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IntroductionThe accumulation of tissue-advanced glycation end products in skin results from complex and consecutive reactions and can be measured by skin autofluorescence (SAF) reader devices. This overview discusses studies evaluating the utilization of SAF in screening renal and cardiac disease.Materials and methodsLiterature search was performed using Google Scholar, PubMed, Springer, Ovid, and ScienceDirect.ResultsSAF was an independent predictor of progression of chronic kidney disease (CKD) and was elevated in subjects on hemodialysis and peritoneal dialysis. Furthermore, SAF was significantly associated with cardiovascular events, cardiovascular mortality, and all-cause mortality in CKD patients. Other studies revealed a correlation between SAF and arterial stiffness, vascular damage, and subclinical atherosclerosis. A vegetarian diet was associated with lower SAF levels, whereas malnutrition was correlated with higher levels and increased mortality.ConclusionsSAF measurement may be useful in managing renal and cardiac disease. Future studies are needed to clarify the specific role of SAF in the management of CKD and its noninvasive office utilization to identify comorbidities in inflammatory diseases, such as psoriasis.

Aim To determine the relationship between bone microarchitecture, as measured by trabecular bone score, and advanced glycation end-product accumulation, as assessed by skin autofluorescence. Methods This was a cross-sectional study. Participants were 64 post-menopausal women with type 2 diabetes and 175 post-menopausal women without diabetes. Trabecular bone score and skin autofluorescence data were obtained at time of bone density measurement. Results Trabecular bone score and skin autofluorescence were inversely correlated in women with type 2 diabetes (r = -0.34, P = 0.006); no correlation was seen in post-menopausal women without diabetes (r = -0.029, P = 0.707). After adjustment, neither skin autofluorescence nor a diagnosis of diabetes were associated with trabecular bone score, but HbA1c and waist circumference were independently associated with trabecular bone score. Conclusion Skin autofluorescence did not predict trabecular bone score. In contrast, glycaemia, as reflected by HbA1c , and visceral adiposity, as reflected by waist circumference, were independently associated with trabecular bone score.

AIM To evaluate the association between skin advanced glycation end products and insulin resistance in Type 1 diabetes. METHODS The study group consisted of 476 people with Type 1 diabetes (247 men) with a median (interquartile range) age of 42 (33-53) years, disease duration of 24 (19-32) years and HbA1c concentration of 63 (55-74) mmol/mol [7.9 (7.2-8.9)%]. Insulin resistance was assessed according to estimated glucose disposal rate. Advanced glycation product accumulation in the skin was measured by autofluorescence using an AGE Reader. The group was divided into three subgroups based on estimated glucose disposal rate tertiles ( 9.5 mg/kg/min, respectively). The higher the estimated glucose disposal rate, the lower the insulin resistance. RESULTS Skin autofluoresence level decreased with increasing estimated glucose disposal rate; comparing people below the lower tertile, with those between the first and third tertiles, and with those above the third tertile, the median autofluoresences were, respectively: 2.5 (2.2-2.9) vs 2.3 (2.0-2.7) vs 2.1 (1.9-2.5) AU (P

AIM: To measure skin autofluorescence in youth (

Tissue advanced glycation end products (AGEs) are a measure of cumulative metabolic and oxidative stress and cytokine-driven inflammatory reactions. AGEs are thought to contribute to the cardiovascular complications of hemodialysis (HD) patients. Skin autofluorescence (SAF) is related to the tissue accumulation of AGEs and rises with age. SAF is one of the strongest prognostic markers of mortality in these patients. The content of AGEs is high in barbecue food. Due to the location in northern Sweden, there is a short intense barbecue season between June and August. The aim of this study was to investigate if seasonal variations in SAF exist in HD patients, especially during the barbecue season. SAF was measured noninvasively with an AGE Reader in 34 HD-patients (15 of those with diabetes mellitus, DM). Each time the median of three measures were used. Skin-AF was measured before and after each one HD at the end of February and May in 31 patients (22 men/9 women); the end of May and August in 28 (20 m/8 w); the end of August and March in 25 (19 m/6 w). Paired statistical analyses were performed during all four periods (n = 23, 17 m/6 w); as was HbA1c of those with DM. There was at a median 5.6% increase in skin-AF during the winter period (February-May, P = 0.004) and a 10.6% decrease in the skin-AF during the summer (May-August, P

HighlightsSkin autofluorescence (SAF) assesses subcutaneous accumulation of advanced glycation end products and has been shown to predict future cardiovascular disease and diabetes.A higher number of pregnancies was significantly associated with higher SAF, even after correction for relevant confounders like waist circumference, creatinine clearance, and diabetes status, but not after correction for age.Women with the highest SAF Z-score had a more unfavorable risk factor profile, with higher body mass index and waist circumference, higher blood pressure, lower high-density lipoprotein cholesterol, and higher triglyceride levels.

