. It was acceptable to recoveries, standard deviations (RSDs), and matrix effects. Six types of roast/grilled meat samples were then tested using the developed method.

Plant foods, healthy plant-based diets, and type 2 diabetes: a review of the evidence

Type 2 diabetes (T2D) is a metabolic chronic disease in which insulin resistance and insufficient insulin production lead to elevated blood glucose levels. The prevalence of T2D is growing worldwide, mainly due to obesity and the adoption of Western diets. Replacing animal foods with healthy plant foods is associated with a lower risk of T2D in prospective studies. In randomized controlled trials, the consumption of healthy plant foods in place of animal foods led to cardiometabolic improvements in patients with T2D or who were at high risk of the disease. Dietary patterns that limit or exclude animal foods and focus on healthy plant foods (eg, fruits, vegetables, whole grains, nuts, legumes), known as healthy, plant-based diets, are consistently associated with a lower risk of T2D in cohort studies. The aim of this review is to examine the differential effects of plant foods and animal foods on T2D risk and to describe the existing literature about the role of healthy, plant-based diets, particularly healthy vegan diets, in T2D prevention and management. The evidence from cohort studies and randomized controlled trials will be reported, in addition to the potential biological mechanisms that seem to be involved.

Intake of dietary advanced glycation end products may be associated with depression and sleep quality in young adults

BACKGROUND

This study examined the relationship between dietary intake of advanced glycation end products (dAGEs) and depression and sleep quality in young adults.

METHODS

This study, which included 420 university students (F = 80.2 %; M = 19.8 %), is observational and cross-sectional. Dietary AGEs intakes of individuals were taken with a 24-h food consumption record system. Measuring the depression status of the participants was evaluated with the Beck Depression Inventory (BDI), and the assessment of their sleep quality was evaluated with the Pittsburg Sleep Quality Index (PSQI). Individuals' dAGEs intakes were divided into three equal groups (low, medium, and high). The energy was adjusted in all analyzes of dAGEs intake. Study data were analyzed with the SPSS (27.0 version) and GraphPad program (8.0 version).

RESULTS

The BDI and PSQI total score averages of individuals in the high dAGEs intake group were higher than the other groups, and this difference was statistically significant (p < 0.001). There is no significant difference between individuals' dAGEs intakes and energy and macronutrient intakes. Students' dAGEs intake was affected by BDI (β = 0.722, 95 % Cl = 0.639;0.811) and PSQI (β = 0.286, 95 % Cl = 0.179;0.431) scores (p < 0.001). This effect persisted even when various confounding factors were included (age, gender, smoking, body mass index, chronic disease) (p < 0.001).

LIMITATIONS

These data are cross-sectional, which limits the generalizability of results and establishing cause-effect relationships.

CONCLUSION

There may be an association between dAGEs intake and the development of depression and sleep quality in young adults. Clinical intervention studies using objective measurement methods should be conducted on this issue in the future.

Evaluation of the effects of dietary advanced glycation end products on inflammation

Advanced glycation end products (AGEs) are a large number of heterogeneous compounds formed by the glycation of proteins, fats or nucleic acids. Endogenous AGEs have been associated with various health problems such as obesity, type 2 diabetes mellitus and cardiovascular disease. Inflammation is thought to be one of the main mechanisms in the development of these disorders. Although AGEs are produced endogenously in the body, exogenous sources such as smoking and diet also contribute to the body pool. Therefore, when the AGE pool in the body rises above physiological levels, different pathological conditions may occur through various mechanisms, especially inflammation. While the effects of endogenous AGEs on the development of inflammation have been studied relatively extensively, and current evidence indicates that dietary AGEs (dAGEs) contribute to the body's AGE pool, it is not yet known whether dAGEs have the same effect on the development of inflammation as endogenous AGEs. Therefore, this review aimed to evaluate the results of cross-sectional and intervention studies to understand whether dAGEs are associated with inflammation and, if there is an effect on inflammation, through which mechanisms this effect might occur.

Exploring the role of Maillard reaction and lipid oxidation in the advanced glycation end products of batter-coated meat products during frying

The Maillard reaction occurs during the frying of batter-coated meat products, resulting in the production of advanced glycosylation products that are harmful to human health. This study investigated the effects of frying temperature (140, 150, 160, 170 and 180 ℃) and time (80, 100, 120, 140 and 160 s) on the quality, advanced glycation end product (AGE) level and the relationship between these parameters in batter-coated meat products were investigated. The results showed that with an increase in frying temperature and time, the moisture content of the batter-coated meat products gradually decreased, the thiobarbituric Acid Reactive Substance (TBARS) values and oil content increased to 0.37 and 21.7 %, respectively, and then decreased, and CML and CEL content increased to 7.30 and 4.86 mg/g, respectively. Correlation analysis showed that the moisture content and absorbance at 420 nm, as well as TBARS values, were highly correlated with the oil content in batter-coated meat products. Additionally, the absorbance at 420 nm and TBARS levels were significantly correlated with AGE levels. Moreover, the AGE content in batter-coated meat products was less variable at lower frying temperatures or shorter frying times, and the influence of temperature on AGE formation was greater than that of time. Overall, these findings may help to better control the cooking conditions of batter-coated meat products based on AGE profiles.

Advanced-Glycation Endproducts: How cross-linking properties affect the collagen fibril behavior

Advanced-Glycation-Endproducts (AGEs) are known to be a major cause of impaired tissue material properties. In collagen fibrils, which constitute a major building component of human tissue, these AGEs appear as fibrillar cross-links. It has been shown that when AGEs accumulate in collagen fibrils, a process often caused by diabetes and aging, the mechanical properties of the collagen fibril are altered. However, current knowledge about the mechanical properties of different types of AGEs, and their quantity in collagen fibrils is limited owing to the scarcity of available experimental data. Consequently, the precise relationship between the nano-scale cross-link properties, which differ from type to type, their density in collagen fibrils, and the mechanical properties of the collagen fibrils at larger scales remains poorly understood. In our study, we use coarse-grained molecular dynamics simulations and perform destructive tensile tests on collagen fibrils to evaluate the effect of different cross-link densities and their mechanical properties on collagen fibril deformation and fracture behavior. We observe that the collagen fibril stiffens at high strain levels when either the AGEs density or the loading energy capacity of AGEs are increased. Based on our results, we demonstrate that this stiffening is caused by a mechanism that favors energy absorption via stretching rather than inter-molecular sliding. Hence, in these cross-linked collagen fibrils, the absorbed energy is stored rather than dissipated through friction, resulting in brittle fracture upon fibrillar failure. Further, by varying multiple AGEs nano-scale parameters, we show that the AGEs loading energy capacity is, aside from their density in the fibril, the unique factor determining the effect of different types of AGEs on the mechanical behavior of collagen fibrils. Our results show that knowing AGEs properties is crucial for a better understanding of the nano-scale origin of impaired tissue behavior. We further suggest that future experimental investigations should focus on the quantification of the loading energy capacity of AGEs as a key property for their influence on collagen fibrils.

Inflammation and oxidative stress markers in type 2 diabetes patients with Advanced Carotid atherosclerosis

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a major global health issue and a significant risk factor for atherosclerosis. Atherosclerosis in T2DM patients has been associated with inflammation, insulin resistance, hyperglycemia, dyslipidemia, and oxidative stress. Identifying molecular features of atherosclerotic plaques in T2DM patients could provide valuable insights into the pathogenesis of the disease.

METHODS

The MASCADI (Arachidonic Acid Metabolism in Carotid Stenosis Plaque in Diabetic Patients) study aimed to investigate the increase of 2-arachidonoyl-lysophatidylcholine (2-AA-LPC) in carotid plaques from T2DM and control patients and to explore its association with plaque vulnerability as well as with blood and intra-plaque biomarkers altered during diabetes.

RESULTS

In a population of elderly, polymedicated patients with advanced stage of atherosclerosis, we found that T2DM patients had higher systemic inflammation markers, such as high-sensitivity C-reactive protein (hsCRP) and IL-1β, higher levels of oxysterols, increased triglyceride levels, and decreased HDL levels as compared to control patients. Furthermore, 2-AA-LPC was significantly enriched in plaques from diabetic patients, suggesting its potential role in diabetic atherosclerosis. Interestingly, 2-AA-LPC was not associated with systemic markers related to diabetes, such as hsCRP, triglycerides, or HDL cholesterol. However, it was significantly correlated with the levels of inflammatory markers within the plaques such as lysophospholipids and 25-hydroxycholesterol, strengthening the link between local inflammation, arachidonic acid metabolism and diabetes.

