Endothelial dysfunction in children with type 1 diabetes mellitus

The Relationship between Selected Inflammation and Oxidative Stress Biomarkers and Carotid Intima-Media Thickness (IMT) Value in Youth with Type 1 Diabetes Co-Existing with Early Microvascular Complications

Recent years have confirmed the importance of oxidative stress and biomarkers of inflammation in estimating the risk of cardiovascular disease (CVD) and explaining not fully understood pathogenesis of diabetic macroangiopathy. We aimed to analyze the relation between the intima-media thickness (IMT) of common carotid arteries and the occurrence of classical cardiovascular risk factors, together with the newly proposed biomarkers of CVD risk (high-sensitivity C-reactive protein (hsCRP), myeloperoxidase (MPO), adiponectin, N-terminal-pro B-type natriuretic peptide (NT-proBNP) and vitamin D) in youth with type 1 diabetes (T1D) recognized in screening tests to present early stages of microvascular complications (VC). The study group consisted of 50 adolescents and young adults with T1D, mean age 17.1 years (10–26 age range), including 20 patients with VC (+) and 30 VC (−). The control group (Control) consisted of 22 healthy volunteers, mean age 16.5 years (11–26 age range). In the VC (+) patients, we found a significantly higher concentration of HbA1c, lipid levels, hsCRP and NT-proBNP. BMI and blood pressure values were highest in the VC (+) group. Higher levels of MPO and lower levels of vitamin D were found in both diabetic groups vs. Control. IMT in VC (+) patients was significantly higher and correlated positively with HbA1c, hsCRP, NT-pro-BNP and negatively with vitamin D levels. In conclusion, youth with T1D and VC (+) present many abnormalities in the classical and new CVD biomarkers. hsCRP and MPO seem to be the most important markers for estimating the risk of macroangiopathy. NT-proBNP may present a possible marker of early myocardial injury in this population.

Endothelial Dysfunction in the Context of Blood–Brain Barrier Modeling

Here, we discuss pathophysiological approaches to the defining of endothelial dysfunction criteria (i.e., endothelial activation, impaired endothelial mechanotransduction, endothelial-to-mesenchymal transition, reduced nitric oxide release, compromised endothelial integrity, and loss of anti-thrombogenic properties) in different in vitro and in vivo models. The canonical definition of endothelial dysfunction includes insufficient production of vasodilators, pro-thrombotic and pro-inflammatory activation of endothelial cells, and pathologically increased endothelial permeability. Among the clinical consequences of endothelial dysfunction are arterial hypertension, macro- and microangiopathy, and microalbuminuria. We propose to extend the definition of endothelial dysfunction by adding altered endothelial mechanotransduction and endothelial-to-mesenchymal transition to its criteria. Albeit interleukin-6, interleukin-8, and MCP-1/CCL2 dictate the pathogenic paracrine effects of dysfunctional endothelial cells and are therefore reliable endothelial dysfunction biomarkers in vitro, they are non-specific for endothelial cells and cannot be used for the diagnostics of endothelial dysfunction in vivo. Conceptual improvements in the existing methods to model endothelial dysfunction, specifically, in relation to the blood–brain barrier, include endothelial cell culturing under pulsatile flow, collagen IV coating of flow chambers, and endothelial lysate collection from the blood vessels of laboratory animals in situ for the subsequent gene and protein expression profiling. Combined with the simulation of paracrine effects by using conditioned medium from dysfunctional endothelial cells, these flow-sensitive models have a high physiological relevance, bringing the experimental conditions to the physiological scenario.

Impact of the nature of the capillary wall on plasma refilling during hemodialysis

OBJECTIVES

Our aim was to clarify the impact of the nature of the capillary wall, defined by the contribution of large (LP), small (SP), and ultrasmall (UP) pores, on plasma refilling in a hemodialysis session.

METHODS

This study included data from 78 patients. The relative blood volume change (ΔBV%) was monitored using a Crit-Line monitor. A bioimpedance device was used to measure extracellular and intracellular fluid volumes, and the excess fluid mass (M_ExF) was calculated. We simulated blood volume change (sΔBV%) based on a three-pore model. Hydraulic permeability of the capillary wall (LpS) and fractional contribution of LP to LpS (α_LP) were determined by fitting sΔBV to ΔBV. The total refilling volume (TV_ref) was calculated from the total ultrafiltration volume and total blood volume change. Values were standardized to a body surface area of 1.73 m² and are denoted by the subscript BSA.

RESULTS

LpS and α_LP were 3.09 (2.32, 4.68) mL/mmHg/min and 0.069 (0.023, 0.109), respectively. The standardized regression coefficient (β) of the ultrafiltration rate (UFR_BSA) and initial excess fluid mass (M_ExF,_BSA,0) by multiple linear regression analysis of TV_ref,BSA without (Model 1) and with (Model 2) α_LP were as follows: UFR_BSA, 0.714/<0.001 (β/p); M_ExF,_BSA,0, 0.247/<0.001 (Model 1); UFR_BSA, 0.799/<0.001; M_ExF,_BSA,0, 0.066/0.237; and α_LP, -0.327/<0.001 (Model 2).

