Relationship between cardiac tissue glycation and skin autofluorescence in patients with coronary artery disease

Label-Free Assessment of Key Biological Autofluorophores: Material Characteristics and Opportunities for Clinical Applications

Autofluorophores are endogenous fluorescent compounds that naturally occur in the intra and extracellular spaces of all tissues and organs. Most have vital biological functions - like the metabolic cofactors NAD(P)H and FAD+, as well as the structural protein collagen. Others are considered to be waste products - like lipofuscin and advanced glycation end products - which accumulate with age and are associated with cellular dysfunction. Due to their natural fluorescence, these materials have great utility for enabling non-invasive, label-free assays with direct ties to biological function. Numerous technologies, with different advantages and drawbacks, are applied to their assessment, including fluorescence lifetime imaging microscopy, hyperspectral microscopy, and flow cytometry. Here, the applications of label-free autofluorophore assessment are reviewed for clinical and health-research applications, with specific attention to biomaterials, disease detection, surgical guidance, treatment monitoring, and tissue assessment - fields that greatly benefit from non-invasive methodologies capable of continuous, in vivo characterization.

Skin autofluorescence of advanced glycation end-products relates to new cardiovascular events in type 2 diabetes: A longitudinal observational study

BACKGROUND

Cardiovascular disease is frequent in type 2 diabetes mellitus (T2DM). We investigated the relationship between skin autofluorescence (SAF) of advanced glycation end-products and later cardiovascular events (CVEs) in patients with T2DM.

RESEARCH DESIGN AND METHODS

We conducted a retrospective analysis of 504 patients hospitalized for uncontrolled and/or complicated T2DM between 2009 and 2017. SAF was measured using an AGE-Reader. Participants were followed up from admission to December 2020, for the onset of a CVE (myocardial infarction, stroke, revascularization procedures or cardiovascular death). The relationship between SAF and CVE was analyzed by multivariable Cox regression. Log-rank curves were used to compare CVE-free survival in patients whose SAF at admission was above versus below the whole-population median. The analysis was repeated in subjects without/with macroangiopathy (defined as myocardial infarction, stroke, peripheral revascularization) at baseline.

FINDINGS

During 54 months of follow-up, 69 (13.7%) patients had a CVE. Baseline SAF was significantly higher in patients with T2DM who later experienced a CVE (2.89 ± 0.70 arbitrary units versus 2.64 ± 0.62 in others, P = 0.002). This relationship was significant after adjusting for age, sex, conventional risk factors (diabetes duration, HbA1c, arterial hypertension, dyslipidemia, smoking, body mass index), vascular complications, C-reactive protein, and treatments for diabetes. The CVE-free survival curves differed between subjects whose SAF was above the whole-population median (log-rank: P = 0.002) and those whose SAF was above the macroangiopathy-free sub-population median (log-rank: P = 0.016).

CONCLUSION

SAF of advanced glycation end-products was related to a higher incidence of later CVE in patients with T2DM.

The role of sRAGE in cardiovascular diseases

Advanced glycation end products (AGEs), by-products of glucose metabolism, have been linked to the emergence of cardiovascular disorders (CVD). AGEs can cause tissue damage in four different ways: (1) by altering protein function, (2) by crosslinking proteins, which makes tissue stiffer, (3) by causing the generation of free radicals, and (4) by activating an inflammatory response after binding particular AGE receptors, such as the receptor for advanced glycation end products (RAGE). It is suggested that the soluble form of RAGE (sRAGE) blocks ligand-mediated pro-inflammatory and oxidant activities by serving as a decoy. Therefore, several studies have investigated the possible anti-inflammatory and anti-oxidant characteristics of sRAGE, which may help lower the risk of CVD. According to the results of various studies, the relationship between circulating sRAGE, cRAGE, and esRAGE and CVD is inconsistent. To establish the potential function of sRAGE as a therapeutic target in the treatment of cardiovascular illnesses, additional studies are required to better understand the relationship between sRAGE and CVD. In this review, we explored the potential function of sRAGE in different CVD, highlighting unanswered concerns and outlining the possibilities for further investigation.

Advanced glycation end-products, cardiac function and heart failure in the general population: The Rotterdam Study

AIMS/HYPOTHESIS

The aim of this work was to assess the association of advanced glycation end-products (AGEs), measured by skin autofluorescence (SAF), with prevalent heart failure, and with systolic and diastolic cardiac function, in a large population-based cohort study.

METHODS

We assessed the cross-sectional association between SAF and prevalent heart failure among 2426 participants from the population-based Rotterdam Study, using logistic regression. Next, among individuals free of heart failure (N=2362), we examined the link between SAF (on a continuous scale) and echocardiographic parameters of left ventricular (LV) systolic and diastolic function using linear regressions. Analyses were adjusted for traditional cardiovascular risk factors.

RESULTS

Higher levels of SAF were associated with higher odds of prevalent heart failure (multivariable adjusted OR 2.90 [95% CI 1.80, 4.62] for one unit higher SAF value). Among individuals without heart failure, one unit increase in SAF was associated with 0.98% lower LV ejection fraction (mean difference [β] -0.98% [95% CI -1.45%, -0.50%]). The association was stronger among participants with diabetes (β -1.84% [95% CI -3.10%, -0.58%] and β -0.78% [95% CI -1.29%, -0.27%] among participants with and without diabetes, respectively). Associations of SAF with diastolic function parameters were not apparent, except in men with diabetes.