CONCLUSION

Our study is in line with a key role for inflammation in the pathogenesis of diabetic atherosclerosis and highlights the involvement of 2-AA-LPC. Further research is needed to better understand the local processes involved in the alteration of plaque composition in T2DM and to identify potential therapeutic targets.

TRIAL REGISTRATION

The MASCADI was registered on ClinicalTrials.gov (clinical registration number: NCT03202823).

Advanced glycation end product signaling and metabolic complications: Dietary approach

Advanced glycation end products (AGEs) are a heterogeneous collection of compounds formed during industrial processing and home cooking through a sequence of nonenzymatic glycation reactions. The modern western diet is full of heat-treated foods that contribute to AGE intake. Foods high in AGEs in the contemporary diet include processed cereal products. Due to industrialization and marketing strategies, restaurant meals are modified rather than being traditionally or conventionally cooked. Fried, grilled, baked, and boiled foods have the greatest AGE levels. Higher AGE-content foods include dry nuts, roasted walnuts, sunflower seeds, fried chicken, bacon, and beef. Animal proteins and processed plant foods contain furosine, acrylamide, heterocyclic amines, and 5-hydroxymethylfurfural. Furosine (2-furoil-methyl-lysine) is an amino acid found in cooked meat products and other processed foods. High concentrations of carboxymethyl-lysine, carboxyethyl-lysine, and methylglyoxal-O are found in heat-treated nonvegetarian foods, peanut butter, and cereal items. Increased plasma levels of AGEs, which are harmful chemicals that lead to age-related diseases and physiological aging, diabetes, and autoimmune/inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis. AGEs in the pathophysiology of metabolic diseases have been linked to individuals with diabetes mellitus who have peripheral nerves with high amounts of AGEs and diabetes has been linked to increased myelin glycation. Insulin resistance and hyperglycemia can impact numerous human tissues and organs, leading to long-term difficulties in a number of systems and organs, including the cardiovascular system. Plasma AGE levels are linked to all-cause mortality in individuals with diabetes who have fatal or nonfatal coronary artery disease, such as ventricular dysfunction. High levels of tissue AGEs are independently associated with cardiac systolic dysfunction in diabetic patients with heart failure compared with diabetic patients without heart failure. It is widely recognized that AGEs and oxidative stress play a key role in the cardiovascular complications of diabetes because they both influence and are impacted by oxidative stress. All chronic illnesses involve protein, lipid, or nucleic acid modifications including crosslinked and nondegradable aggregates known as AGEs. Endogenous AGE formation or dietary AGE uptake can result in additional protein modifications and stimulation of several inflammatory signaling pathways. Many of these systems, however, require additional explanation because they are not entirely obvious. This review summarizes the current evidence regarding dietary sources of AGEs and metabolism-related complications associated with AGEs.

Are dietary and serum advanced glycation end-products related to inflammation and oxidation biomarkers in breast cancer patients: a follow-up study

PURPOSE

This study is aimed at evaluating the relationship between dietary and serum advanced glycation end-products (AGEs) with serum inflammatory and oxidative stress biomarkers in breast cancer (BC).

METHODS

A sample of BC patients was followed for 12 months (March 2020-January 2022). Three-day food consumption record and serum samples were taken before surgery (T1), before chemotherapy (T2), at the 6^th month of chemotherapy (T3), and at the 12^th month of chemotherapy (T4). Dietary AGE intake was represented by carboxymethyl lysine (dCML). Serum levels of CML, inflammation, and oxidation biomarkers were determined with biochemical blood tests. The results were compared according to human epidermal growth factor receptor-2 (HER2) status.

RESULTS

Thirty-two women with BC and 32 age and body mass index-matched healthy women participated. No significant correlation was found between dCML and serum CML, inflammatory or oxidative stress biomarkers at T1, T2, and T4. A weak positive correlation was demonstrated between dCML and serum malondialdehyde levels (rho=0.355, p=0.046) at T3. The serum CML, inflammation, and oxidation biomarker levels of the HER2- group were significantly higher than those of the HER2+ group at T1.

CONCLUSION

This study suggests that there is limited correlation between dCML and serum inflammation and oxidative stress biomarkers in BC patients. Inflammation and oxidative biomarker levels appear to decline with treatment although dietary and serum AGE levels show not a corresponding significant decline. The HER2- subtype appears to be associated with higher dietary and serum AGEs and higher inflammatory and oxidative stress biomarkers.

Insight into the effect of traditional frying techniques on glycosylated hazardous products, quality attributes and flavor characteristics of grass carp fillets

This study aimed to evaluate the evolution of quality attributes, oxidation index, glycosylated hazardous products, aroma characteristics of grass carp fillets and their relationship under air-frying, roast-frying and pan-frying. With frying progressed, the level of carbonyl protein and lipid oxidation products increased significantly (following air-frying > pan-frying > roast-frying), and the latter decreased subsequently after 6 min. Fillets possessed by frying increased significantly N^ε-carboxymethyl-lysines (CML) and 5-hydroxymethylfurfural (5-HMF) levels, whose increment was pan-frying > air-frying > roast-frying. Compared to raw, eighty-seven volatiles were identified and the total concentrations of those increased gradually in air-frying, but then decreased up to 6 min in roast-frying and pan-frying. Furthermore, significant correlations between CML, TBARS and 5-HMF, quality attributes, oxidation index; volatiles (VIP and/or OAV > 1) and lipid oxidation index were obtained. Conclusively, fillets possessed by air-/roast-frying showed more lipid oxidation and alcohols/aldehydes, while pan-fried enriched CML and pyrazines.

Dietary Advanced Glycation End Products and Risk of Overall and Cause-Specific Mortality: Results from the Golestan Cohort Study

Controversy exists regarding the association of dietary advanced glycation end products (dAGEs) with the risk of disease outcomes and mortality. We aimed to examine, prospectively, the association between dAGEs intake and the risk of overall and cause-specific mortality in the Golestan Cohort Study. The cohort was conducted between 2004 and 2008 in Golestan Province (Iran) recruiting 50,045 participants aged 40-75 years. Assessment of dietary intake over the last year was performed at baseline using a 116-item food frequency questionnaire. The dAGEs values for each individual were calculated based on published databases of AGE values of various food items. The main outcome was overall mortality at the time of follow-up (13.5 years). Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and cause-specific mortality were estimated according to the dAGEs quintiles. During 656, 532 person-years of follow-up, 5406 deaths in men and 4722 deaths in women were reported. Participants at the highest quintile of dAGE had a lower risk of overall mortality (HR: 0.89, 95% CI: 0.84, 0.95), CVD mortality (HR: 0.89, 95% CI: 0.84, 0.95), and death from other causes (HR: 0.89, 95% CI: 0.84, 0.95) compared to those in the first quintile after adjusting for confounders. We found no association of dAGEs with risk of mortality from cancer (all), respiratory and infectious diseases, and injuries. Our findings do not confirm a positive association between dAGEs and the risk of mortality in Iranian adults. There is still no agreement among studies investigating dAGEs and their health-related aspects. So, further high-quality studies are required to clarify this association.

Are We What We Eat? The Moral Imperative of the Medical Profession to Promote Plant-Based Nutrition

The typical Western diet, high in processed and animal-based foods, is nutritionally and ethically problematic. Beyond the well-documented cruelty to animals that characterizes the practices of the factory-farming industry, current patterns of meat consumption contribute to medical and moral harm in humans on both an individual level and a public health scale. We aim to deconstruct, by highlighting their fallacies, the common positive and normative arguments that are used to defend current nutritional patterns. Animal-based foods promote the mechanisms that underlie chronic cardiometabolic disease, whereas whole-food plant-based nutrition can reverse them. Factory farming of animals also contributes to climate change, antibiotic resistance, and the spread of infectious diseases. Finally, the current allocation of nutritional resources in the United States is unjust. A societal shift toward more whole-food plant-based patterns of eating stands to provide significant health benefits and ethical advantages, and the medical profession has a duty to advocate accordingly. Although it remains important for individuals to make better food choices to promote their own health, personal responsibility is predicated on sound advice and on resource equity, including the availability of healthy options. Nutrition equity is a moral imperative and should be a top priority in the promotion of public health.