Background As life expectancy is increasing and healthy ageing becomes more and more important, skin ageing is a growing topic of interest from both a medical and a commercial point of view. The urgency to unravel the causes of skin ageing is rising. However, there is a lack of objective, simple, noninvasive methods to assess biological skin age - a term introduced to describe how old someone looks, covering both the appearance and function of the skin. A rapid, noninvasive assessment of biological skin age would greatly facilitate the execution of the studies required to find the causes of skin ageing.Objectives To find an objective, easy-to-apply method to assess biological skin age.Methods Skin age score (SAS) was compared with skin autofluorescence, a measure of advanced glycation end products in the skin, and several subject characteristics in 32 healthy, white women with little sun-exposed skin and no history of smoking.Results A moderate, positive correlation (R-2 = 0.32, P = 0.001) between SAS and skin autofluorescence-based biological skin age was found. However, the variation in biological skin age according to SAS could be explained better by body mass index, chronological age and hormonal status (R-2 = 0.86, P Conclusions In the current setting skin autofluorescence did not contribute better to the prediction of biological skin age than chronological age. Biological skin age was best predicted by body mass index, chronological age and hormonal status, and this approach provides a considerable simplification of the application of biological skin age.

In a paper published at the J Invest Dermatol in 1998 Nik Kollias and coworkers described distinct changes in skin native fluorescence associated with skin aging and photoaging, using in vivo fluorescence excitation spectroscopy. The assignment of the 295 nm band to tryptophan fluorescence had a profound significance influencing many later studies from multiple groups. The reproducible changes in skin native fluorescence suggested that aging causes predictable alterations in both the epidermis and the dermis, whereas chronic UV exposure induces the appearance of new fluorophores. This seminal, but insufficiently widely appreciated work deserves re-examination as it points to important horizons in future experimental dermatology, such as cancer diagnostics, diabetes, wound healing, and understanding skin aging and photoaging mechanisms.

Skin autofluorescence is increased in diabetes, rises with age, and predicts diabetes-related complications. Exposure to secondhand smoke, because one or more family members are smokers, further increases skin autofluorescence in children and young adults with type 1 diabetes. Elimination of passive smoking should be a goal in diabetes education. Association between age and skin autofluorescence (SAF), in arbitrary units (AU), in young people with type 1 diabetes exposed (black dots) and not exposed (open dots) to secondhand smoke. Regression lines show correlations between these parameters in exposed (solid line) and not exposed (dashed line) patients.

Aim To determine whether skin autofluorescence can help to detect those who have previously had abnormal glucose levels among women referred for diabetes during pregnancy. Methods Using an advanced glycation end product reader (AGE Readertm; DiagnOptics BV, Groningen, the Netherlands), we measured forearm skin autofluorescence at 24–30 weeks of gestation in all women who were referred to our Nutrition Diabetology unit for diabetes during pregnancy. Results The study included 230 women (200 with gestational diabetes and 30 with pre-gestational diabetes, of whom 21 had Type 1 and nine had Type 2 diabetes) and a reference group of 22 normoglycaemic non-pregnant women. Skin autofluorescence was significantly higher in women with pre-gestational diabetes (1.97 ± 0.44 arbitary units) compared with gestational diabetes (1.77 ± 0.32 arbitary units; P = 0.003) and lower in the reference group (1.60 ± 0.32 arbitary units; P = 0.009 vs all pregnant women). Among women with gestational diabetes, 71 had a history of hyperglycaemia (i.e. gestational diabetes or macrosomia in a previous pregnancy or discovery of diabetes before 24th gestational week in the present pregnancy). These women had higher levels of skin autofluorescence (1.83 ± 0.35 arbitary units) than women with gestational diabetes without previous history of hyperglycaemia (1.73 ± 0.30 arbitary units; P = 0.04, non-significant, adjusted for age). Skin autofluorescence increased with the number of criteria present for previous hyperglycaemia (P for trend = 0.008) and was significantly associated with having two or three criteria for hyperglycaemia after adjusting for age (P = 0.02). Conclusions Skin autofluorescence could reflect previous long-term hyperglycaemia in pregnant women, and could therefore be a marker of metabolic memory.