CONCLUSIONS/INTERPRETATION

AGE accumulation was independently associated with prevalent heart failure. Among individuals free of heart failure, AGEs were associated with cardiac function, in particular systolic function. This association was present in participants with and without diabetes and was more prominent in those with diabetes.

The relationship of skin autofluorescence with diastolic function and HFA-PEFF score in a general population of older people

BACKGROUND AND AIMS

Advanced glycation end-products accumulation in tissue as measured by Skin autofluorescence (SAF) is related to diastolic function in specific patient populations. This analysis aims at investigating this relationship in a general population of older persons.

METHODS AND RESULTS

Based on data from the CARLA cohort at first follow-up, 245 subjects were analyzed and stratified according to cardiovascular risk factors (CVRF). We used linear regression to investigate the association between diastolic function evaluated by echocardiography, HFA-PEFF score, and SAF. Univariable regression analysis showed an association of SAF with septal-E/e' (standardised beta = 1.11, 95% CI = 0.51-1.71) and A (3.42, 95% CI = 0.72-6.12), the former persisting after adjustment for age, sex and CVRF (0.67, 95% CI = 0.05-1.28). Septal-E/e' remained related to SAF only in the high cardiovascular risk stratum (1.16, 95% CI = 0.26-2.06). SAF was related to HFA-PEFF score (0.27, 95% CI = 0.10-0.43) but not after correcting for age and sex (0.16, 95% CI = 0.00-0.32) and CVRF and glomerular filtration rate (0.12, 95% CI = -0.07 - 0.27). SAF was related to the HFA-PEFF score only for participants with high cardiovascular risk (0.23, 95% CI = 0.02-0.45).

CONCLUSION

In a general community-dwelling older population, SAF is related to diastolic function as measured by septal-E/e'. Further research is necessary to assess if SAF is a potential screening tool for diastolic dysfunction in advanced age.

Toxin Removal and Inflammatory State Modulation during Online Hemodiafiltration Using Two Different Dialyzers (TRIAD2 Study)

Uremic toxins play a pathological role in atherosclerosis and represent an important risk factor in dialysis patients. Online hemodiafiltration (HDF) has been introduced to improve the clearance of middle- and large-molecular-weight solutes (>500 Da) and has been associated with reduced cardiovascular mortality compared to standard hemodialysis. This non-randomized, open-label observational study will explore the efficacy of two dialyzers currently used for online HDF, a polysulfone-based high-flux membrane, and a cellulose triacetate membrane, in hemodialysis patients with signs of middle-molecule intoxication or intradialytic hypotension. In particular, the two filters will be evaluated for their ability in uremic toxin removal and modulation of inflammatory status. Sixteen subjects in standard chronic bicarbonate hemodialysis requiring a switch to online HDF in view of their clinical status will be enrolled and divided into two treatment arms, according to the previous history of hypersensitivity to polysulfone/polyethersulfone dialysis filters and hypersensitivity to drugs or other allergens. Group A will consist of 16 patients without a previous history of hypersensitivity and will be treated with a polysulfone filter (Helixone FX100), and group B, also consisting of 16 patients, with a previous history of hypersensitivity and will be treated with asymmetric triacetate (ATA; SOLACEA 21-H) dialyzer. Each patient will be followed for a period of 24 months, with monthly assessments of circulating middle-weight toxins and protein-bound toxins, markers of inflammation and oxidative stress, lymphocyte subsets, activated lymphocytes, and monocytes, cell apoptosis, the accumulation of advanced glycation end-products (AGEs), variations in arterial stiffens measured by pulse wave velocity (PWV), and mortality rate. The in vitro effect on endothelial cells of uremic serum collected from patients treated with the two different dialyzers will also be investigated to examine the changes in angiogenesis, cell migration, differentiation, apoptosis and proliferative potential, and gene and protein expression profile. The expected results will be a better awareness of the different effects of polysulfone gold-standard membrane for online HDF and the new ATA membrane on the removal of uremic toxins removal and inflammation due to blood-membrane interaction.

Drug-drug interactions between salvianolate injection and aspirin based on their metabolic enzymes

BACKGROUND

It is unclear whether the combination of traditional Chinese medicine and Western medicine leads to interactions in pharmacokinetics (PKs) and pharmacodynamics (PDs). In this study, the influence of salvianolate and aspirin on metabolic enzymes, and the relationship between the blood concentration and pharmacodynamic indexes, were determined.

METHOD

In this, randomized, parallel-grouped, single-center clinical trial, 18 patients with coronary heart disease were randomly allocated into three groups: aspirin (AP) group, salvianolate (SV) group, and combination (A + S) group. All treatment courses lasted for 10 days, and blood samples were acquired before and after administration at different timepoints. The expression of catechol-O-methyltransferase (COMT), CD62p, procaspase-activating compound 1 (PAC-1), P2Y12, phosphodiesterase, and mitogen-activated protein kinase 8 (MAPK8) were compared with variance analysis The blood concentrations were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry.

RESULTS

Sixteen subjects completed the study. No significant difference in COMT was found among groups, although there was a decrease in the SV group. The PK results indicated that the absorption time of salicylic acid was shortened and the AUC_0-∞ decreased and the elimination time of salvianolic acid B was prolonged and the AUC_0-∞ decreased. The PD results declined after administration. A significant difference was found in MAPK8, CD62p, and P2Y12 expression. Compared with the SV group, a significant difference in P2Y12 in the A + S group was found.