A comparison of principal component analysis, partial least-squares, and reduced-rank regressions in the identification of dietary patterns associated with hypertension: YaHS-TAMYZ and Shahedieh cohort studies

Limited data exist on the advantage of data reduction hybrid methodologies for evaluating the relationship between dietary patterns (DPs) and chronic diseases and they have led to inconsistent results. This study aimed to investigate the association between DPs extracted using principal component analysis (PCA), partial least-squares (PLS), and reduced-rank regressions (RRRs) in identifying DPs associated with hypertension (HTN) risk. The current study was conducted in the context of two cohort studies accomplished in Iran. DPs were generated using PCA, PLS, and RRR methods. Log-binomial logistic regression test was used to assess the association between DPs and the risk of HTN. From a total of 12,403 included participants aged 20-70 years, 507 incident cases of confirmed HTN were identified. The PCA-DP2 was associated with HTN in the fully adjusted model (T3 vs. T1: RR: 0.737, 95% CI: 0.57-0.93, P trend = 0.013). The PLS-DP2 and HTN risk were inversely associated in the multivariate model (T3 vs. T1: RR: 0.704, 95% CI: 0.54-0.91, P trend = 0.013). The RRR-DP2 was associated with an increased risk of HTN (T3 vs. T1: RR: 1.412, 95% CI: 1.11-1.80, P trend = 0.007). Our findings suggest that the RRR method reveals stronger results in association with HTN risk. However, further investigations are required to confirm the association between DPs derived by PLS and RRR methods by incorporating biomarkers related to HTN as the response variables.

Inflammation level in type 2 diabetes is associated with dietary advanced glycation end products, Mediterranean diet adherence and oxidative balance score: A pathway analysis

AIMS

The aim of this study was to evaluate the effects of dietary advanced glycation end products (dAGE) intake, Mediterranean diet adherence screener (MEDAS), and oxidative balance score (OBS) on inflammation among individuals with type 2 diabetes.

METHODS

The study was conducted with 96 adults (aged between 32 and 64 years) with type 2 diabetes. The average daily dAGE intakes, energy and macronutrient intakes of the participants were taken with the three-day food consumption recording method. OBS and MEDAS score was used. At the same time, routine blood lipids, HbA1c, fasting blood glucose and inflammation marker C-reactive protein (CRP) were measured.

RESULTS

Dietary AGE intake was associated with fasting blood glucose, HbA1c, CRP and blood pressures (p < 0.01). The relationship between OBS and dAGE intake was significant (β = -0.36; 95 % Cl = -0.500, -0.220; p < 0.001). MEDAS has a negative and statistically significant effect on dAGE intake (β = -0.56; 95 % Cl = -0.696, -0.444; p < 0.001). There was a significant and positive effect of dAGE on CRP when other variables (MEDAS, OBS) affecting dAGE were also included in the analysis (β = 0.79; 95 % CI = 0.664, 0.917; p < 0.001).

CONCLUSIONS

Our findings may have important implications for explaining the development of inflammation in type 2 diabetes patients with high dAGE intake.

Relação dos produtos finais de glicação avançada na hipertensão de pacientes com diabetes: uma revisão sistemática

Resumo Diabetes mellitus e hipertensão arterial estão entre os cinco fatores de risco que elevam a mortalidade no mundo. Ambas são doenças crônicas não transmissíveis (DCNT) que têm associação fisiopatológica. Os produtos finais de glicação avançada (AGEs), produzidos pela falta de controle glicêmico nos pacientes diabéticos, interagem com seus receptores para AGEs (RAGE) resultando no aumento da rigidez arterial e da inflamação e em alterações endoteliais, fatores que intensificam o risco do desenvolvimento da hipertensão e de demais complicações. Realizou-se uma revisão sistemática nas bases de dados Pubmed, SciELO, Cochrane Library e Web of Science utilizando descritores e operadores booleanos para otimizar a busca, com o objetivo de fornecer o mecanismo da glicação não enzimática de proteínas presente em pacientes com diabetes e sua correlação com o aparecimento da hipertensão, expondo todo o dano endotelial e celular ocasionado pelos AGEs. Foram encontrados 719 artigos, dos quais 99 foram lidos na íntegra, e 26 atenderam aos critérios de elegibilidade e foram incluídos na presente revisão. Os AGEs devem ser considerados um dos principais fatores de risco cardiometabólico. A redução da interação AGE-RAGE resultará na proteção cardiovascular e no aumento da expectativa de vida.

Possible effects of dietary advanced glycation end products on maternal and fetal health: a review

Excessive accumulation of advanced glycation end products (AGEs) in the body has been associated with many adverse health conditions. The common point of the pathologies associated at this point is oxidative stress and inflammation. Pregnancy is an important period in which many physiological, psychological, and biological changes are experienced. Along with the physiological changes that occur during this period, the mother maintaining an AGE-rich diet may cause an increase in the body's AGE pool and may increase oxidative stress and inflammation, as seen in healthy individuals. Studies have reported the negative effects of maternal AGE levels on maternal and fetal health during pregnancy. Although gestational diabetes, preeclampsia, endothelial dysfunction, and pelvic diseases constitute maternal complications, a number of pathological conditions such as intrauterine growth retardation, premature birth, neural tube defect, neurobehavioral developmental disorders, fetal death, and neonatal asphyxia constitute fetal complications. It is thought that the mechanisms of these complications have not been confirmed yet and more clinical studies are needed on this subject. The possible effects of dietary AGE levels during pregnancy on maternal and fetal health are examined in this review.

The Effects of Dietary Advanced Glycation End-Products on Neurocognitive and Mental Disorders

Advanced glycation end products (AGEs) are glycated proteins or lipids formed endogenously in the human body or consumed through diet. Ultra-processed foods and some culinary techniques, such as dry cooking methods, represent the main sources and drivers of dietary AGEs. Tissue accumulation of AGEs has been associated with cellular aging and implicated in various age-related diseases, including type-2 diabetes and cardiovascular disease. The current review summarizes the literature examining the associations between AGEs and neurocognitive and mental health disorders. Studies indicate that elevated circulating AGEs are cross-sectionally associated with poorer cognitive function and longitudinally increase the risk of developing dementia. Additionally, preliminary studies show that higher skin AGE accumulation may be associated with mental disorders, particularly depression and schizophrenia. Potential mechanisms underpinning the effects of AGEs include elevated oxidative stress and neuroinflammation, which are both key pathogenetic mechanisms underlying neurodegeneration and mental disorders. Decreasing dietary intake of AGEs may improve neurological and mental disorder outcomes. However, more sophisticated prospective studies and analytical approaches are required to verify directionality and the extent to which AGEs represent a mediator linking unhealthy dietary patterns with cognitive and mental disorders.

Dietary Advanced Glycation End-Products Affects the Progression of Early Diabetes by Intervening in Carbohydrate and Lipid Metabolism

SCOPE

Epidemiologic studies indicate significant contributions of thermally processed diets to the risk for diabetes and its related renal complications, but the mechanisms relating diet to disease remain unclear. This study evaluates the effects of the diet differ only in the content of advanced glycation end-products (AGEs) on early diabetes in Lepr^db/db mice.

METHODS AND RESULTS

High AGEs diet (60 mg CML per kg protein) is fed to mice for 8 weeks. Dietary AGEs associated with diabetic features, including hyperglycemia, insulin resistance, and increased mRNA expression of renal chemokines, CCL3 and CXC3L1 are found. Untargeted metabolomics reveal that the high AGEs diet inhibits carbohydrate catabolism and promotes lipid anabolism. Additionally, the high AGEs diet alters the composition of the gut microbiota and indirectly affects the carbohydrate metabolism by altering the plasma levels of glyceraldehyde and pyruvate. However, switching to the lower AGEs diet can relieve most of the symptoms except microbiota composition.

CONCLUSION

The results indicate that dietary AGEs exposure intervenes in the development of diabetes through modulating the carbohydrate and lipid metabolism, and critically, switching to the lower AGEs diet arrested or reversed diabetes progression. A light-processing dietary intervention that helps to arrest early diabetes is suggested.

Observational and Genetic Associations of Modifiable Risk Factors with Aortic Valve Stenosis: A Prospective Cohort Study of 0.5 Million Participants

Background: Observational studies have shown that modifiable risk factors are associated with aortic valve stenosis (AVS). However, the causality behind these associations remains largely unknown. Objectives: To explore the associations of modifiable risk factors, including metabolic factors, biochemical measures, education, and lifestyles with AVS and their potential causal associations. Methods: We enrolled 361,930 British white people with genetic data in the UK biobank. Cox proportional risk regression models were used to estimate the hazard ratios between 28 modifiable risk factors and AVS. We used genetic instruments for modifiable risk factors to determine the potential causal relationships using a one-sample Mendelian randomization (MR) approach. Results: A total of 1602 participants developed AVS during an 8.4-year follow-up. Observational analyses showed higher adiposity, blood pressure, heart rate, low-density lipoprotein, urate, C-reactive protein, creatinine, albumin, and glycated hemoglobin, but lower serum vitamin D, and education, unhealthy lifestyle, and poor sleep quality were related to a higher risk of AVS after adjusting for the Bonferroni correction (p < 0.0013). Genetically predicted 1-SD higher levels of body mass index [HR: 1.09, 95% CI: 1.03 to 1.16], body fat percentage (1.17, 1.03 to 1.33), triglyceride (TG) [1.08, 1.00 to 1.16], low-density lipoprotein (LDL) (1.15, 1.08 to 1.21) and serum total cholesterol (TC) (1.13, 1.02 to 1.25) were associated with a higher risk of AVS, respectively. Genetically determined per category higher insomnia (1.32, 1.13 to 1.55) was also associated with AVS. The abovementioned genetic associations with the incident AVS showed an increasing relationship pattern. Conclusions: This study provides strong evidence for the potential causal roles of cardiometabolic factors in developing AVS, highlighting that an idea of metabolic status through a healthy lifestyle may help prevent AVS.

