Accumulation of advanced glycation end products evaluated by skin autofluorescence and incident frailty in older adults from the Bordeaux Three-City cohort

Advanced Glycation End-Products and Metabolomics Are Independently Associated With Frailty: The Longitudinal Doetinchem Cohort Study

Skin autofluorescence (SAF), reflecting advanced glycation endproducts' accumulation in tissue, has been proposed as a noninvasive aging biomarker. Yet, SAF has not been compared with well-established blood-based aging biomarkers such as MetaboHealth in association with frailty. Furthermore, no previous study determined the longitudinal association of SAF with frailty. We used 2 382 Doetinchem Cohort Study participants' (aged 46.0-85.4) cross-sectional data, of whom 1 654 had longitudinal SAF measurements. SAF was measured using the AGE Reader. MetaboHealth was calculated on 1H-NMR-metabolomics. Linear regressions were used for the associations of SAF and MetaboHealth on the 36-deficit frailty index and logistic regressions for being pre-frail or frail as determined by the frailty phenotype. Longitudinal associations were determined by an interaction term between age and SAF in a linear mixed model. SAF and MetaboHealth were associated with higher odds of pre-frailty (odd ratios per standard deviation SAF: 1.21 [1.10-1.32], MetaboHealth: 1.35 [1.24-1.49]) and frailty (SAF: 1.70 [1.41-2.06], MetaboHealth: 1.90 [1.57-2.32]). When mutually adjusted, both aging biomarkers remained associated with pre-frailty (SAF: 1.16 [1.05-1.27], MetaboHealth 1.33 [1.21-1.46]) and frailty (SAF: 1.52 [1.25-1.85], MetaboHealth: 1.75 [1.43-2.14]). Additionally, SAF and MetaboHealth were associated with higher frailty index scores (percentage increase per standard deviation SAF: 1.35 [1.00-1.70], MetaboHealth: 1.87 [1.54-2.20]), also after mutual adjustment (SAF: 1.02 [0.68-1.37], MetaboHealth: 1.69 [1.35-2.02]). SAF was also longitudinally associated with the frailty index (percentage per unit/year increase: 0.12 [0.07-0.16]). The mutual independence of SAF and MetaboHealth implies they capture distinct aspects of the aging process. Altogether, these findings emphasize SAF's clinical potential as an age-related decline biomarker, which could be further enhanced when combined with MetaboHealth.

Association between advanced glycation end-products and fall risk in older adults: The Yakumo Study

AIM

Advanced glycation end-products (AGEs) are irreversibly and heterogeneously formed compounds during the non-enzymatic modification of macromolecules, such as proteins. Aging and lifestyle habits, such as high-fat and high-protein diets, and smoking, promote AGEs accumulation. This study aimed to investigate the relationship between fall risk and AGEs in community-dwelling older adults.

METHODS

This cross-sectional study included patients from the 2022 Yakumo Study who were evaluated for fall risk index 5-items version, locomotive syndrome stage and AGEs. AGEs were evaluated using Skin autofluorescence (SAF) measured by the AGE reader (DiagnOptics Technologies BV, Groningen, the Netherlands). We divided the participants into two groups according to the presence or absence of fall risk (fall risk index 5-items version ≥6 or not), and investigated the factors associated with fall risk.

RESULTS

The fall risk group had a higher age and SAF, and a higher proportion of locomotive syndrome stage >2 than the without fall risk group in patients aged ≥65 years (P < 0.01). The multivariate logistic regression analysis after adjustment of age, sex and body mass index showed that locomotive syndrome stage ≥2 and SAF were independent associators of fall risk in older adults (odds ratio 3.26, P < 0.01, odds ratio 2.96, P < 0.05, respectively). The optimal cutoff value of the SAF for fall risk was 2.4 (area under the curve 0.631; 95% CI 0.53-0.733; sensitivity 0.415; specificity 0.814; P < 0.05).

CONCLUSION

The accumulation of AGEs in skin tissues can be used to screen for fall risk comprehensively. Geriatr Gerontol Int 2024; 24: 517-522.