CONCLUSION

A pharmacokinetic drug-drug interaction was found in the aspirin and salvianolate combination. Pharmacodynamically, there was no difference between the A + S and AP groups. However, P2Y12 expression in the combination group was superior to that in the SV group.

TRIAL REGISTRATION NUMBERS

The trial was registered on October 9, 2017, ClinicalTrials.gov, NCT03306550. https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0007D8H&selectaction=Edit&uid=U0003QY8&ts=2&cx=oiuc9g.

Skin Autofluorescence as a Predictor of First Heart Failure Hospitalization in Patients With Heart Failure With Preserved Ejection Fraction

Background

An autofluorescence (AF) reader can be used to diagnose skin AF non-invasively by measuring local accumulation of advanced glycation end-products. A number of studies have investigated the relationships between skin AF and cardiovascular disease. However, data regarding the usefulness of skin AF as a predictor of chronic heart failure remain limited. This prospective study aimed to elucidate the usefulness of skin AF as a predictor of first heart failure (HF) hospitalization in patients with HF with preserved ejection fraction (HFpEF).

Methods

A total of 412 outpatients with HFpEF with no history of HF hospitalization were enrolled. Patients were assigned to either the low (group L; skin AF ≤ 2.9 arbitrary units (AU); n = 303) or the high (group H; skin AF ≥ 3.0 AU; n = 109) group according to optimal skin AF cut-off levels determined using receiver operating characteristic curves. Clinical parameters and the usefulness of skin AF as a predictor of first HF hospitalization were evaluated.

Results

The E/e' ratio as a marker of left ventricular diastolic function was significantly higher in group H patients than in group L patients at baseline (group H, 11.8 ± 3.8; group L, 10.6 ± 3.3; P = 0.002). During the 72.7-month follow-up period, 43 HF cases were hospitalized (group L, 15 cases; group H, 28 cases; P < 0.001, log-rank test). Multivariate Cox regression analyses revealed that group H exhibited a significantly higher risk of first HF hospitalization than did group L (hazard ratio, 2.26; 95% confidence interval, 1.21 - 3.52; P = 0.014).

Conclusions

The present study demonstrated that skin AF can predict the risk of first HF hospitalization in patients with HFpEF. Prospective studies, including intervention therapies, are required to validate our observations.

It's all in our skin-Skin autofluorescence-A promising outcome predictor in cardiac surgery: A single centre cohort study

BACKGROUND

The optimum risk score determining perioperative mortality and morbidity in cardiac surgery remains debated. Advanced glycation end products (AGEs) derived from glycaemic and oxidative stress accumulate to a comparable amount in skin and the cardiovascular system leading to a decline in organ function. We aimed to study the association between AGE accumulation measured as skin autofluorescence (sAF) and the outcome of cardiac surgery patients.

METHODS

Between April 2008 and November 2016, data from 758 consecutive patients undergoing coronary artery bypass grafting, aortic valve replacement or a combined procedure were analyzed. Skin autofluorescence was measured using an autofluorescence reader. Beside mortality, for the combined categorical morbidity outcome of each patient failure of the cardiac-, pulmonary-, renal- and cerebral system, as well as reoperation and wound healing disorders were counted. Patients without or with only one of the outcomes were assigned zero points whereas more than one outcome failure resulted in one point. Odds ratios (ORs) were estimated in multivariable logistic regression analysis with other preoperative parameters and the established cardiac surgery risk score systems EuroSCORE II and STS score.

RESULTS

Skin autofluorescence as non-invasive marker of tissue glycation provided the best prognostic value in identifying patients with major morbidity risks after cardiac surgery (OR = 3.13; 95%CI 2.16-4.54). With respect to mortality prediction the STS score (OR = 1.24; 95%CI 1.03-1.5) was superior compared to the EuroSCORE II (OR = 1.17: 95%CI 0.96-1.43), but not superior when compared to sAF (OR = 6.04; 95%CI 2.44-14.95).

CONCLUSION

This finding suggests that skin autofluorescence is a good biomarker candidate to assess the perioperative risk of patients in cardiac surgery. Since the EuroSCORE does not contain a morbidity component, in our view further sAF measurement is an option.

Recent Advances and the Potential for Clinical Use of Autofluorescence Detection of Extra-Ophthalmic Tissues

The autofluorescence (AF) characteristics of endogenous fluorophores allow the label-free assessment and visualization of cells and tissues of the human body. While AF imaging (AFI) is well-established in ophthalmology, its clinical applications are steadily expanding to other disciplines. This review summarizes clinical advances of AF techniques published during the past decade. A systematic search of the MEDLINE database and Cochrane Library databases was performed to identify clinical AF studies in extra-ophthalmic tissues. In total, 1097 articles were identified, of which 113 from internal medicine, surgery, oral medicine, and dermatology were reviewed. While comparable technological standards exist in diabetology and cardiology, in all other disciplines, comparability between studies is limited due to the number of differing AF techniques and non-standardized imaging and data analysis. Clear evidence was found for skin AF as a surrogate for blood glucose homeostasis or cardiovascular risk grading. In thyroid surgery, foremost, less experienced surgeons may benefit from the AF-guided intraoperative separation of parathyroid from thyroid tissue. There is a growing interest in AF techniques in clinical disciplines, and promising advances have been made during the past decade. However, further research and development are mandatory to overcome the existing limitations and to maximize the clinical benefits.