Correlation between the accumulation of skin glycosylation end products and the development of type 2 diabetic peripheral neuropathy

BACKGROUND

The accumulation of advanced glycation end products (AGEs) occurring in skin tissues can be measured by AGE Reader. Here, we assessed the correlation between AGEs values and the development of type 2 diabetic peripheral neuropathy (DPN).

METHODS

The basic clinical information of 560 patients with T2DM was collected through an electronic system. AGEs and diabetic complication risk score was measured by AGE Reader, a non-invasive optical signal detector. All of the participants were classified into 4 groups based on Dyck criteria: grade 0 (non-DPN group), grade 1 (early stage group), grade 2 (middle stage group) and grade 3 (advanced group). Pearson correlation analysis and Spearman correlation analysis were used to evaluate the correlation between AGEs and other indexes. The sensitivity and specificity of glycosylated products were evaluated by ROC curve.

RESULTS

With the increase of DPN severity, the accumulative AGEs showed an increasing trend. Significant differences (P = 0.000) of AGEs were found among grades 0, 1, 2, and 3 of DPN, and significant differences (P = 0.000) of AGEs were found between grades 1 and 3. There were significant differences in DPN risk score between grades 0, 1, 2, and 3, between grades 1, 2, and 3, and between grades 2 and 3 (P < 0.01 or P < 0.05). AGEs were positively correlated with age, blood uric acid, disease course, systolic blood pressure, the risk scores of the four major complications of diabetes, renal function indicators (serum creatinine, Cystatin C, homocysteine, the ratio of urinary albumin and creatinine, urinary microalbumin, α-microglobulin, urinary transferrin, urinary immunoglobulin), inflammatory indicators (white blood cell count, neutrophil count, neutrophil-to-lymphocyte ratio, C-reactive protein), and TCSS score. However, it was negatively correlated with BMI,fasting insulin, insulin 1-3 h postprandial, lymphocyte count, HOMA insulin resistance index and estimated glomerular filtration rate. The area under the AGEs cumulant and neuropathy risk score curve was 0.769 and 0.743, respectively. The confidence intervals were (71.2-82.6%) and (68.8-79.9%), respectively. The maximum Youden's index of AGEs cumulant was 0.440, and the corresponding AGEs cumulant value was 77.65. The corresponding sensitivity and specificity were 0.731 and 0.709, respectively. Furthermore, the maximum Youden's index of neuropathy risk score was 0.385, and the corresponding neuropathy risk score was 66.25. The corresponding sensitivity and the specificity were 0.676 and 0.709, respectively.

CONCLUSION

The cumulative amount of skin AGEs can be used as the diagnostic index and the prediction and evaluation index of DPN severity. Moreover, the diabetic peripheral neuropathy risk score can predict the risk of DPN in patients with T2DM.

Food obesogens as emerging metabolic disruptors; A toxicological insight

Human food is composed of loads of chemicals derived naturally as well as unintentionally through environmental sources. Food additives added purposefully, play an important role in the palatability of foods. Most additives are synthetic whose essentiality in food processing is well-known however their health risks are not overlooked. The palatability of food should not only stimulate our eating desire alone but, also assure sufficient quality and safety. Application of food additives varies from region to region due to cultural or ethnic differences and the local food availability. There are about more than ten thousand chemicals allowed in food whereas due to weak enforcement, it becomes onerous for regulatory bodies identifying chemicals that are inadequately or not tested at all for safety. The hiking population and urbanization in many industrialized and developing countries resulted in life-style changes including culinary and eating choices. Particularly, the modern way of this globalised life demands ready-to-cook or ready-made foods, snacks, sweets, soft drinks, desserts, confectionery and so on. These sorts of food would be most uninteresting unless processed with additives. This puts food industries under demand to robustly supply foods that are either partially, fully or ultra-processed using plenty of additives. Recent research warns consuming food additives may result in serious health risks, not only for children but also for adults. Growing body of studies on food additives in various experimental animals, cell cultures, and human population suggest elevation of number of obesity and diabetes risk factors i.e. adiposity, dyslipidemia, weight gain, hyperglycaemia, insulin resistance, glucose intolerance, energy imbalance, hormonal intervention etc. Hence, it is important to identify and explore food obesogens or obesogenic food additives posing potential impact. Based on the recent toxicological findings, the review aspires to establish the association between exposure of food obesogen and metabolic disruption which may help filling knowledge gaps and distributing more knowledge, awareness and effective measures to implement treatment and preventive strategies for metabolic syndrome.

Receptor Mediated Effects of Advanced Glycation End Products (AGEs) on Innate and Adaptative Immunity: Relevance for Food Allergy

As of late, evidence has been emerging that the Maillard reaction (MR, also referred to as glycation) affects the structure and function of food proteins. MR induces the conformational and chemical modification of food proteins, not only on the level of IgG/IgE recognition, but also by increasing the interaction and recognition of these modified proteins by antigen-presenting cells (APCs). This affects their biological properties, including digestibility, bioavailability, immunogenicity, and ultimately their allergenicity. APCs possess various receptors that recognize glycation structures, which include receptor for advanced glycation end products (RAGE), scavenger receptors (SRs), galectin-3 and CD36. Through these receptors, glycation structures may influence the recognition, uptake and antigen-processing of food allergens by dendritic cells (DCs) and monocytes. This may lead to enhanced cytokine production and maturation of DCs, and may also induce adaptive immune responses to the antigens/allergens as a result of antigen uptake, processing and presentation to T cells. Here, we aim to review the current literature on the immunogenicity of AGEs originating from food (exogenous or dietary AGEs) in relation to AGEs that are formed within the body (endogenous AGEs), their interactions with receptors present on immune cells, and their effects on the activation of the innate as well as the adaptive immune system. Finally, we review the clinical relevance of AGEs in food allergies.

Maillard reaction harmful products in dairy products: Formation, occurrence, analysis, and mitigation strategies

Various harmful Maillard reaction products such as lactulosyl-lysine (furosine), furfurals, and advanced glycation end products (AGEs) could be formed during the thermal processing of dairy products, which could lead to various chronic diseases. In this review, the furosine, furfurals, and AGEs formation, occurrence, analysis methods, and toxicological and health aspects in various dairy products were summarized to better monitor and control the levels of harmful Maillard reaction products in processed dairy products. It was observed that all types of dairy products, including raw milk, contain harmful Maillard reaction products, with the highest in whey cheese and condensed milk. High-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the common method for the determination of furosine and furfurals and AGEs in dairy products, respectively. However, the simple, rapid, environment-friendly, and accurate methods of determination are still to be developed. Incorporating resveratrol, pectin oligosaccharides (POS) in milk are effective methods to inhibit AGEs formation. This review provides a guide not only for consumers regarding the selection and consumption of dairy products, but also for monitoring and controlling the quality of dairy products.

Relationship of advanced glycation end-products in hypertension in diabetic patients: a systematic review

Diabetes mellitus and arterial hypertension are among the five risk factors that increase mortality in the world. Both are chronic, non-communicable diseases (NCDs), that have a pathophysiological association. Advanced glycation end products (AGEs), produced by the lack of glycemic control in diabetic patients, interact with their AGE receptors (AGER) resulting in increased arterial stiffness, inflammation and endothelial changes - which increases the risk of developing hypertension and other complications. We ran a systematic review in Pubmed, SciELO, Cochrane Library and Web of Science databases using keywords and Boolean operators to optimize the search, with the objective of assessing the mechanism of non-enzymatic glycation of proteins present in patients with diabetes and its correlation with the onset of hypertension, exposing all the endothelial and cellular damage caused by AGEs. We found 719 papers, of which 99 were read in full, and 26 met the eligibility criteria and were included in the present review. AGEs should be considered one of the main cardiometabolic risk factors. Reducing the AGE-AGER interaction will result in cardiovascular protection and increased life expectancy.