CONCLUSIONS

The impact of volume overload (M_ExF,_BSA,0) on plasma refilling became insignificant with the addition of α_LP in the model, suggesting that the nature of the capillary wall described by inter-endothelial gaps (LP) may have a greater impact on plasma refilling than volume overload.

The relation of serum endocan and soluble endoglin levels with metabolic control in children and adolescents with type 1 diabetes mellitus

Objectives Endothelial dysfunction is an early marker of vascular disease in Type 1 diabetes mellitus (T1DM). In the present study, we aimed to investigate serum endocan and soluble endoglin (S-endoglin) levels, and their relation with metabolic control in children with T1DM, which was not previously assessed. Methods A total of 64 T1DM subjects and 64 healthy subjects were included in this study. Their anthropometric features, arterial blood pressures, pubertal status, insulin doses were recorded. Glycated hemoglobin, serum endocan and S-endoglin levels were measured and compared to each other. Results Serum endocan and S-endoglin levels were higher in children with T1DM than those of healthy group (p<0.01). Significant positive correlation was detected between both endocan and S-endoglin (r=0.579, p<0.001); and HbA1c and endocan (r=0.296, p=0.01). Compared to patients with good metabolic control, those with poorer metabolic control (HbA1c > 8%) had an older age, longer duration of diabetes, higher number of pubertal children. Also, patients with poorer metabolic control had higher endocan and S-endoglin levels than those of healthy group, but this finding did not reach statistical significance. There was no correlation between the endocan/S-endoglin levels and age, duration of diabetes and insulin dose. Conclusion Serum levels of endocan and S-endoglin which are novel biomarkers of endothelial dysfunction are high in children with T1DM. Elevated serum endocan and endoglin levels in children with T1DM without microvascular complications indicates endothelial damage in very early stages of the disease.

Preclinical arterial disease in patients with type 1 diabetes without other major cardiovascular risk factors or micro-/ macrovascular disease

We aimed to investigate preclinical atherosclerosis in T1D and its relationship with glucose profile and endothelial/ inflammatory markers. Thirty-eight T1D patients without additional cardiovascular risk factors or micro-/macrovascular complications and 22 healthy matched subjects were included. FMD and cIMT/fIMT were performed in addition to 72-h continuous glucose monitoring and the measurement of endothelial/inflammatory markers. Lower FMD percentages and greater cIMT/fIMT were observed in patients with T1D in comparison with controls (FMD 7.0 ± 3.1% vs. 9.6 ± 2.2%; p<0.005; cIMT 0.523 ± 0.091 mm vs. 0.471 ± 0.061 mm; p<0.05 and fIMT 0.512 ± 0.172 mm vs. 0.394 ± 0.061 mm; p<0.01, for patients and controls, respectively). T1D subjects in the highest tertile of cIMT were older than those in the lowest group (39.9 ± 9.5 vs. 29.6 ± 4.7 years; p<0.005) and had a longer duration of the disease (18.7 ± 5.4 years vs. 11.8 ± 6.4 years). The higher the cIMT tertile, the greater the fIMT (0.397 ± 0.114 mm vs. 0.431 ± 0.082 mm vs. 0.583 ± 0.197 mm; p<0.05). MAGE was negatively correlated to FMD (r=-0.328; p<0.05) and positively to cIMT (r=0.322; p<0.05). There were no differences between cIMT tertiles in terms of metabolic parameters or endothelial and inflammatory markers. Signals of preclinical atherosclerosis in T1D even in the absence of cardiovascular risk factors and micro- / macrovascular disease are reported. Our findings suggest that daily glucose instability could negatively impact vascular function and structure.

[Endothelial dysfunction in type 1 diabetes]

Vascular complications are the main cause of mortality and morbidity in diabetes. Mechanisms involved in the development of micro and macrovascular disease are complex and partially understood, but invariably begin as a dysfunctional endothelium. Nitric oxide is an important regulator of endothelial function and the impairment of its activity is determinant of the endothelial dysfunction. In type 1 diabetes, many factors like acute, chronic and post-prandial hyperglycemia, as well as the duration of diabetes or autonomic neuropathy and microalbuminuria are associated to endothelial dysfunction. Oxidative stress, polyol pathway activation, protein kinase C activation and the presence of advanced glycation end-products are potential mechanisms involved in the development of endothelial dysfunction. Early detection of endothelial dysfunction has prognostic value for the development of vascular complications and may be important in strategies for primary prevention of cardiovascular endpoints in type 1 diabetes.