The different roles for the advanced glycation end products axis in heart failure and acute coronary syndrome settings

AIMS

This work aimed to compare the behavior of the advanced glycation end products (AGEs) and their soluble receptor (sRAGE) in two cohorts of patients: those with heart failure (HF) and acute coronary syndrome (ACS).

METHODS AND RESULTS

A unicentric observational clinical study was performed in 102 patients with ACS and 102 patients with chronic HF matched by age and gender. At inclusion, fluorescent AGEs were measured by quantitative fluorescence spectroscopy of plasma, and total sRAGE and endogenous secretory RAGE (esRAGE) levels were determined by enzyme-linked immunosorbent assay kits. A 5-year follow-up period was established for recording cardiac death (primary endpoint) and the incidence of non-fatal myocardial infarction or HF readmission (secondary endpoints). Higher glycation parameters were observed in HF patients, whereas no differences in sRAGE forms were found between HF and ACS cohorts, except for cRAGE, which was higher in HF. Associations between glycation parameters and sRAGE forms were observed in HF, but not in ACS. Differences were also evidenced in the long-term prognosis of each cohort: esRAGE showed an independent prognostic value for cardiac death or non-fatal cardiovascular events in HF, but none of the AGE-RAGE variables were predictors in ACS.

CONCLUSIONS

A different role for the AGE-RAGE axis was observed in HF and ACS. All the sRAGE forms were directly related with glycation parameters in HF, but not in ACS. The independent value of the sRAGE forms on each cardiovascular disease was supported by esRAGE being an independent predictor of bad long-term prognosis only for HF.

Clinical Significance of Skin Autofluorescence in Elderly Patients With Long-Standing Persistent Atrial Fibrillation

Background

Recent clinical studies have demonstrated the importance of skin autofluorescence as a cardiovascular risk factor. However, data regarding the relationship between skin autofluorescence and atrial fibrillation are limited. The aim of this study was to clarify the clinical significance of skin autofluorescence in elderly patients with long-standing persistent atrial fibrillation.

Methods

This cross-sectional study enrolled 112 elderly patients with long-standing persistent atrial fibrillation who were treated medically (46 men and 66 women; mean age, 81 ± 9 years). The association between skin autofluorescence and various clinical parameters was examined.

Results

Significant relationships were observed between skin autofluorescence and CHADS₂ score (r = 0.53, P < 0.001), high-sensitivity cardiac troponin T level (r = 0.43, P < 0.001), reactive oxygen metabolite levels (r = 0.52, P < 0.001), and whole blood passage time (r = 0.45, P < 0.001). Furthermore, multiple regression analyses showed that these clinical parameters were independent variables when skin autofluorescence was used as a subordinate factor. Receiver-operating characteristic curve analysis indicated that the risk values of skin autofluorescence for high CHADS₂ scores (≥ 2) or elevated high-sensitivity cardiac troponin T levels (> 0.014ng/mL) were 2.6 arbitrary units (AU) and 2.7 AU, respectively.

Conclusions

The findings of this study indicated that skin autofluorescence may be a prognostic factor in elderly patients with long-standing persistent atrial fibrillation. The risk value of skin autofluorescence was considered as 2.6 AU or 2.7 AU.

Skin Intrinsic Fluorescence and Selected Measures of Visual Function and aging in Older Adults

Purpose: Functional, structural and metabolic decline in many systems and in combination contribute to biologic aging and may be manifest as increased risk of morbid events such as neuropathy, albuminuria, and coronary artery disease or mortality. A biologic marker of aging may be a useful tool in identifying persons at increased risk of morbidity or mortality. We have measured skin intrinsic fluorescence (SIF) in a group of older adults to determine whether this easily determined measure could serve as such a biomarker. Methods: Survivors of a population based study of older adults in a moderate sized Midwestern town. Of the 1181 persons participating, 939 had measures of skin intrinsic fluorescence (SIF) and at least one functional or diagnostic characteristic at the most recent examination. Characteristics such as blood pressure, forced expiratory volume, vision, time to walk a standard course and medical history and their associations with SIF measures were examined. Mortality after the last examination with respect to SIF was also investigated. There were 118 deaths among those who participated in this phase of the study. All analyses pertinent to these findings were adjusted for age. Results: SIF measures were significantly associated with low contrast sensitivity, more errors on frequency doubling technology testing (loss of peripheral vision), self-reported poor vision, slow gait, poor forced expiratory volume, and self-reported poor health. SIF was also associated with increased risk of death. All of these analyses were adjusted for age. Conclusions: Skin intrinsic fluorescence provides easily obtained markers of age-related functional outcomes, suggesting SIF measurements may be useful to identify persons who may benefit from more frequent medical scrutiny to decrease morbidity and mortality.

Glycated proteins in nutrition: Friend or foe?

Advanced glycation end products (AGEs) are formed in in vivo, and accumulate in tissues and body fluids during ageing. Endogenous AGE-modified proteins show altered structure and function, and may interact with receptor for AGEs (RAGE) resulting in production of reactive oxygen species, inflammatory, atherogenic and diabetogenic responses. AGEs are also formed in thermally processed foods. Studies in rodents document that dietary AGEs are partially absorbed into circulation, and accumulate in different tissues. Knowledge on the health effects of high dietary intake of AGEs is incomplete and contradictory. In this overview we discuss the data from experimental and clinical studies, either those supporting the assumption that restriction of dietary AGEs associated with health benefits, or data suggesting that dietary intake of AGEs associates with positive health outcomes. We polemicize whether the effects of exaggerated intake or restriction of highly thermally processed foods might be straightforward interpreted as the effects of AGEs-rich vs. AGEs-restricted diets. We also underline the lack of studies, and thus a poor knowledge, on the effects of different single chemically defined AGEs administration, concurrent intake of different dietary AGEs, of load with dietary AGEs corresponding to the habitual diet in humans, and on those of dietary AGEs in vulnerable populations, such as infants and particularly elderly.