Dietary Intake of Advanced Glycation End Products (AGEs) and Mortality among Individuals with Colorectal Cancer

Advanced glycation end-products (AGEs) may promote oxidative stress and inflammation and have been linked to multiple chronic diseases, including cancer. However, the association of AGEs with mortality after colorectal cancer (CRC) diagnosis has not been previously investigated. Multivariable Cox proportional hazards models were used to calculate hazard ratios and corresponding 95% confidence intervals for associations between dietary intake of AGEs with CRC-specific and all-cause mortality among 5801 participant cases diagnosed with CRC in the European Prospective Investigation into Cancer and Nutrition study between 1993 and 2013. Dietary intakes of AGEs were estimated using country-specific dietary questionnaires, linked to an AGE database, that accounted for food preparation and processing. During a median of 58 months of follow-up, 2421 cases died (1841 from CRC). Individually or combined, dietary intakes of AGEs were not associated with all-cause and CRC-specific mortality among cases. However, there was a suggestion for a positive association between AGEs and all-cause or CRC-specific mortality among CRC cases without type II diabetes (all-cause, Pinteraction = 0.05) and CRC cases with the longest follow-up between recruitment and cancer diagnosis (CRC-specific, Pinteraction = 0.003; all-cause, Pinteraction = 0.01). Our study suggests that pre-diagnostic dietary intakes of AGEs were not associated with CRC-specific or all-cause mortality among CRC patients. Further investigations using biomarkers of AGEs and stratifying by sex, diabetes status, and timing of exposure to AGEs are warranted.

Does dietary fat affect advanced glycation end products and their receptors? A systematic review of clinical trials

CONTEXT

Dietary fat seems to affect advanced glycation end products (AGEs) and their receptors. This systematic review assesses studies that evaluated the effect of dietary fat on markers of glycation.

OBJECTIVE

The aim of this systematic review was to analyze the effect of dietary fat on markers of glycation and to explore the mechanisms involved.

DATA SOURCES

This study was conducted according to PRISMA guidelines. PubMed, Cochrane, and Scopus databases were searched, using descriptors related to dietary fat, AGEs, and the receptors for AGEs.

STUDY SELECTION

Studies were selected independently by the 3 authors. Divergent decisions were resolved by consensus. All studies that evaluated the effects of the quantity and quality of dietary fat on circulating concentrations of AGEs and their receptors in adults and elderly adults with or without chronic diseases were included. Initially, 9 studies met the selection criteria.

DATA EXTRACTION

Three authors performed data extraction independently. Six studies were included.

RESULTS

Consumption of a Mediterranean diet rich in monounsaturated fatty acids (MUFAs) and low in dietary AGEs reduced serum concentrations of AGEs, reduced expression of the receptor for AGE (RAGE), and increased expression of the AGE receptor 1 (AGER1) when compared with consumption of a Western diet rich in saturated fatty acids and dietary AGEs. Supplementation with omega-3 polyunsaturated fatty acids (PUFAs) resulted in decreased concentrations of fluorescent AGEs and decreased expression of RAGE as well as increased expression of AGER1.

CONCLUSIONS

Increased consumption of MUFAs and omega-3 PUFAs and reduced consumption of saturated fatty acids seem to be effective strategies to beneficially affect glycation markers, which in turn may prevent and control chronic diseases.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42021220489.

Advanced glycation end products via skin autofluorescence as potential marker of carotid atherosclerosis in patients with type 2 diabetes

BACKGROUND AND AIMS

Advanced glycation end products (AGEs) are reported to be correlated with diabetic vascular complications. This study aimed to investigate the association between AGEs and carotid atherosclerosis (CAS) as a surrogate marker of cardiovascular disease (CVD).

METHODS AND RESULTS

A total of 1006 patients with type 2 diabetes were included. CAS was defined as the presence of carotid arterial atherosclerotic plaque in any of bilateral carotid artery segments measured by ultrasonography. AGEs were measured by the noninvasive skin autofluorescence method. AGE_age index was calculated as AGEs × age/100. Patients with CAS showed a significantly higher AGE_age (P < 0.01), and the prevalence of CAS increased with ascending AGE_age levels (P for trend < 0.001). Logistic regression analysis revealed that AGE_age was significantly positively associated with odds of CAS, and the odds ratios of the presence of CAS across quartiles of AGE_age were 1.00, 3.00 [95% confidence interval (CI) 1.90-4.74], 4.04 (95%CI 2.50-6.53) and 4.99 (95%CI 2.97-8.40) for the multivariable-adjusted model (P for trend <0.001), respectively. In the fully adjusted model, each 5.0 increase in AGE_age was associated with a 0.019 mm increment in carotid intima-media thickness. Furthermore, AGE_age presented an acceptable predictive value for CAS, with an optimal cutoff point of 43.2, and the sensitivity, specificity and area under the curve (AUC) were 74.5% (95%CI 70.7-78.1%), 61.9% (95%CI 57.2-66.4%) and 0.735 (0.706-0.762), respectively.

CONCLUSION

AGE_age, the noninvasive measurement of AGEs combined with age is a promising approach for triaging patients at high risk of CVDs.

High glomerular filtration rate is associated with impaired arterial stiffness and subendocardial viability ratio in prediabetic subjects

BACKGROUND AND AIMS

High glomerular filtration rate (HGFR) is associated with cardiovascular damage in the setting of various conditions such as obesity and diabetes. Prediabetes was also associated with increased GFR, however, the association between prediabetes, HGFR and cardiovascular damage has not been investigated. In this study, we investigated the association between HGFR and early markers of cardiovascular disease in subjects with prediabetes.

METHODS AND RESULTS

Augmentation pressure (Aug), augmentation index (AIx), subendocardial viability ratio (SEVR), pulse wave velocity (PWV), intima-media thickness (IMT) and estimated GFR (eGFR) were evaluated in 230 subjects with prediabetes. The eGFR was assessed using the Chronic Kidney Disease Epidemiology Collaboration formula. HGFR was defined as an eGFR above the 75th percentile. Prediabetic subjects were divided into two groups according to presence/absence of HGFR: 61 subjects with HGFR and 169 subjects without HGFR. Subjects with HGFR showed higher Aug, AIx and lower SEVR compared with prediabetic subjects with lower eGFR (14.1 ± 7.2 vs 10.8 ± 6.2, 32.9 ± 12.7 vs 27.6 ± 11.7, 153.5 ± 27.8 vs 162 ± 30.2, p < 0.05). No differences were found in PWV and IMT values between the two groups. Then, we performed multiple regression analysis to test the relationship between Aug, SEVR and several cardiovascular risk factors. In multiple regression analysis Aug was associated with age, systolic blood pressure (BP), HOMA-IR and eGFR; the major determinants of SEVR were systolic BP, HOMA-IR and eGFR.

CONCLUSION

Subjects with prediabetes and HGFR exhibited an increased Aug, AIx and a reduced SEVR. These alterations are associated with eGFR, insulin resistance and systolic BP.

Aortic Stiffness: Epidemiology, Risk Factors, and Relevant Biomarkers

Aortic stiffness (AoS) is a maladaptive response to hemodynamic stress and both modifiable and non-modifiable risk factors, and elevated AoS increases afterload for the heart. AoS is a non-invasive marker of cardiovascular health and metabolic dysfunction. Implementing AoS as a diagnostic tool is challenging as it increases with age and varies amongst races. AoS is associated with lifestyle factors such as alcohol and smoking, as well as hypertension and comorbid conditions including metabolic syndrome and its components. Multiple studies have investigated various biomarkers associated with increased AoS, and this area is of particular interest given that these markers can highlight pathophysiologic pathways and specific therapeutic targets in the future. These biomarkers include those involved in the inflammatory cascade, anti-aging genes, and the renin-angiotensin aldosterone system. In the future, targeting AoS rather than blood pressure itself may be the key to improving vascular health and outcomes. In this review, we will discuss the current understanding of AoS, measurement of AoS and the challenges in interpretation, associated biomarkers, and possible therapeutic avenues for modulation of AoS.