Association of Autofluorescent Advanced Glycation End Products (AGEs) with Frailty Components in Chronic Kidney Disease (CKD): Data from a Single-Center Cohort Study

BACKGROUND

Chronic kidney disease (CKD) is characterized by an overproduction and accumulation of advanced glycation end products (AGEs). Because AGEs may play a role in the development of malnutrition and sarcopenia, two essential components of frailty, we evaluated whether they may also contribute to the onset of frailty in CKD patients.

METHODS

We performed a cross-sectional analysis of 117 patients. AGEs were quantified using a fluorescence spectrophotometer and soluble receptor for AGE (sRAGE) isoforms by ELISA. We defined frailty according to the frailty phenotype (FP) proposed by Fried.

RESULTS

The average age of patients was 80 ± 11 years, 70% were male, and the mean eGFR was 25 + 11 mL/min/1.73m². Frailty was diagnosed in 51 patients, and 40 patients were classified as pre-frail. AGEs and RAGE isoforms seem not to correlate with overall frailty. Instead, AGEs were associated with specific frailty domains, inversely associated with BMI (R = -0.22, p = 0.016) and directly associated with gait test time (R = 0.17, p = 0.049). AGEs were also associated with involuntary weight loss (OR 1.84 p = 0.027), independent of age and sex.

CONCLUSIONS

AGEs are associated with some pivotal components of the frailty phenotype, although they are not associated with frailty overall.

Dietary advanced glycation end-products (dAGEs) intake and its relation to sarcopenia and frailty - The Rotterdam Study

Studies on mice have shown a relationship between dietary intake of advanced glycation end-products (dAGEs) and deterioration of musculoskeletal health, but human studies are absent. We investigated the relationship between dietary intake of carboxymethyllysine (dCML) - an AGE prototype - and risk of sarcopenia at baseline and after 5 years of follow-up and a single evaluation of physical frailty in participants from the population-based Rotterdam Study. Appendicular lean mass (ALM) was obtained using insight dual-energy X-ray absorptiometry and hand grip strength (HGS) using a hydraulic hand dynamometer. Subjects with both low ALM and weak HGS were classified as having sarcopenia. Frailty (yes/no) was defined by presence of ≥3 and pre-frailty by presence of 1 or 2 components namely, exhaustion, weakness, slowness, weight loss or low physical activity. dCML was calculated using a food frequency questionnaire and dAGE databases. Logistic regression analysis was used to evaluate the odds of physical frailty and prevalent sarcopenia at baseline and follow-up and incident sarcopenia. 2782 participants with an age 66.4 ± 9.9 years and dCML intake 3.3 ± 1.3 mg/day, had data on sarcopenia at both time points. Of whom 84 had sarcopenia at baseline and 73 developed sarcopenia at follow-up. We observed an association of one SD increase in dCML intake with prevalent sarcopenia at baseline [odds ratio, OR = 1.27 (1.01-1.59)] and no association of dCML with incident sarcopenia at 5-year follow-up [OR = 1.12 (0.86-1.44)]. For frailty we analyzed 3577 participants, of whom 1972 were pre-frail and 158 were frail. We observed no association of dCML with either pre-frailty [OR = 0.99 (0.91-1.07)] or frailty [OR = 1.01 (0.83-1.22)] when non-frail subjects were used as reference. Our results show an association of dAGEs with sarcopenia cross-sectionally but not longitudinally where inconclusive findings are observed possibly due to a very low incidence of sarcopenia. There was no association with frailty cross-sectionally.

Skin Autofluorescence Measurement as Initial Assessment of Hepatic Parenchyma Quality in Patients Undergoing Liver Resection

Skin autofluorescence (SAF) can detect advanced glycation end products (AGEs) that accumulate in tissues over time. AGEs reflect patients’ general health, and their pathological accumulation has been associated with various diseases. This study aimed to determine whether its measurements can correlate with the liver parenchyma quality. This prospective study included 186 patients who underwent liver resections. Liver fibrosis and/or steatosis > 10% were found in almost 30% of the patients. ROC analysis for SAF revealed the optimal cutoff point of 2.4 AU as an independent predictor for macrovesicular steatosis ≥ 10% with an AUC of 0.629 (95% CI 0.538−0.721, p = 0.006), 59.9% sensitivity, 62.4% specificity, and positive (PPV) and negative (NPV) predictive values of 45.7% and 74.1%, respectively. The optimal cutoff point for liver fibrosis was 2.3 AU with an AUC of 0.613 (95% CI 0.519−0.708, p = 0.018), 67.3% sensitivity, 55.2% specificity, and PPV and NPV of 37.1% and 81.2%, respectively. In the multivariable logistic regression model, SAF ≥ 2.4 AU (OR 2.16; 95% CI 1.05−4.43; p = 0.036) and BMI (OR 1.21; 95% CI 1.10−1.33, p < 0.001) were independent predictors of macrovesicular steatosis ≥ 10%. SAF may enhance the available non-invasive methods of detecting hepatic steatosis and fibrosis in patients prior to liver resection.

