Skin advanced glycation endproducts are elevated at onset of type 1 diabetes in youth

Skin Involvement in Paediatric Patients with Type 1 Diabetes

Skin involvement is an overlooked aspect in the management of paediatric patients with type 1 diabetes. A comprehensive search of published literature using the PubMed database was carried out using the following key terms: "children," "pediatric/paediatric patients," "skin," "skin disorders," "type 1 diabetes." Dermatological side effects are frequently observed among diabetic children and adolescents. Insulin-induced lipodystrophies and allergic contact dermatitis caused by insulin pumps or glycaemic sensors are the most common skin reactions in these patients. Furthermore, several diabetes-associated skin diseases such as necrobiosis lipoidica, granuloma annulare, vitiligo, and bullosis diabeticorum may already be present in paediatric patients. Paediatric diabetes specialists should pay attention to their patients' skin to recognize these disorders, identify the potential causes, and choose the most suitable treatment. Finally, the evaluation of skin concentrations of advanced glycation end-products using non-invasive diagnostic techniques may be used to assess the risk of chronic complications of diabetes as early as adolescence.

Sickle Cell Disease is Associated With Elevated Levels of Skin Advanced Glycation Endproducts

Sickle cell disease (SCD) is associated with increased oxidative stress which potentially enhances generation of advanced glycation endproducts (AGEs). We estimated skin accumulation of AGEs in SCD patients and assessed their relationship with hemolysis and nephropathy. Skin intrinsic fluorescence (SIF), an estimate of AGEs, was assessed in African American patients with and without SCD. After skin excitation with light at 375, 405, and 420 nm, raw autofluorescence was adjusted using specific intrinsic corrections. Group differences in SIF were evaluated by multiple variable regression using chronological age and sex as covariates. The relationship of SIF with reticulocyte count, serum lactate dehydrogenase, estimated glomerular filtration rate (GFR), plasma creatinine, bilirubin, and urine microalbumin was assessed. There were 48 SCD patients (29 male/19 female, age=13.4±3.6 y) and 51 controls (25 male/26 female, age=10.4±5.0 y). SIF375(1.0,0.0), SIF405(0.5,0.5), and SIF420(0.5,0.5) were significantly higher in SCD patients. There was no difference in SIF between SCD patients with and without microalbuminuria. SIF 420(0.5,0.5) was correlated with reticulocyte count (r=0.33; P=0.03). Skin AGEs as estimated by SIF were higher in children with SCD and weakly associated with 1 measure of hemolysis. Further study is needed to determine whether chronic increased deposition of AGEs is associated with development of complications of SCD.

Arm, Leg, and Foot Skin Water in Persons With Diabetes Mellitus (DM) in Relation to HbA1c Assessed by Tissue Dielectric Constant (TDC) Technology Measured at 300 MHz

BACKGROUND

DM is associated with structural skin changes. However, few studies have investigated changes in dermal water and specifically its relationship to glucose control as measured by HbA1c. Our goal was to test the hypothesis that skin water, assessed by its tissue dielectric constant (TDC), is inversely related to HbA1c.

METHODS

Water content of 3 skin sites (forearm, lower leg, and foot dorsum) of 50 persons with DM was estimated by measuring TDC at 300 MHz. TDC is the ratio of tissue dielectric constant to vacuum and depends on free and bound water in the measured volume. TDC was measured in triplicate to 4 depths, 0.5. 1.5, 2.5, and 5.0 mm to include different skin components.

RESULTS

At each site increased measurement depth showed (1) a significant decrease in absolute TDC values and (2) a significant increase in foot-to-arm TDC ratios. TDC values at forearm were shown to be greater than at either leg or foot. However, testing of these 50 patients at 3 sites and 4 skin depths did not show any significant relationship between TDC and HbA1c or fasting glucose.

CONCLUSIONS

The data indicate no relationship between TDC values, as indices for skin water, and HbA1c or fasting glucose. This implies that skin TDC values to assess skin property features and changes in persons with DM are not sensitive to recent glucose control. Furthermore, the results introduce a newly applied TDC technology useful to assess skin properties of persons with DM.

Increased skin autofluorescence of children and adolescents with type 1 diabetes despite a well-controlled HbA1c: results from a cohort study

BACKGROUND

Early identification of children and adolescents with type 1 diabetes at high risk for development of complications is important, as early intervention may prevent further deterioration. Here we investigate the applicability of assessing skin advanced glycation end products (sAGEs) by skin autofluorescence (SAF) as a potential surrogate risk marker.