Diet-Derived Advanced Glycation End Products (dAGEs) Induce Proinflammatory Cytokine Expression in Cardiac and Renal Tissues of Experimental Mice: Protective Effect of Curcumin

The beneficial effect of curcumin (CU) on dietary AGEs (dAGEs) involves blocking the overexpression of proinflammatory cytokine genes in the heart and kidney tissues of experimental mice. The animals were divided into six groups (n = 6/group) and were fed a heat-exposed diet (dAGEs) with or without CU for 6 months. Their blood pressure (BP) was monitored by a computerized tail-cuff BP-monitoring system. The mRNA and protein expression levels of proinflammatory genes were analyzed by RT-PCR and western blot, respectively. A marked increase in BP (108 ± 12 mmHg vs 149 ± 15 mmHg) accompanied by a marked increase in the heart and kidney weight ratio was noted in the dAGE-fed mice. Furthermore, the plasma levels of proinflammatory molecules (C5a, ICAM-1, IL-6, MCP-1, IL-1β and TNF-α) were found to be elevated (3-fold) in dAGE-fed mice. mRNA expression analysis revealed a significant increase in the expression levels of inflammatory markers (Cox-2, iNOS, and NF-κB) (3-fold) in cardiac and renal tissues of dAGE-fed mice. Moreover, increased expression of RAGE and downregulation of AGER-1 (p < 0.001) were noticed in the heart and kidney tissues of dAGE-fed mice. Interestingly, the dAGE-induced proinflammatory genes and inflammatory responses were neutralized upon cotreatment with CU. The present study demonstrates that dietary supplementation with CU has the ability to neutralize dAGE-induced adverse effects and alleviate proinflammatory gene expression in the heart and kidney tissues of experimental mice.

The Putative Role of Methylglyoxal in Arterial Stiffening: A Review

BACKGROUND

Arterial stiffening is a hallmark of vascular ageing and a consequence of many diseases including diabetes mellitus. Methylglyoxal (MGO), a highly reactive α-dicarbonyl mainly formed during glycolysis, has emerged as a potential contributor to the development of arterial stiffness. MGO reacts with arginine and lysine residues in proteins to form stable advanced glycation endproducts (AGEs). AGEs may contribute to arterial stiffening by increased cross-linking of collagen within the extracellular matrix (ECM), by altering the vascular structure, and by triggering inflammatory and oxidative pathways. Although arterial stiffness is mainly determined by ECM and vascular smooth muscle cell function, the effects of MGO and MGO-derived AGEs on these structures have not been thoroughly reviewed to date.

METHODS AND RESULTS

We conducted a PubMed search without filtering for publication date which resulted in 16 experimental and 22 clinical studies eligible for inclusion. Remarkably, none of the experimental and only three of the clinical studies specifically mentioned MGO-derived AGEs. Almost all studies reported an association between arterial stiffness and AGE accumulation in the arterial wall or increased plasma AGEs. Other studies report reduced arterial stiffness in experimental models upon administration of AGE-breakers.

CONCLUSIONS

No papers published to date directly show an association between MGO or MGO-derived AGEs and arterial stiffening. The relevance of the various underlying mechanisms is not yet clear, which is particularly due to methodological challenges in the detection of MGO and MGO-derived AGEs at the molecular, intra- and pericellular, and structural levels, as well as in challenges in the assessment of intrinsic arterial wall properties at ECM- and tissue levels.

Dietary inflammatory index and cardiorenal function in women with diabetes and prediabetes

BACKGROUND AND AIMS

Previous studies had shed a new light on the importance of multiple inflammatory mechanisms in the pathogenesis of arterial stiffness. The dietary inflammatory index (DII®) is a new tool for estimating the overall inflammatory potential of the diet. The aim of this study is to assess the association of the inflammatory potential of diet with peripheral arterial stiffness and renal function in women with diabetes and prediabetes.

METHODS AND RESULTS

This is an observational cross-sectional study. A total of 2644 females aged 45-75 years were included for the study. Dietary intake in the past 12 months was assessed by a validated China National Nutrition and Health Survey 2002 (CNHS2002) food-frequency questionnaire. Energy-adjusted DII (E-DII) scores were calculated from daily dietary information. In a multivariable linear regression analysis adjusted for potential confounders, E-DII was positively associated with brachial ankle pulse wave velocity (baPWV) in participants with diabetes (β = 12.820; 95% CI = 2.565, 23.076; P = 0.014) and prediabetes (β = 29.025; 95% CI = 1.110, 56.940; P = 0.042), but not in females with normal glucose homeostasis. In addition, per unit increase of E-DII was significantly associated with lower eGFR (β = -1.363; 95% CI = -2.335, -0.392; P = 0.006) in patients with diabetes.

CONCLUSION

We identified a direct association between E-DII and arterial stiffness, decreasedeGFR in middle-aged and elderly women with diabetes or prediabetes. Future studies are needed to verify and clarify the role of E-DII as an intervention target for cardiorenal complications of chronic hyperglycemia.

Effect of dietary advanced glycation end-products restriction on type 2 diabetes mellitus control: a systematic review

CONTEXT

Reducing dietary advanced glycation end-products (AGEs) may favor diabetes control.

OBJECTIVE

Critically analyze studies about the effect of dietary AGEs restriction on inflammation, oxidative stress, and glycemic control in patients with type 2 diabetes mellitus (DM2).

DATA SOURCE

This systematic review was conducted according to PRISMA methodology. The PubMed, Web of Science, LILACS, and Cochrane Library databases were searched, using the terms "type 2 diabetes," "advanced glycation end products" and "diet."

DATA EXTRACTION

Seven original studies were included in this review. The duration of the studies ranged from 1 day to 16 weeks. All extracted data were compiled, compared, and critically analyzed.

DATA ANALYSIS

Glycemic variables were considered the primary outcomes. The secondary outcomes were glycation, inflammatory, and oxidative stress markers.

CONCLUSION

Although serum insulin, homeostasis model assessment of insulin resistance, and glycated hemoglobin values were lower after the consumption of AGEs restricted diets in most studies, there was a lack of unanimity regarding dietary AGEs' positive effect on inflammation, oxidative stress, and blood glucose.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020152640.

Habitual Intake of Dietary Advanced Glycation End Products Is Not Associated with Arterial Stiffness of the Aorta and Carotid Artery in Adults: The Maastricht Study

BACKGROUND

Advanced glycation end products (AGEs), a heterogeneous group of bioactive compounds, are thought to contribute to arterial stiffness, which in turn is a causal factor in the pathogenesis of stroke, myocardial infarction, and heart failure. Whether AGEs derived from food also contribute to arterial stiffness is not clear.

OBJECTIVES

We investigated whether higher intake of dietary AGEs is associated with arterial stiffness.

METHODS

In this cross-sectional observational study in 2255 participants of The Maastricht Study (mean ± SD age: 60 ± 8 y, 51% male, mean ± SD BMI: 26.9 ± 4.4 kg/m2, n = 1326 normal glucose metabolism, n = 341 prediabetes, and n = 585 type 2 diabetes mellitus), we estimated intake of the dietary AGEs Nε-(carboxymethyl)lysine (CML), Nε-(1-carboxyethyl)lysine (CEL), and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) by a validated FFQ coupled to our ultra-performance liquid chromatography tandem mass spectrometry dietary AGE database. Arterial stiffness was determined using carotid-femoral pulse wave velocity (cfPWV), carotid distensibility coefficient (DC), and carotid Young's elastic modulus (YEM). We performed multiple linear regression analyses adjusting for potential confounders (demographic, hemodynamic, cardiovascular, and dietary factors).

RESULTS

In the fully adjusted models we observed no statistically significant associations between intake of the dietary AGEs CML, CEL, and MG-H1 and arterial stiffness expressed as cfPWV, carotid DC, and carotid YEM.

CONCLUSIONS

In adults aged 40-75 y, habitual intake of the dietary AGEs CML, CEL, and MG-H1 is not associated with arterial stiffness measured as cfPWV, carotid DC, or carotid YEM.

Role of dietary modifications in the management of type 2 diabetic complications

Diabetes is a chronic metabolic disorder with a high rate of morbidity and mortality. Insufficient insulin secretion and insulin action are two major causes for the development of diabetes, which is characterized by a persistent increase in blood glucose level. Diet and sedentary life style play pivotal role in development of vascular complications in type 2 diabetes. Dietary modification is associated with a reprogramming of nutrient intake, which are proven to be effective for the management of diabetes and associated complications. Dietary modifications modulate various molecular key players linked with the functions of nutrient signalling, regulation of autophagy, and energy metabolism. It activates silent mating type information regulation 2 homolog1 (SIRT1) and AMP-activated protein kinase (AMPK). AMPK mainly acts as an energy sensor and inhibits autophagy repressor Mammalian target of rapamycin (mTOR) under nutritional deprivation. Under calorie restriction (CR), SIRT1 gets activated directly or indirectly and plays a central role in autophagy via the regulation of protein acetylation. Dietary modification is also effective in controlling inflammation and apoptosis by decreasing the level of pro-inflammatory cytokines like nuclear factor kappa- beta (NF-kβ), tissue growth factor-beta (TGF-β), tissue necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). It also improves glucose homeostasis and insulin secretion through beta cell regeneration. This indicates calorie intake plays a crucial role in the pathogenesis of type 2 diabetes-associated complications. The present review, emphasizes the role of dietary modifications in diabetes and associated complications.