Background: Advanced glycation end-products are a heterogeneous group of molecules that are formed during reactions between reducing sugars and proteins. Advanced glycation end-products are thought to play a role in several diseases, including diabetes mellitus and can be measured non-invasively using skin autofluorescence (AF). The aim of this cross-sectional study was to investigate associations between skin AF and cardio-metabolic, lifestyle, and dietary factors within a general population.Methods: The NQplus study is an ongoing longitudinal study in the surroundings of Wageningen, the Netherlands. In this cross-sectional study, skin AF was measured in 957 participants, aged 20 to 77 years, with the AGE Reader. Logistic regression was used to assess associations between skin AF and the following factors: demographics, adiposity, blood lipids, fasting glucose, HbA(1c), blood pressure, dietary intake, and disease history. Stepwise linear regression was used to identify factors correlating with skin AF.Results: In males, skin AF was significantly associated with age, coffee intake, systolic and diastolic blood pressure, body fat, full fat dairy, and educational level. In females, significant associations were found with age, coffee intake, HbA(1c), diabetes, and eGFR. In the total population, current smoking was positively associated with skin AF.Conclusions: This cross-sectional study in a general population showed that age and coffee intake were associated with skin AF in both males and females. We observed a gender disparity for some of the associations with skin AF, which need to be confirmed by further research. More detailed research is needed to assess the association between skin AF and diet.

Skin autofluorescence (AF) is related to the accumulation of advanced glycation end products (AGEs) and is one of the strongest prognostic markers of mortality in hemodialysis (HD) patients. The aim of this pilot study was to investigate whether changes in skin AF appear after a single HD session and if they might be related to changes in plasma AF. Skin and plasma AF were measured before and after HD in 35 patients on maintenance HD therapy (nine women and 26 men, median age 68 years, range 33-83). Median dialysis time was 4h (range 3-5.5). Skin AF was measured noninvasively with an AGE Reader, and plasma AF was measured before and after HD at 460nm after excitation at 370nm. The HD patients had on average a 65% higher skin AF value than age-matched healthy persons (P

Skin autofluorescence (AF) is related to the accumulation of advanced glycation end products (AGEs) and is one of the strongest prognostic markers of mortality in hemodialysis (HD) patients. The ai ...

Aim Advanced glycation end products play an important role in the pathophysiology of several chronic and age-related diseases, especially diabetes mellitus. Skin autofluorescence is a non-invasive method for assessing levels of tissue advanced glycation end products. This study aims to establish the normal reference value of advanced glycation end products accumulated in tissue measured by the advanced glycation end product reader-skin autofluorescence-and discusses some factors influencing it.Methods The values of autofluorescence in healthy individuals in China were determined by the advanced glycation end product reader; age, gender, skin reflectance, smoking habits and alcohol consumption of the subjects were also recorded.Results Themean reference values of autofluorescence in healthy Chinese subjects are (95% confidence interval) 20-29 years: 1.54-1.62 arbitrary units; 30-39 years: 1.66-1.75; 40-49 years: 1.78-1.89; 50-59 years: 1.87-2.03; 60-69 years: 1.86-2.09; 70-79 years: 1.97-2.31. The value of autofluorescence is strongly related to age, but no significant difference between males and females were found (all P > 0.05). Autofluorescence was higher in smokers than in non-smokers (P Conclusions The mean reference values of autofluorescence we established could be used for a Chinese population in a clinical setting and are agreement with those in a Caucasian population. Future developments are needed to make the advanced glycation end product reader reliable for lower skin reflections as well, independently of the skin colour.