Skin autofluorescence, a non-invasive biomarker of advanced glycation end-products (AGEs), is associated with frailty: The Rotterdam study

Background

Accumulation of advanced glycation end-products (AGEs) in tissues has been linked to various age-related disease phenotypes. Therefore, we investigated the potential relationship between skin AGE accumulation and frailty.

Methods

A cross-sectional analysis was performed on 2 521 participants from the Rotterdam Study. Skin AGEs were assessed as skin autofluorescence (SAF) using the AGE reader™. We used 2 approaches to define frailty. Fried’s criteria, including weight loss, weakness, slow gait speed, exhaustion, and low physical activity, were used to define physical frailty (presence of ≥3 components) and prefrailty (presence of ≤2 components). Rockwood’s concept, including 38 deficits from physical and psychosocial health domains, was used to calculate the frailty index (score 0–1). Multinomial logistic and multivariate linear regression were used with SAF as exposure and physical frailty (ordinal) and frailty index (continuous) as outcome adjusting for age, sex, diabetes, renal function, socioeconomic status, and smoking status.

Results

The mean SAF was 2.39 ± 0.49 arbitrary units and the median age was 74.2 (14.0) years. Regarding physical frailty, 96 persons (4%) were frail and 1 221 (48%) were prefrail. Skin autofluorescence was associated with both being prefrail (odds ratio [95% confidence interval] = 1.29 [1.07–1.56]) and frail (1.87 [1.20–2.90]) compared with nonfrail. Regarding the frailty index, the median value was 0.14 (0.10–0.19) and higher SAF was also associated with a higher frailty index (coefficient, B = 0.017 (0.011–0.023]).

Conclusions

Higher skin AGEs are associated with both physical frailty and frailty index. Longitudinal studies are needed to evaluate the causality and the potential of SAF as a biomarker to screen frailty.

Effect of a Topical Collagen Tripeptide on Antiaging and Inhibition of Glycation of the Skin: A Pilot Study

The glycation process has been recognized as one of the critical parameters that accelerate signs of skin aging, especially in skin exposed to environment factors, such as ultraviolet radiation. Although previous studies showed the anti-inflammatory and antiaging properties of the hydrolyzed collagen tripeptide (CTP), its exact mechanism is not fully understood. Therefore, in this study, we sought to investigate the effect of a topical CTP on facial skin. Our group designed a 4 week prospective, single-arm study of 22 Asian women who applied topical CTP. We observed significant improvements in skin wrinkles, elasticity, and density with a reduction in skin accumulation of advanced glycated end products (AGEs) at week 4 without any adverse effects. The in vitro study revealed a preventive effect of the topical CTP on the accumulation of AGEs, denatured collagen production, and reactive oxygen species in dermal fibroblasts. Moreover, treatment with the CTP decreased induction of matrix metalloproteinases while increasing the collagen 1 level. These results suggest that the application of a topical CTP might improve clinical aging phenotypes via the inhibition of glycation and oxidative stress, leading to a delay in cellular aging.

Relevance of oxidative stress and inflammation in frailty based on human studies and mouse models

Frailty represents a state of vulnerability and increases the risk of negative health outcomes, which is becoming an important public health problem. Over recent years, multiple independent studies have attempted to identify biomarkers that can predict, diagnose, and monitor frailty at the biological level. Among them, several promising candidates have been associated with frailty status including antioxidants and free radicals, and also inflammatory response biomarkers. In this review, we will summarize the more recent advances in this field. Moreover, the identification of scales and measurements to detect and quantify frailty in aged mice, as well as the generation of mouse models, have started to unravel the underlying biological and molecular mechanisms of frailty. We will discuss them here with an emphasis on murine models with overexpression of glucose-6-phosphate dehydrogenase and loss of function of superoxide dismutase and interleukin 10, which reveal that altered oxidative stress and inflammation pathways are involved in the physiopathology of frailty. In summary, we provide the current available evidence, from both human cohorts and experimental animal models, that highlights oxidative damage and inflammation as relevant biomarkers and drivers of frailty.