METHODS

This study included a cross-sectional analysis of SAF in 77 patients with type 1 diabetes mellitus and 118 healthy controls across age categories (11-12, 13-14, 15-16, and 17-19 years old). In patients, the impact of current and historical glycated hemoglobin (HbA1c) values, age, and duration of diabetes on SAF was studied in a retrospective cohort study and analyzed with multivariable analyses.

RESULTS

SAF was significantly and similarly higher in patients when compared with controls across all age categories (P ≤0.009). For patients, age, duration of diabetes, and current and historical HbA1c were associated with SAF in univariate analysis. Multivariate analysis showed no association between HbA1c and SAF. A subgroup of patients with a HbA1c-within-target (≤7.5 %/59 mmol/mol) were observed to have high SAF.

CONCLUSION

Children and adolescents with type 1 diabetes show higher SAF than controls. The presumed correlation of high HbA1c with high SAF does not exist in all patients. Thus, use of this non-invasive measure may provide a surrogate marker for diabetic complications, additional to HbA1c.

Advanced glycation end products, measured in skin, vs. HbA1c in children with type 1 diabetes mellitus

BACKGROUND AND OBJECTIVE

Advanced glycation end products (AGEs) are considered major contributors to microvascular and macrovascular complications in adult patients with diabetes mellitus. AGEs can be measured non-invasively with skin autofluorescence (sAF). The primary aim was to determine sAF values in children with type 1 diabetes mellitus and to study correlations between sAF values and HbA1c and mean HbA1c over the year prior to measurement

RESEARCH DESIGN AND METHODS

In children with type 1 diabetes mellitus, sAF values were measured using the AGE Reader®. Laboratory and anthropometric values were extracted from medical charts. Correlations were studied using Pearson's correlation coefficient. Multivariable linear regression analysis was conducted to evaluate the effect of multiple study parameters on sAF values.

RESULTS

The mean sAF value was 1.33 ± 0.36 arbitrary units (AU) in children with type 1 diabetes mellitus (n = 144). sAF values correlated positively with HbA1c measured at the same time (r = 0.485; p < 0.001), mean HbA1c over the year prior to measurement (r = 0.578; p < 0.001), age (r = 0.337; p < 0.001), duration of type 1 diabetes mellitus (r = 0.277; p = 0.001), serum triglycerides (r = 0.399; p < 0.001), and total cholesterol (r = 0.352; p = 0.001). sAF values were significantly higher in patients with non-white skin (1.56 vs. 1.27 AU, respectively, p = 0.001).

CONCLUSIONS

In children with type 1 diabetes, sAF values correlate strongly with single HbA1c and mean HbA1c, making the non-invasive sAF measurement an interesting alternative to provide information about cumulative hyperglycemic states. To determine the value of sAF measurement in predicting long-term microvascular and macrovascular complications, further prospective follow-up studies are needed.

Early Formation of Serum Advanced Glycation End-Products in Children with Type 1 Diabetes Mellitus: Relationship with Glycemic Control

OBJECTIVES

To quantify serum advanced glycation end-products (AGEs) at the onset of type 1 diabetes mellitus and to determine their potential usefulness as retrospective indicators of glycemic balance.

STUDY DESIGN

Carboxymethyllysine (CML) and pentosidine concentrations were determined by liquid chromatography-tandem mass spectrometry in 3 groups of children with type 1 diabetes mellitus: group (Gr) 1, subjects included at disease onset (n = 36); Gr2, subjects with diabetes of 5 years duration (n = 48); Gr3, subjects with diabetes of 10 years duration and in control subjects (n = 33). Hemoglobin A1c (HbA1c) values were recorded over the entire course of treatment for assessing long-term glycemic balance.

RESULTS

Serum AGE concentrations were increased in all groups of subjects with diabetes compared with control subjects, but were highest in Gr1 (for CML: 0.155, 0.306, 0.219, and 0.224 mmol/mol Lys in control, Gr1, Gr2, and Gr3 subjects, respectively; for pentosidine: 312, 492, 365, and 403 nmol/mol Lys, respectively). AGE concentrations were closely correlated with HbA1c values (r = 0.78 for CML; r = 0.49 for pentosidine). In Gr2 and Gr3, the overall glycemic balance estimated by average HbA1c values was positively correlated with CML and pentosidine concentrations, especially in the first year of follow-up.

CONCLUSION

Our results indicate that AGE concentrations are elevated in serum at the time of diabetes mellitus diagnosis, suggesting that the deleterious role of AGEs in the development of long-term complications should be taken into account even at the initial stages of the disease. Moreover, in some circumstances, AGEs could serve as surrogate markers of HbA1c for monitoring glycemic control.