P>BackgroundSkin autofluorescence (skin AF) is determined in part by accumulation of advanced glycation end products. Increased skin AF was shown previously to predict cardiovascular events independently of conventional risk factors. We determined the association of carotid artery intima media thickness (IMT), a marker of subclinical cardiovascular disease, with skin AF in subjects without diabetes or clinically manifest cardiovascular disease.MethodsIn a cross-sectional observational study, IMT, skin AF, lipids and apolipoproteins, C-reactive protein (CRP), insulin resistance and paraoxonase-1 activity were measured in 59 non-smoking, non-obese subjects without diabetes mellitus and cardiovascular disease (32 women; 12 subjects with metabolic syndrome (MetS)).ResultsIn univariate analyses, skin AF was correlated with IMT (r = 0 center dot 265, P = 0 center dot 042), but not significantly with clinical factors, (apo)lipoproteins, CRP, insulin resistance and paraoxonase-1. In multiple linear regression analyses, IMT was determined independently by age (beta = 0 center dot 549, P ConclusionsIMT is positively related to skin AF, independently of clinical factors, (apo)lipoproteins and MetS, suggesting that skin AF represents a determinant of subclinical atherosclerosis. Increased skin AF may reflect early abnormalities in processes involved in atherosclerosis development.

Aims Previous small open label studies have shown that the advanced glycation end-product (AGE) breaker alagebrium may improve cardiac function in patients with chronic heart failure (HF). We report the design, methods and baseline characteristics of a double-blind, placebo-controlled, randomized trial evaluating the efficacy and safety of alagebrium (BENEFICIAL) in patients with HF and a left ventricular ejection fraction (LVEF) ≤ 0.45. Methods and results Patients with NYHA II–IV stable HF for at least 3 months were eligible for this study. One hundred and two patients were included in the study and randomized to either 200 mg alagebrium twice daily or placebo for a period of 36 weeks. The mean age of patients was 60 ± 11 years, 78% were male, and 17% were diabetic. Mean peak VO2 was 21.7 ± 5.9 mL/min/kg, mean LVEF was 0.32 ± 0.09. Diastolic function was worse (mean early tissue diastolic velocity (E′) 4.6 ± 1.7 vs. 6.1 ± 2.0 cm/s; P < 0.001) in patients with LVEF ≤ 0.35 compared to patients with LVEF between 0.35 and 0.45. Conclusion The BENEFICIAL study is a proof-of-concept study that will provide new data on the efficacy and safety of the AGE crosslink breaker alagebrium in systolic HF patients. EudraCT number of this trial is NCT00516646.

Advanced glycation end-products (AGEs) are molecules formed during a non-enzymatic reaction between proteins and sugar residues, called the Maillard reaction. AGEs accumulate in the human body with age, and accumulation is accelerated in the presence of diabetes mellitus. In patients with diabetes, AGE accumulation is associated with the development of cardiac dysfunction. Enhanced AGE accumulation is not restricted to patients with diabetes, but can also occur in renal failure, enhanced states of oxidative stress, and by an increased intake of AGEs. Several lines of evidence suggest that AGEs are related to the development and progression of heart failure in non-diabetic patients as well. Preliminary small intervention studies with AGE cross-link breakers in heart failure patients have shown promising results. In this review, the role of AGEs in the development of heart failure and the role of AGE intervention as a possible treatment for heart failure are discussed. (c) 2007 European Society of Cardiology. Published by Elsevier B.V All rights reserved.

Background/Purpose: Collagen is one of the major endogenous skin fluorophores. Alteration in the structure of collagen due to chronic ultraviolet radiation (UVR) exposure may influence the intensity of the autofluorescence. The aim of this study was to investigate the relation between collagen-linked autofluorescence and sun exposure to clarify whether the skin can be used as a biological UVR dosimeter. Methods: We conducted an in vivo study with 131 healthy volunteers. Fluorescence was measured from sun-exposed (dorsal forearm, forehead and shoulder) and sun-protected (buttock) skin and corrected for the impact of pigmentation and redness. The excitation wavelengths (Ex) and emission wavelengths (Em) were: Ex330:Em370, Ex330:Em455 and Ex370:Em455 nm. Individual UVR exposure data were collected both retrospectively and prospectively using questionnaires and electronic personal UVR dosimeters for a summer period. Results: Age, but not sex, skin type or smoking habits correlated significantly positively with skin autofluorescence at Ex370:Em455 at all body sites (P