High TG to HDL ratio plays a significant role on atherosclerosis extension in prediabetes and newly diagnosed type 2 diabetes subjects

AIMS

We investigated the role of TG to HDL ratio (TG/HDL) on atherosclerosis extension, defined as presence of coronary artery calcium (CAC), carotid and femoral plaque, in prediabetes or newly diagnosed type 2 diabetes (T2D).

METHODS

We performed a retrospective, cross-sectional, single centre study involving 440 prediabetes or newly diagnosed controlled T2D subjects. Participants underwent CAC analysis by computed tomography and carotid and femoral plaque evaluation by ultrasonography and were stratified in high TG/HDL (H-TG/HDL) or low TG/HDL (L-TG/HDL) group according to TG/HDL median value. We estimated atherosclerosis extension according to the number of involved vascular districts.

RESULTS

CAC was higher in the H-TG/HDL group than L-TG/HDL group (29.15 [0.0-95.68] vs 0.0 [0.0-53.97] AU, P < .01) and CAC > 0 was more prevalent in the H-TG/HDL group than L-TG/HDL group (64.5% vs 45%, P < .001). Femoral atherosclerosis was higher in the H-TG/HDL group than L-TG/HDL group (57.3% vs 43.6%, P < .01). H-TG/HDL group exhibited a lower prevalence of subjects with 0-TWP compared to L-TG/HDL group (21.8% vs 38.6%, P < .01) and higher percentages of subjects with 2-TWP or 3-TWP than L-TG/HDL group (for 2-TWP 29.5% vs 21.5%, P < .05; for 3-TWP 32.7% vs 20.9%, P < .01). Multiple logistic regression analysis showed that a H-TG/HDL was inversely associated to 0-TWP (P < .05) and positively associated with 2-TWP (P < .05) and 3-TWP (P < .01).

CONCLUSIONS

Our data suggest that TG/HDL is a marker of increased atherosclerotic extension in prediabetes and newly diagnosed T2D and may be useful to identify subjects with a higher cardiovascular risk profile.

The association between dietary and skin advanced glycation end products: the Rotterdam Study

BACKGROUND

Advanced glycation end products (AGEs) accumulate in tissues with age and in conditions such as diabetes mellitus and chronic kidney disease (CKD), and they may be involved in age-related diseases. Skin AGEs measured as skin autofluorescence (SAF) are a noninvasive reflection of long-term AGE accumulation in tissues. Whether AGEs present in the diet (dAGEs) contribute to tissue AGEs is unclear.

OBJECTIVES

Our aim was to investigate the association between dietary and skin AGEs in the Rotterdam Study, a population-based cohort of mainly European ancestry.

METHODS

In 2515 participants, intake of 3 dAGEs [carboxymethyl-lysine (CML), N-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MGH1), and carboxyethyl-lysine (CEL)] was estimated using FFQs and the content of AGEs measured in commonly consumed foods. SAF was measured 5 y (median value) later using an AGE Reader. The association of dAGEs with SAF was analyzed in linear regression models and stratified for diabetes and chronic kidney disease (CKD, defined as estimated glomerular filtration rate ≤60 mL/min) status.

RESULTS

Mean ± SD intake was 3.40 ±0.89 mg/d for CML, 28.98 ±7.87 mg/d for MGH1, and 3.11 ±0.89 mg/d for CEL. None of them was associated with SAF in the total study population. However, in stratified analyses, CML was positively associated with SAF after excluding both individuals with diabetes and individuals with CKD: 1 SD higher daily CML intake was associated with a 0.03 (95% CI: 0.009, 0.05) arbitrary units higher SAF. MGH1 and CEL intake were not significantly associated with SAF. Nevertheless, the associations were stronger when the time difference between dAGEs and SAF measurements was shorter.

CONCLUSIONS

Higher dietary CML intake was associated with higher SAF only among participants with neither diabetes nor CKD, which may be explained by high AGE formation in diabetes and decreased excretion in CKD or by dietary modifications in these disease groups. The dAGE-SAF associations were also modified by the time difference between measurements. Our results suggest that dAGEs can influence tissue AGE accumulation and possibly thereby age-related diseases. This trial was registered at the Netherlands National Trial Register as NTR6831 (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6831) and at the WHO International Clinical Trials Registry Platform as NTR6831 (http://www.who.int/ictrp/network/primary/en/).

Binding of CML-Modified as Well as Heat-Glycated β-lactoglobulin to Receptors for AGEs Is Determined by Charge and Hydrophobicity

Intake of dietary advanced glycation end products (AGEs) is associated with inflammation-related health problems. Nε-carboxymethyl lysine (CML) is one of the best characterised AGEs in processed food. AGEs have been described as ligands for receptors present on antigen presenting cells. However, changes in protein secondary and tertiary structure also induce binding to AGE receptors. We aimed to discriminate the role of different protein modifications in binding to AGE receptors. Therefore, β-lactoglobulin was chemically modified with glyoxylic acid to produce CML and compared to β-lactoglobulin glycated with lactose. Secondary structure was monitored with circular dichroism, while hydrophobicity and formation of β-sheet structures was measured with ANS-assay and ThT-assay, respectively. Aggregation was monitored using native-PAGE. Binding to sRAGE, CD36, and galectin-3 was measured using inhibition ELISA. Even though no changes in secondary structure were observed in all tested samples, binding to AGE receptors increased with CML concentration of CML-modified β-lactoglobulin. The negative charge of CML was a crucial determinant for the binding of protein bound CML, while binding of glycated BLG was determined by increasing hydrophobicity. This shows that sRAGE, galectin-3, and CD36 bind to protein bound CML and points out the role of negatively charged AGEs in binding to AGE receptors.

Accumulation of advanced glycation end products (AGEs) is associated with the severity of aortic stenosis in patients with concomitant type 2 diabetes

BACKGROUND

Accumulation of advanced glycation end products (AGEs) leads to chronic glycation of proteins and tissue damage, particularly in patients with diabetes mellitus (DM). We aimed to evaluate whether increased accumulation of AGEs in patients with aortic stenosis (AS) and concomitant type 2 diabetes (DM) is associated with AS severity.

METHODS

We prospectively enrolled 76 patients with severe AS (47.1% males; nonDM), aged 68 [66-72] years, and 50 age-matched DM patients with a median blood glucose level of 7.5 [5.9-9.1] mM and glycated hemoglobin (HbA1c) of 6.8 [6.3-7.8]%, scheduled for aortic valve replacement. Valvular expression of AGEs, AGEs receptor (RAGE), interleukin-6 (IL-6), and reactive oxygen species (ROS) induction were evaluated ex vivo by immunostaining and calculated as the extent of positive immunoreactive areas/total sample area. Plasma levels of AGEs and soluble RAGE (sRAGE) were assessed by ELISAs.

RESULTS

Subjects with DM had increased valvular expression of both AGEs (6.6-fold higher, 15.53 [9.96-23.28]%) and RAGE (1.8-fold higher, 6.8 [4.9-8.45]%) compared to nonDM patients (2.05 [1.21-2.58]% and 2.4 [1.56-3.02]%, respectively; both p < 0.001). Plasma levels of AGEs (12-fold higher) and sRAGE (1.3-fold higher) were elevated in DM patients, compared to nonDM (both p < 0.0001). The percentage of valvular ROS-positive (2.28 [1.6-3.09] vs. 1.15 [0.94-1.4]%, p < 0.0001) but not IL-6-positive areas was higher within DM, compared to nonDM valves. In DM patients, the percentage of valvular AGEs- and RAGE-positive areas correlated with HbA1c (r = 0.77, p < 0.0001 and r = 0.30, p = 0.034). Similarly, plasma AGEs and sRAGE levels were associated with HbA1c in the DM group (r = 0.32, p = 0.024 and r = 0.33, p = 0.014, respectively). In all DM patients, we found an association between the amount of valvular AGEs and the disease severity measured as aortic valve area (AVA; r = 0.68, p < 0.0001). Additionally, in DM patients with HbA1c > 7% (n = 24, 48%) we found that valvular expression of AGEs correlated with mean transvalvular pressure gradient (PG_mean; r = 0.45, p = 0.027). Plasma AGEs levels in the whole DM group correlated with AVA (r = - 0.32, p = 0.02), PG_mean (r = 0.31, p = 0.023), and PG_max (r = 0.30, p = 0.03).

CONCLUSIONS

Our study suggests that poorly-controlled diabetes leads to increased AGEs and RAGE valvular accumulation, which at least partially, might result in AS progression in DM patients.

