For diabetic type 1 patients, the skin autofluorescence predicts ulcers and amputations

The skin autofluorescence of advanced glycation end-products relates to the development of foot ulcers in type 2 diabetes: A longitudinal observational study

OBJECTIVES

The long-term glycemic memory contributes to vascular complications in type 2 diabetes, including those patients with Diabetic Foot Ulcers (DFU). We investigated whether the skin autofluorescence (SAF) of Advanced Glycation End-products related to later DFUs.

RESEARCH DESIGN & METHODS

SAF was measured with an AGE-Reader in a retrospective cohort of patients hospitalized from 2009 to 2017 for Type 2 Diabetes. New DFUs were registered until the year 2020 and survival analyses were performed.

RESULTS

The 517 patients (men: 58.0 %), were 62 ± 9 years old at baseline, with a duration of diabetes of 14 ± 10 years, HbA1c: 8.7 ± 1.8 %, complications included 33.8 % macroangiopathies, 44.9 % diabetic kidney diseases and 26.7 % retinopathies. According to the IWGDF classification, the grades of risk for DFU were 0 for 43.2 %, 1 for 23.9 %, 2 for 7.2 %, and 3 for 25.7 %. During the 53 months of follow-up, 58 new DFUs occurred, mostly in patients with SAF higher than its median value (2.65 AU). Adjusted for age and sex, conventional risk factors (duration and control of diabetes, arterial hypertension, dyslipidemia, smoking), and other complications (macroangiopathy, diabetic kidney disease, retinopathy), SAF related to later DFUs. Adjusted for the IWGDF classification, SAF related to new DFUs (HR: 1.81, 95%CI:1.25-2.62). This relationship was significant for the 403 subjects without previous history of DFU (HR: 2.32, 95%CI: 1.36-3.95). SAF did not predict recurrence for patients with a previous history of DFUs.

CONCLUSION

SAF, a simple non-invasive marker of glycemic memory, independently predicts the occurrence of a first foot ulcer in patients with Type 2 Diabetes.

Cutaneous changes in diabetic patients: Primed for aberrant healing?

Cutaneous manifestations affect most patients with diabetes mellitus, clinically presenting with numerous dermatologic diseases from xerosis to diabetic foot ulcers (DFUs). Skin conditions not only impose a significantly impaired quality of life on individuals with diabetes but also predispose patients to further complications. Knowledge of cutaneous biology and the wound healing process under diabetic conditions is largely limited to animal models, and studies focusing on biology of the human condition of DFUs remain limited. In this review, we discuss the critical molecular, cellular, and structural changes to the skin in the hyperglycaemic and insulin-resistant environment of diabetes with a focus specifically on human-derived data. Elucidating the breadth of the cutaneous manifestations coupled with effective diabetes management is important for improving patient quality of life and averting future complications including wound healing disorders.

Diabetic Peripheral Neuropathy Associated with Foot Ulcer: One of a Kind

Significance: Diabetic peripheral neuropathy (DPN) associated with a diabetic foot ulcer (DFU) is likely to be complicated with critical factors such as biofilm infection and compromised skin barrier function of the diabetic skin. Repaired skin with a history of biofilm infection is known to be compromised in barrier function. Loss of barrier function is also observed in the oxidative stress affected diabetic and aged skin. Recent Advances: Loss of barrier function makes the skin prone to biofilm infection and cellulitis, which contributes to chronic inflammation and vasculopathy. Hyperglycemia favors biofilm formation as glucose lowering led to reduction in biofilm development. While vasculopathy limits oxygen supply, the O2 cost of inflammation is high increasing hypoxia severity. Critical Issues: The host nervous system can be inhabited by bacteria. Because electrical impulses are a part of microbial physiology, polymicrobial colonization of the host's neural circuit is likely to influence transmission of action potential. The identification of perineural apatite in diabetic patients with peripheral neuropathy suggests bacterial involvement. DPN starts in both feet at the same time. Future Directions: Pair-matched studies of DPN in the foot affected with DFU (i.e., DFU-DPN) compared with DPN in the without ulcer, and intact skin barrier function, are likely to provide critical insight that would help inform effective care strategies. This review characterizes DFU-DPN from a translational science point of view presenting a new paradigm that recognizes the current literature in the context of factors that are unique to DFU-DPN.

Skin autofluorescence as tool for cardiovascular and diabetes risk prediction

PURPOSE OF REVIEW

Advanced glycation endproducts (AGE) have an important role in the development of chronic complications in diabetes mellitus and in renal failure. Skin autofluorescence (SAF) is a simple noninvasive optical technique to estimate AGE levels in the dermis. SAF increases with age, but rises more rapidly in diabetes and renal failure, and is also associated with, and a predictor of their complications.

RECENT FINDINGS

In recent large population studies, SAF is a strong predictor of development of type 2 diabetes (T2D), and in persons with known diabetes of its complications. SAF also predicts new cardiovascular disease (CVD) and mortality not only in individuals with known type 2 diabetes but also in the general population.

SUMMARY

SAF is a simple, powerful and independent predictor for development of type 2 diabetes (T2D), and also for cardiovascular disease and mortality in both persons with diabetes, and in the general population.

Skin autofluorescence corresponds to microvascular reactivity in diabetes mellitus

Advanced glycation accelerated by chronic hyperglycaemia contributes to the development of diabetic vascular complications throughout several mechanisms. One of these mechanisms is supposed to be impaired microvascular reactivity, that precedes significant vascular changes. The aim of this study was to find an association between advanced glycation, the soluble receptor for AGEs (sRAGE), and microvascular reactivity (MVR) in diabetes. Skin autofluorescence (SAF), which reflects advanced glycation, was assessed by AGE-Reader, MVR was measured by laser Doppler fluxmetry and evaluated together with sRAGE in 43 patients with diabetes (25 Type 1 and 18 Type 2) and 26 healthy controls of comparable age. SAF was significantly higher in patients with diabetes compared to controls (2.4 ± 0.5 vs. 2.0 ± 0.5 AU; p < 0.01). Patients with diabetes with SAF > 2.3 AU presented significantly worse MVR in both post-occlusive reactive hyperaemia (PORH) on the finger and forearm, and thermal hyperaemia (TH), compared to patients with SAF < 2.3 AU. SAF was age dependent in both diabetes (r = 0.41, p < 0.01) and controls (r = 0.45, p < 0.05). There was no association between SAF and diabetes control expressed by glycated haemoglobin. A significant relationship was observed between SAF and sRAGE in diabetes (r = 0.56, p < 0.001), but not in controls. A significant inverse association was found between SAF and MVR on the forearm in diabetes (PORH: r = -0.42, p < 0.01; TH: r = -0.46, p < 0.005). Both advanced glycation expressed by higher SAF or sRAGE and impaired MVR are involved in the pathogenesis of vascular complications in diabetes, and we confirm a strong interplay of these processes in this scenario.