Skin autofluorescence is associated with high-sensitive cardiac troponin T, a circulating cardiac biomarker, in Japanese patients with diabetes: A cross-sectional study

The study aims to evaluate the relationship between skin autofluorescence, a marker of advanced glycated end-products accumulation in tissue, and high-sensitive cardiac troponin T, a cardiovascular biomarker, in Japanese subjects with diabetes. A total of 145 subjects with diabetes and 32 nondiabetic subjects as control attending the outpatient clinic were examined. Skin autofluorescence was measured using the AGE Reader™. Univariate and multivariate regression analyses were used to identify the factors associated with the high-sensitive cardiac troponin T and N-terminal pro-B-type natriuretic peptide values. Skin autofluorescence, high-sensitive cardiac troponin T, and maximum intima-media thickness values were significantly higher in subjects with diabetes than in nondiabetic subjects. Diabetic subjects with skin autofluorescence level⩾2.47 AU (median value) had higher levels of N-terminal pro-B-type natriuretic peptide ( p = 0.006), high-sensitive cardiac troponin T ( p < 0.0001), pentosidine ( p = 0.011) and maximum intima-media thickness ( p = 0.017) compared to those with skin autofluorescence level <2.47 AU. A multivariate regression analysis using variables that were significantly correlated with high-sensitive cardiac troponin T and N-terminal pro-B-type natriuretic peptide, revealed that estimated glomerular filtration rate (β = -0.364, p < 0.001) and skin autofluorescence (β = 0.254, p  = 0.0022) were independent determinants of high-sensitive cardiac troponin T, but the variables that were significant in the univariate analysis were no longer predictors for N-terminal pro-B-type natriuretic peptide. Skin autofluorescence measured with the AGE Reader™ could be an easy and noninvasive surrogate marker for identifying diabetic subjects at high risk for subclinical cardiac injury.

Clinical Impact of Hemorheology on Subclinical Myocardial Injury in Patients with Hypertension

Background

The blood concentration of high-sensitivity cardiac troponin T (hs-cTnT) is a useful biomarker for myocardial injury or the pathogenesis of hypertension. Little is known about the relationship between hemorheology and myocardial injury in patients with hypertension. This cross-sectional study aimed to clarify the clinical impact of hemorheology on subclinical myocardial injury assessed with a microchannel array flow analyzer (MC-FAN) and its impact on hs-cTnT in patients with hypertension.

Methods

A total of 447 outpatients (men: 181; women: 266; mean age: 65 ± 13 years), with no history of cardiovascular disease, including admission for heart failure, who were undergoing treatment for hypertension, were enrolled. Whole blood passage time (WBPT) as a marker of hemorheology was measured with a MC-FAN, and the relationship between hs-cTnT levels and various clinical parameters, including WBPT, was examined.

Results

hs-cTnT levels were detected in 400 patients (89.5%). WBPT was significantly higher in patients with detectable hs-cTnT levels than in those with undetectable hs-cTnT levels (60.5 ± 16.8 s versus 50.2 ± 14.2 s, P < 0.001). In patients with detectable hs-cTnT levels, there was a significant positive correlation between WBPT and hs-cTnT level (r = 0.33; P < 0.001). Multiple regression analysis revealed that WBPT was an independent variable when hs-cTnT was a subordinate factor (β = 0.15; P < 0.01). Receiver-operating characteristic curve analysis indicated that a cutoff value for WBPT of 55.6 s yielded the largest area under the curve (0.744; P < 0.001) for discriminating high hs-cTnT levels as ≥ 0.014 ng/mL.

Conclusion

The results indicate that WBPT is independently associated with hs-cTnT in hypertensive patients with no history of cardiovascular events, suggesting that impairment of hemorheology in small cardiac vessels causes subclinical myocardial injury. In addition, the study suggests that progression of myocardial injury can be prevented by maintaining WBPT at approximately ≤ 55 s.

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.

Clinical Significance of Skin Autofluorescence in Patients With Type 2 Diabetes Mellitus With Chronic Heart Failure

Background

Recent clinical studies have shown that skin autofluorescence (AF) levels are significantly associated with diabetic complications. In contrast, data regarding the relationships between skin AF and chronic heart failure (CHF) are limited. The aim of this study was to clarify the clinical significance of skin AF in patients with type 2 diabetes mellitus (DM) with CHF.

Methods

This cross-sectional study enrolled 257 outpatients with type 2 DM with CHF who were treated medically (96 men and 161 women; mean age, 79 ± 7 years). Associations between skin AF and various clinical parameters were examined.