Relationship among urinary advanced glycation-end products, skeletal muscle mass and physical performance in community-dwelling older adults

AIM

Advanced glycation end-products are important factors in muscle function and physical performance among older adults. However, the association between sarcopenia and urinary carboxymethyl-lysine (uCML) levels remains unclear. The present study aimed to investigate the relationship among uCML levels, skeletal muscle mass, physical performance and sarcopenia among community-dwelling older adults.

METHODS

This work was a community-based cross-sectional study. The participants were recruited from the Taichung Community Health Study-Elderly and were followed up until 2017. A total of 104 participants underwent dual-energy X-ray absorptiometry examination, physical performance tests and measurement of uCML levels. After the natural log transformation of the uCML levels, Pearson's correlation coefficient and a general linear model were used for statistical analysis.

RESULTS

The mean uCML levels of older men and women were 1.34 μg/mg and 1.63 μg/mg creatinine, respectively. After multivariate adjustment, grip strength among older women significantly decreased as uCML levels increased. Participants with uCML levels and Timed Up and Go test values higher than the median had a 13.76-fold risk of acquiring sarcopenia compared with those whose corresponding variables were lower than the median after adjusting for age, sex, body fat percentage, and serum creatinine and blood urea nitrogen levels.

CONCLUSIONS

uCML levels were negatively associated with grip strength among older women. The joint association of uCML and Timed Up and Go test values was correlated with the risk of acquiring sarcopenia among older adults. This finding suggests that uCML levels can be used as a biomarker for screening sarcopenia and as a strategy for treating sarcopenia. Geriatr Gerontol Int 2019; 19: 1017-1022.

Post-translational modification-derived products are associated with frailty status in elderly subjects

Background Identifying frail elderly subjects is of paramount importance in order to conduct a tailored care. The characterization of frailty status is currently based on the collection of clinical data and on the use of various tools such as Fried's criteria, which constitutes a difficult and time-consuming process. Up to now, no biological markers have been described as reliable tools for frailty characterization. We tested the hypothesis that a link between frailty and protein molecular aging existed. This study aimed therefore at determining whether post-translational modification derived products (PTMDPs), recognized as biomarkers of protein aging, were associated with frailty status in elderly subjects. Methods Frailty status was determined according to Fried's criteria in 250 elderly patients (>65 years old) hospitalized in a short-term care unit. Serum concentrations of protein-bound PTMDPs, including carboxymethyllysine (CML), pentosidine, methylglyoxal-hydroimidazolone-1 and homocitrulline (HCit), were determined by liquid chromatography coupled with tandem mass spectrometry, and tissue content of advanced glycation end-products was assessed by skin autofluorescence (SAF) measurement. Associations between PTMDPs and frailty status were analyzed using logistic regression models. Results Frail patients had significantly (p<0.01) higher CML, HCit, and SAF values compared to non-frail and pre-frail subjects. By multivariate analysis, only HCit concentrations and SAF values remained associated with frailty status (p=0.016 and p=0.002, respectively), independently of age, comorbidities, renal function, C-reactive protein and albumin concentrations. Conclusions HCit and SAF are significantly associated with frailty status in elderly subjects. This study suggests that PTMDPs constitute promising biomarkers for identifying frail patients and guiding personalized patient care.