Differential Effects of Dietary Patterns on Advanced Glycation end Products: A Randomized Crossover Study

Dietary advanced glycation end products (AGEs) are believed to contribute to pathogenesis of diabetes and cardiovascular disease. The objective of this study was to determine if a diet high in red and processed meat and refined grains (HMD) would elevate plasma concentrations of protein-bound AGEs compared with an energy-matched diet high in whole grain, dairy, nuts and legumes (HWD). We conducted a randomized crossover trial with two 4-week weight-stable dietary interventions in 51 participants without type 2 diabetes (15 men and 36 women aged 35.1 ± 15.6 y; body mass index (BMI), 27.7 ± 6.9 kg/m²). Plasma concentrations of protein-bound Nε-(carboxymethyl) lysine (CML), Nε-(1-carboxyethyl) lysine (CEL) and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were measured by liquid chromatography–tandem mass spectrometry (LC-MS/MS). The HMD significantly increased plasma concentrations (nmol/mL) of CEL (1.367, 0.78 vs. 1.096, 0.65; p < 0.01; n = 48) compared with the HWD. No differences in CML and MG-H1 between HMD and HWD were observed. HMD increased plasma CEL concentrations compared with HWD in individuals without type 2 diabetes.

Putative functional non-coding polymorphisms in SELP significantly modulate sP-selectin levels, arterial stiffness and type 2 diabetes mellitus susceptibility

BACKGROUND

P-selectin, encoded by SELP, has been implicated as an important molecule in the development of arterial stiffness, consequently leading to vascular complications in T2DM. SELP polymorphisms and increased levels of soluble P-selectin (sP-selectin) have been shown to be associated with several inflammatory diseases. The present work was designed to assess nine putative functional non-coding SELP variants in relation to sP-selectin levels and arterial stiffness in T2DM.

METHODS

The genetic distribution of rs3917655, rs3917657, rs3917739, rs2235302, rs3917843 was determined by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). Genotyping of rs3917779 was performed by tetra primer amplification-refractory mutation system (ARMS)- PCR. Three SNPs i.e. rs3917853, rs3917854, rs3917855 were genotyped by Sanger sequencing. Construction of haplotypes was performed using PHASE software. The data thus obtained was analyzed by appropriate statistical tools.

RESULTS

Two non-coding variants i.e. rs3917657 and rs3917854 of SELP were found to be associated with 2 and 1.7 -fold risk of disease development respectively. However, one non-coding variant rs2235302 was found to provide protection against disease development. Furthermore, variant allele of rs3917854 in T2DM patients was found to be associated with 2.07-fold very high vascular risk. Non-coding haplotype GCAGGCCGC was conferring 4.14-fold risk of disease development. Furthermore, overall sP-selectin levels were higher in T2DM patients when segregated according to genotypes as well as haplotypes. Significant genotype- phenotype correlation was observed for rs3917655 as well as rs3917739 variant in patients and for rs3917854 in controls. In vascular risk categories, a significant genotype- phenotype correlation was observed for rs3917655 and rs2235302. Furthermore, patients with CCGGGCCGC haplotype in high risk category were observed with higher levels of sP-selectin as compared to other haplotypes (p < 0.05).

CONCLUSIONS

Non-coding SELP variants may significantly modulate sP-selectin levels, vascular risk and T2DM susceptibility.

Relation of Helicobacter pylori infection to peripheral arterial stiffness and 10-year cardiovascular risk in subjects with diabetes mellitus

PURPOSE

This study was conducted to investigate the relation of HP infection to peripheral arterial stiffness and 10-year cardiovascular risk in diabetes mellitus (DM).

METHODS

DM subjects who underwent the C13-breath test were enrolled and divided into DMHP+ and DMHP- groups. Peripheral arterial stiffness was measured using brachial to ankle pulse wave velocity (baPWV). Framingham score (FRS) and Chinese evaluation method of ischemic cardiovascular diseases (ICVD) were used to clarify 10-year cardiovascular risk.

RESULTS

A total of 6767 subjects were included, baPWV and proportion of subjects with severe peripheral arterial stiffness were lower in DMHP- group than DMHP+ group (1556.68 ± 227.54 vs 2031.61 ± 525.48 cm/s, p < 0.01; 21.9% vs 62.7%, p < 0.01). Multivariate logistic regression analysis demonstrated that HP infection was independently associated with baPWV. Furthermore, cardiovascular risk score and the proportion of subjects with high risk were lower in DMHP- group than DMHP+ group (FRS: 12.09 ± 3.77 vs 13.91 ± 3.77, 17.2% vs 38.8%; ICVD: 8.56 ± 2.99 vs 10.22 ± 3.16, 43.9% vs 65.4%, with all p < 0.05).

CONCLUSION

DM subjects with HP infection had more severe peripheral arterial stiffness compared those without HP infection, a higher cardiovascular risk score and 10-year cardiovascular risk stratification were observed in those subjects.

Total White Blood Cell Count Mediated the Association Between Increased Arterial Stiffness and Risk of Type 2 Diabetes Mellitus in Chinese Adults

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is known to be related to increased arterial stiffness. However, little is known about the risk of T2DM due to accelerated arterial stiffness and the underlying mechanism involved. We aimed to examine arterial stiffness, as determined by brachial-ankle pulse wave velocity (baPWV), in relation to T2DM among a community-based population and whether the association was mediated by white blood cell (WBC) counts. Approach and results: A total of 1036 Chinese adults aged 64.3 years with complete data were qualified in the present study. The dose-response association between baPWV levels, WBC counts, and risk of T2DM were explored using generalized linear models or multivariate logistic regression models. A mediation analysis was conducted to investigate the role of WBC counts on the association between baPWV and T2DM. After multivariate adjustments, we observed a dose-responsive relationship between increased baPWV and elevated risk of T2DM: comparing extreme tertiles of baPWV, the adjusted odds ratio for T2DM risk was 2.29 (95% CI, 1.32-3.98; P for trend =0.005). In addition, significant dose-dependent relationships were found across baPWV tertiles with increasing total or differential WBC counts, which in turn, were positively related to higher risk of T2DM (all P for trend <0.05). Mediation analyses indicated that total WBC count mediated 4.5% of the association between increased baPWV and elevated T2DM risk.

CONCLUSIONS

Increased arterial stiffness might increase T2DM risk among middle-aged and older Chinese adults, which was partially mediated by total WBC count.

Analysis of HDL-microRNA panel in heterozygous familial hypercholesterolemia subjects with LDL receptor null or defective mutation

In the last years increasing attention has been given to the connection between genotype/phenotype and cardiovascular events in subjects with familial hypercholesterolemia (FH). MicroRNAs (miRs) bound to high-density lipoprotein (HDL) may contribute to better discriminate the cardiovascular risk of FH subjects. Our aim was to evaluate the HDL-miR panel in heterozygous FH (HeFH) patients with an LDLR null or defective mutation and its association with pulse wave velocity (PWV). We evaluated lipid panel, HDL-miR panel and PWV in 32 LDLR null mutation (LDLR-null group) and 35 LDLR defective variant (LDLR-defective group) HeFH patients. HDL-miR-486 and HDL-miR-92a levels were more expressed in the LDLR-null group than the LDLR-defective group. When we further stratified the study population into three groups according to both the LDLR genotype and history of ASCVD (LDLR-null/not-ASCVD, LDLR-defective/not-ASCVD and LDLR/ASCVD groups), both the LDLR/ASCVD and the LDLR-null/not-ASCVD groups had a higher expression of HDL-miR-486 and HDL-miR-92a than the LDLR-defective/not-ASCVD group. Finally, HDL-miR-486 and HDL-miR-92a were independently associated with PWV. In conclusion, the LDLR-null group exhibited HDL-miR-486 and HDL-miR-92a levels more expressed than the LDLR-defective group. Further studies are needed to evaluate these HDL-miRs as predictive biomarkers of cardiovascular events in FH.

Potential effect of advanced glycation end products (AGEs) on spermatogenesis and sperm quality in rodents

The aim of the present study was to assess whether dietary advanced glycation end products (AGEs) induce testicular dysfunction. Using a BALB/c mouse model, AGE intake and serum levels were found to increase in AGE diet-treated mice relative to the controls. Histopathological damage was detected in the testes and epididymides of the AGE diet-induced mice. The total number of epididymal sperm decreased, and increased abnormal sperm rate was found in the mice. Moreover, the mice testes showed an increased level of the receptor for AGEs (RAGE) and malondialdehyde (MDA). Using a Sprague-Dawley rat model, AGE diet-induced rats showed 3- to 4-fold higher AGE intake than the controls. In these rats, higher serum and sperm MDA levels, decreased epididymal sperm numbers, and increased abnormal sperm rates were also observed. Silymarin, a natural AGE inhibitor, was found to restore these AGE-induced phenomena. Concluding from the above findings, dietary AGEs may promote testicular dysfunction.