Results

Incidence of skin AF in patients with a history of hospitalization due to HF was significantly higher than in those without a history of hospitalization due to HF (3.0 ± 0.5 AU vs. 2.7 ± 0.5 AU, respectively, P < 0.001). Significant positive correlations were found between skin AF and various clinical parameters, such as E/e′ as a maker of left ventricular diastolic function (r = 0.30, P < 0.001), high-sensitivity cardiac troponin T levels as a marker of myocardial injury (r = 0.45, P < 0.001), reactive oxygen metabolite levels as an oxidative stress marker (r = 0.31, P < 0.001), and cardio-ankle vascular index as a marker of arterial function (r = 0.38, P < 0.001). Furthermore, multiple regression analyses showed that these clinical parameters (E/e′ (β = 0.25, P < 0.001)), high-sensitivity cardiac troponin T levels (β = 0.30, P < 0.001), cardio-ankle vascular index (β = 0.21, P < 0.001), reactive oxygen metabolite levels (β = 0.15, P < 0.01), and a history of hospitalization due to HF (β = 0.23, P < 0.001) were independent variables when skin AF was used as a subordinate factor.

Conclusion

The findings of this study showed that skin AF may be a determining factor for prognosis in patients with type 2 DM with CHF. Further investigations in a large prospective study, including intervention therapies, are required to validate the results of this study.

The association between skin auto-fluorescence of palmoplantar sites and microvascular complications in Asian patients with type 2 diabetes mellitus

Skin auto-fluorescence (SAF) has generated broad interest about the prospects for non-invasive advanced glycation end product assessment and its direct interplay with the development of microvascular complications, but clinical application of the existing SAF measuring of non-palmoplantar sites in non-Caucasian subjects with dark skin type is still controversial. Here, we tested the diabetic complication screening performance of a novel SAF measuring system in Asian type 2 diabetes mellitus (T2DM) subjects. A total of 166 Korean patients with T2DM were enrolled in this study and palmoplantar SAF was measured by a newly developed transmission-geometry noninvasive optical system. We found that transmitted SAF values of palmoplantar sites, 1st dorsal interossei muscles of the hand, in a complication group were significantly higher than in a non-complication group while no differences were observed between the two groups in reflected SAF of non-palmoplantar sites. The transmitted SAF values of palmoplantar sites were dramatically increased in subjects with multiple complications and were tightly correlated with the duration of microvascular complications. In conclusion, the SAF measurement in the palmoplantar sites with a non-invasive transmission-geometry optical system provided better microvascular complication screening performance compared to the SAF measurement of non-palmoplantar sites specifically in Asian T2DM subjects.

Association of Hemorheology With High-Sensitivity Cardiac Troponin T Levels in Patients With Type 2 Diabetes Mellitus Assessed by Microchannel Array Flow Analyzer

Background

Recent studies on high-sensitivity cardiac troponin T (hs-cTnT) and whole blood passage time (WBPT), estimated by hemorheology assessed with the microchannel array flow analyzer (MC-FAN), have revealed the significance of cardiovascular risk factors. However, there are no known reports on the relationship between these two clinical parameters. This cross-sectional study aimed to clarify the associations between WBPT and hs-cTnT levels in patients with type 2 diabetes mellitus from the perspective of subclinical myocardial injury or the primary prevention of cardiovascular events.

Methods

A total of 301 outpatients (men, 116; women, 185; mean age, 65 ± 11 years), with no history of cardiovascular diseases, undergoing treatment for diabetes mellitus were enrolled. Hs-cTnT levels and WBPT were measured using a commercial device, and the relationship between hs-cTnT levels and various clinical parameters, including WBPT, was examined.

Results

Hs-cTnT levels were detected in 261 (86.7%) patients. WBPT was significantly higher in patients with detectable hs-cTnT levels than in those with undetectable hs-cTnT levels (64 ± 18 s vs. 51 ± 13 s, P < 0.001). In patients with detectable hs-cTnT levels, there was a significantly positive correlation between WBPT and hs-cTnT levels (r = 0.40; P < 0.001). Furthermore, multiple regression analysis revealed that WBPT (β = 0.24; P < 0.001) was an independent variable when hs-cTnT was a subordinate factor. Conversely, patients with high (≥ 70 s; odds ratio, 5.3 (95% CI, 1.6 - 16.1); P < 0.01) and median (50.2 - 69.8 s; odds ratio, 3.8 (95% CI, 1.2 - 12.4); P < 0.05) WBPT had a significantly higher risk for high hs-cTnT levels (≥ 0.014 ng/mL) than those with low WBPT (≤ 50.0 s).

Conclusions

The results of this study indicated independent associations of hemorheology with hs-cTnT in patients with type 2 diabetes mellitus assessed by MC-FAN. We suggest that an increase in hs-cTnT levels can be prevented by maintaining WBPT at ≤ 50.0 s.

Clinical impact of skin autofluorescence on high-sensitivity troponin T in hypertensive patients

Background

Recent studies have reported the importance of high-sensitivity troponin T (hs-cTnT) or skin autofluorescence (AF) as a cardiovascular risk factor. However, little is known about the relationship between these two markers. The aim of this study was to clarify the clinical impact of skin AF on hs-cTnT in hypertensive patients, from the perspective of primary prevention of cardiovascular events.

Methods

In total, 457 outpatients on treatment for hypertension [182 men and 275 women; mean (± SD) age, 67 ± 13 y] and with no history of cardiovascular events were enrolled. Hs-cTnT levels and skin AF were measured using commercial devices, and relationships between hs-cTnT levels and various clinical parameters including skin AF were examined.