Noninvasive assessments of skin glycated proteins by fluorescence and Raman techniques in diabetics and nondiabetics

Diabetes is a complex metabolic disease and has chronic complications. It has been considered a serious public health problem. The aim of the current study was to evaluate skin glycated proteins through fluorescence and Raman techniques. One hundred subjects were invited to participate in the study. Six volunteers did not attend due to exclusion criteria or a change of mind about participating. Therefore, 94 volunteers were grouped according to age range (20-80 years), health condition (nondiabetic, with insulin resistance [IR] and/or diabetic) and Fitzpatrick skin type (I-VI). The fluorescence spectrometer and the portable Raman spectroscopy system were used to measure glycated proteins from the skin. There was elevated skin autofluorescence in healthy middle-aged and elderly subjects, as well as in patients with IR and/or diabetes. Regarding Raman spectroscopy, changes in the skin hydration state, degradation of type I collagen and greater glycation were related for diabetes and chronological aging. Weak and positive correlation between the skin autofluorescence and the Raman peaks ratio (855/876) related to the glycated proteins was also found. Raman spectroscopy shows several bands for spectral analyses, complementing the fluorescence data. Therefore, this study contributes to understanding of the optical of human skin for noninvasive diabetes screening.

Skin autofluorescence predicts major adverse cardiovascular events in patients with type 1 diabetes: a 7-year follow-up study

Background

Advanced glycation end-products play a role in diabetic vascular complications. Their optical properties allow to estimate their accumulation in tissues by measuring the skin autofluorescence (SAF). We searched for an association between SAF and major adverse cardiovascular events (MACE) incidence in subjects with Type 1 Diabetes (T1D) during a 7 year follow-up.

Methods

During year 2009, 232 subjects with T1D were included. SAF measurement, clinical [age, sex, body mass index (BMI), comorbidities] and biological data (HbA1C, blood lipids, renal parameters) were recorded. MACE (myocardial infarction, stroke, lower extremity amputation or a revascularization procedure) were registered at visits in the center or by phone call to general practitioners until 2016.

Results

The participants were mainly men (59.5%), 51.5 ± 16.7 years old, with BMI 25.0 ± 4.1 kg/m², diabetes duration 21.5 ± 13.6 years, HbA1C 7.6 ± 1.1%. LDL cholesterol was 1.04 ± 0.29 g/L, estimated Glomerular Filtration Rates (CKD-EPI): 86.3 ± 26.6 ml/min/1.73 m². Among these subjects, 25.1% were smokers, 45.3% had arterial hypertension, 15.9% had elevated AER (≥ 30 mg/24 h), and 9.9% subjects had a history of previous MACE. From 2009 to 2016, 22 patients had at least one new MACE: 6 myocardial infarctions, 1 lower limb amputation, 15 revascularization procedures. Their SAF was 2.63 ± 0.73 arbitrary units (AU) vs 2.08 ± 0.54 for other patients (p = 0.002). Using Cox-model, after adjustment for age (as the scale time), sex, diabetes duration, BMI, hypertension, smoking status, albumin excretion rates, statin treatment and a previous history of MACE, higher baseline levels of SAF were significantly associated with an increased risk of MACE during follow-up (HR = 4.13 [1.30–13.07]; p = 0.02 for 1 AU of SAF) and Kaplan–Meier curve follow-up showed significantly more frequent MACE in group with SAF upper the median (p = 0.001).

Conclusion

A high SAF predicts MACE in patients with T1D.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0718-8) contains supplementary material, which is available to authorized users.

Oxidative stress, aging, and diseases

Reactive oxygen and nitrogen species (RONS) are produced by several endogenous and exogenous processes, and their negative effects are neutralized by antioxidant defenses. Oxidative stress occurs from the imbalance between RONS production and these antioxidant defenses. Aging is a process characterized by the progressive loss of tissue and organ function. The oxidative stress theory of aging is based on the hypothesis that age-associated functional losses are due to the accumulation of RONS-induced damages. At the same time, oxidative stress is involved in several age-related conditions (ie, cardiovascular diseases [CVDs], chronic obstructive pulmonary disease, chronic kidney disease, neurodegenerative diseases, and cancer), including sarcopenia and frailty. Different types of oxidative stress biomarkers have been identified and may provide important information about the efficacy of the treatment, guiding the selection of the most effective drugs/dose regimens for patients and, if particularly relevant from a pathophysiological point of view, acting on a specific therapeutic target. Given the important role of oxidative stress in the pathogenesis of many clinical conditions and aging, antioxidant therapy could positively affect the natural history of several diseases, but further investigation is needed to evaluate the real efficacy of these therapeutic interventions. The purpose of this paper is to provide a review of literature on this complex topic of ever increasing interest.