Results

Hs-cTnT was detected in 405 (88.6%) patients. Skin AF was significantly higher in patients with detectable hs-cTnT than in those without detectable hs-cTnT [2.6 ± 0.5 arbitrary units (AU) vs. 2.2 ± 0.5 AU, respectively, p < 0.001]. In patients with detectable hs-cTnT, there was a significantly positive correlation between skin AF and Log-hs-cTnT (r = 0.41, p < 0.001). Furthermore, multiple regression analysis revealed that skin AF was the strongest variable associated with Log-hs-cTnT as a subordinate factor (β = 0.30, p < 0.001).

Conclusions

The results of this study indicate that skin AF is an important determining factor for hs-cTnT elevation in hypertensive patients with no history of cardiovascular events.

Skin accumulation of advanced glycation end products is increased in patients with an abdominal aortic aneurysm

OBJECTIVE

Advanced glycation end products (AGEs) are implicated in the pathogenesis of cardiovascular disease. Accumulation of AGEs is driven by oxidative or glycemic stress and can be assessed by skin autofluorescence (SAF). SAF is increased in patients with peripheral artery disease (PAD) and independently associated with mortality and major adverse cardiovascular events in these patients. PAD and abdominal aortic aneurysm (AAA) share several risk factors. Inflammation is an important process in AAA formation and increases levels of oxidative stress. We therefore hypothesized that SAF would be increased in AAA patients compared with controls.

METHODS

A case-control study was performed in 248 AAA patients and 124 controls without AAA or PAD matched for age and presence of diabetes mellitus. SAF was noninvasively assessed with the AGE Reader (Diagnoptics Technologies BV, Groningen, The Netherlands).

RESULTS

SAF was higher in AAA patients than in controls: 2.89 ± 0.63 vs 2.68 ± 0.63 arbitrary units (P = .003). PAD comorbidity was associated with increased SAF within the AAA patient group (P = .01). After correction for known factors influencing SAF (age, current smoking, hypertension, and estimated glomerular filtration rate), PAD comorbidity remained an independent determinant of SAF. Logistic regression analysis of the total cohort showed an unadjusted odds ratio (OR) of 1.74 (95% confidence interval [CI], 1.20-2.51) for the presence of AAA with each unit increase of SAF and an adjusted OR of 1.78 (95% CI, 1.22-2.60) after correction for cardiovascular comorbidity (cerebrovascular disease and coronary artery disease). After additional correction for sex, current smoking, hypertension, and use of lipid-lowering drugs, this significance was lost (adjusted OR, 1.53; 95% CI, 0.94-2.48).

CONCLUSIONS

Skin accumulation of AGEs, measured by SAF, is increased in patients with AAA compared with controls without AAA or PAD, independent of the presence of coronary artery disease and cerebrovascular disease. In AAA patients, SAF is closely associated with the presence of PAD and cardiovascular risk factors.

Diverging effects of diabetes mellitus in patients with peripheral artery disease and abdominal aortic aneurysm and the role of advanced glycation end-products: ARTERY study - protocol for a multicentre cross-sectional study

INTRODUCTION

Diabetes mellitus is a well-defined risk factor for peripheral artery disease (PAD), but protects against the development and growth of abdominal aortic aneurysm (AAA). Diabetes mellitus is associated with arterial stiffening and peripheral arterial media sclerosis. Advanced glycation end-products (AGEs) are increased in diabetes mellitus and cardiovascular disease. AGEs are known to form cross-links between proteins and are associated with arterial stiffness. Whether AGEs contribute to the protective effects of diabetes mellitus in AAA is unknown. Therefore, the ARTERY (Advanced glycation end-pRoducts in patients with peripheral arTery disEase and abdominal aoRtic aneurYsm) study is designed to evaluate the role of AGEs in the diverging effects of diabetes mellitus on AAA and PAD.

METHODS AND ANALYSIS

This cross-sectional multicentre study will compare the amount, type and location of AGEs in the arterial wall in a total of 120 patients with AAA or PAD with and without diabetes mellitus (n=30 per subgroup). Also, local and systemic vascular parameters, including pulse wave velocity, will be measured to evaluate the association between arterial stiffness and AGEs. Finally, AGEs will be measured in serum, urine, and assessed in skin with skin autofluorescence using the AGE Reader.

ETHICS AND DISSEMINATION

This study is approved by the Medical Ethics committees of University Medical Center Groningen, Martini Hospital and Medisch Spectrum Twente, the Netherlands. Study results will be disseminated through peer-reviewed journals and scientific events.

TRIAL REGISTRATION NUMBER

trialregister.nl NTR 5363.

Is Diabetic Skeletal Fragility Associated with Microvascular Complications in Bone?

PURPOSE OF REVIEW

The objective of this literature review is to determine whether there are indications that microvascular complications occur in diabetic bone. Evidence definitively linking diabetic skeletal fragility with microvascular complications in bone remains elusive.

RECENT FINDINGS

Circumstantial evidence, some recent and some lost to time, suggests that atherosclerotic vascular diseases such as peripheral arterial disease cause poor blood perfusion of bone and subsequent hypoxia and contribute to low bone density and high cortical porosity, patterns similar to some recently observed in diabetic subjects. Evidence also exists to suggest that potentially anti-angiogenic conditions, such as impaired vascular endothelial growth factor (VEGF) signaling, predominate in diabetic bone. Microvascular complications may contribute, in part, to diabetic skeletal fragility but data supporting this interpretation are primarily circumstantial at this time. This review highlights gaps in our knowledge and hopefully spurs further discussions and research on this topic.

Skin autofluorescence is associated with inappropriate left ventricular mass and diastolic dysfunction in subjects at risk for cardiovascular disease

Background

Enhanced advanced glycation end products deposition within myocardial tissue may cause diastolic dysfunction. However, whether this is related to left ventricular hypertrophy or inappropriate left ventricular mass remains unclear.

Methods

We prospectively enrolled 139 subjects at risk for cardiovascular diseases. We used echocardiography for measurements of left ventricular mass and cardiac systolic and diastolic functional parameters. An advanced glycation end product reader was applied for measurements of skin autofluorescence values. Comparisons of left ventricular mass and echocardiographic parameters between the higher and lower skin autofluorescence groups were analyzed.

Results

Compared with the lower skin autofluorescence group, left ventricular mass index and the ratio of observed left ventricular mass/predicted left ventricular mass (oLVM/pLVM) was significantly higher in the higher skin autofluorescence group (61.22 ± 17.76 vs. 47.72 ± 11.62, P < 0.01, 1.62 ± 0.38 vs. 1.21 ± 0.21, P < 0.01). After adjustment for potential confounding factors, skin autofluorescence was an independent factor for left ventricular mass index (β = 0.32, P < 0.01) and the ratio of oLVM/pLVM (β = 0.41, P < 0.01). Skin autofluorescence ≥2.35 arbitrary unit predicted left ventricular hypertrophy at a sensitivity of 58.8%, and a specificity of 73.0% (P < 0.01). Skin autofluorescence ≥2.25 arbitrary unit predicted inappropriate left ventricular mass at a sensitivity of 71.1%, and a specificity of 83.9% (P < 0.01). Skin autofluorescence was positively correlated with E/E′, an indicator for diastolic dysfunction (r = 0.21, P = 0.01).

Conclusions

Skin autofluorescence is a useful tool for detecting left ventricular hypertrophy, inappropriate left ventricular mass and diastolic dysfunction.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0495-9) contains supplementary material, which is available to authorized users.

Effect of glycation inhibitors on aging and age-related diseases

Vast evidence supports the view that glycation of proteins is one of the main factors contributing to aging and is an important element of etiopathology of age-related diseases, especially type 2 diabetes mellitus, cataract and neurodegenerative diseases. Counteracting glycation can therefore be a means of increasing both the lifespan and healthspan. In this review, accumulation of glycation products during aging is presented, pathophysiological effects of glycation are discussed and ways of attenuation of the effects of glycation are described, concentrating on prevention of glycation. The effects of glycation and glycation inhibitors on the course of selected age-related diseases, such as Alzheimer's disease, Parkinson's disease and cataract are also reviewed.

Skin autofluorescence predicts cardio-renal outcome in type 1 diabetes: a longitudinal study

Background

We aimed to analyze the relationships between skin autofluorescence (SAF) and incident macrovascular events and renal impairment after 4 years of follow-up in patients with type 1 diabetes (T1D).

Methods

Two hundred and forty-three patients (51.2 ± 16.7 years old) with T1D participated. SAF was measured by AGE-Reader-TM at inclusion. Macrovascular events (MVE), estimated glomerular filtration rate (eGFR) and urinary albumin excretion rate (AER) were recorded then and 4 years later. Multivariate logistic regression was used to analyze the relationships between SAF and incident MVE and renal profile 4 years later.

Results

Patients with incident MVE had a higher SAF (p = 0.003). SAF predicted incident MVE after adjustment for age, sex, body mass index, tobacco, diabetes duration, hypertension, HbA_1c, AER, eGFR (OR 4.84 [95 % CI 1.31–17.89], p = 0.018). However, this relation was no longer significant after adjustment for history of MVE. An inverse relation was found between SAF and incident eGFR (p = 0.0001). Patients with incident eGFR <60 ml/min/1.73 m² had a SAF higher than patients with normal eGFR. After adjustment for the previous criteria, SAF remained associated with the risk of impaired incident eGFR (OR 7.42 [95 % CI 1.59–34.65], p = 0.018). No relation was found between SAF and increased AER 4 years later.

Conclusions

SAF predicts MVE in patients with T1D, adjusted for cardiovascular risk factors but the most powerful predictive factor remains history of MVE. SAF also predicts eGFR impairment, adjusted for initial AER and renal function. SAF could be a useful non-invasive tool for estimating risk of cardiovascular or renal impairment in patients with T1D.

Skin fluorescence as a clinical tool for non-invasive assessment of advanced glycation and long-term complications of diabetes

Glycation is important in the development of complications of diabetes mellitus and may have a central role in the well-described glycaemic memory effect in developing these complications. Skin fluorescence has emerged over the last decade as a non-invasive method for assessing accumulation of advanced glycation endproducts. Skin fluorescence is independently related to micro- and macrovascular complications in both type 1 and type 2 diabetes mellitus and is associated with mortality in type 2 diabetes. The relation between skin fluorescence and cardiovascular disease also extends to other conditions with increased tissue AGE levels, such as renal failure. Besides cardiovascular complications, skin fluorescence has been associated, more recently, with other prevalent conditions in diabetes, such as brain atrophy and depression. Furthermore, skin fluorescence is related to past long-term glycaemic control and clinical markers of cardiovascular disease. This review will discuss the technique of skin fluorescence, its validation as a marker of tissue AGE accumulation, and its use as a clinical tool for the prediction of long-term complications in diabetes mellitus.