Autoimmune-mediated oxidative stress and endothelial dysfunction: implications of accelerated vascular injury in type I diabetes

The pathogenesis of cardiovascular disease in the setting of type 1 diabetes is not well-defined. The hypothesis that hyperglycemia is largely responsible for vascular endothelial dysfunction, and ultimately atherosclerosis, continues to evolve. However, despite tight glucose control, a subset of patients still develop clinically significant occlusive disease. While the specific mechanisms of persistent vascular injury are not clear, an increasing body of evidence suggests a dysregulated autoimmune response may contribute to the development of vascular injury. That is, the same inflammatory response that is responsible for pancreatic beta-cell destruction may facilitate chronic vascular endothelial injury prior to the onset of hyperglycemia. Herein, we discuss (1) the clinical experience with tight glycemic control and the risk of cardiovascular disease in patients with type 1 diabetes; (2) the cellular mechanisms involved in vascular endothelial injury; and (3) the long-term clinical implications of autoimmune-mediated vascular disease and current treatment strategies.

Altered endothelial function in asymptomatic male adolescents with type 1 diabetes

OBJECTIVE

While adult men and women with diabetes experience similar rates of cardiovascular disease, early microvascular complications show significant gender differences during adolescence. The goal of this study was to determine whether a gender contrast in a preclinical stage of atherosclerosis, or endothelial dysfunction, is present in pediatric diabetic patients.

METHODS

Reactive hyperemia-peripheral arterial tonometry (RH-PAT), a noninvasive method to assess endothelial dysfunction, was used. Measurements were performed at rest and after hyperemia in 20 diabetic subjects and 20 age- and gender-matched nondiabetics, aged 12-16 years. Confounding risk factors for endothelial dysfunction, including smoking, obesity, and hypertension, were excluded.

RESULTS

RH-PAT was lower for male diabetic subjects vs. controls (n = 12, 1.60 +/- 0.32 vs. 1.92 +/- 0.28, P < .001). RH-PAT was similar in female diabetic patients vs. controls. Male and females with type 1 diabetes subjects had equivalent metabolic control (HbA1C 7.48 +/- 1.0 vs. 7.51 +/- 0.9) and lipid profiles. No difference was observed in age, HbA1C, and diabetes duration, between male and female diabetic subjects. However, diabetic female patients had a greater body mass index (24.2 +/- 2.5 vs. 20.6 +/- 2.0, P = .003) and were more mature in pubertal status as compared with diabetic male patients.

CONCLUSION

Endothelial dysfunction was present in adolescent male diabetic subjects as measured using RH-PAT. Considering that endothelial dysfunction is reversible, early detection of this process may have therapeutic and prognostic implications in this young age group.

Alterations of von Willebrand Factor and Ristocetin Cofactor Activity During Atrial Fibrillation

The aim of this study was to assess the plasma levels of von Willebrand factor antigen and ristocetin cofactor activity, which are well-known markers of endothelial function, in atrial fibrillation (AF) with or without mitral stenosis (MS). Forty-two patients (16 patients with MS and AF [MS(+)AF(+)], 13 patients with nonvalvular AF [MS(−)AF(+)], and 13 patients with MS and sinus rhythm [MS(+)AF(−)]) were included. Von Willebrand factor antigen levels and ristocetin cofactor activities in all participants were assessed. Overall, von Willebrand factor antigen levels and ristocetin cofactor activities in the AF(+) patients were higher than in the AF(−) patients ( P = .003 and P = .002, respectively). Von Willebrand factor antigen levels and ristocetin cofactor activities in the 3 groups were found to be different ( P = .012 and P = .01, respectively). Von Willebrand factor antigen levels were similar between the MS(+)AF(+) and MS(−)AF(+) groups and were higher than that of the MS(+)AF(−) group. Ristocetin cofactor activity in the MS(−)AF(+) group was significantly higher than in the other 2 groups. The ristocetin cofactor activity and von Willebrand factor antigen levels were significantly higher in diabetic or hypertensive patients than in nondiabetic or normotensive patients. According to the results of this study, circulating von Willebrand factor antigen levels and plasma ristocetin cofactor activities are affected by the presence of AF, MS, and associated comorbidities including type 2 diabetes mellitus and systemic hypertension. Further studies are needed to assess the role of von Willebrand factor antigen and ristocetin cofactor activity in predicting vascular thrombotic events in AF, MS, systemic hypertension, and diabetes mellitus.

Insulin therapy in the pediatric intensive care unit

BACKGROUND & AIMS

Hyperglycemia is a major risk factor for increased morbidity and mortality in the intensive care unit. Insulin therapy has emerged in adult intensive care units and several pediatric studies are currently being conducted. This review discusses hyperglycemia and the effects of insulin on metabolic and non-metabolic pathways, with a focus on pediatric critical illness.

METHODS

A PubMed search was performed by using the following keywords and limits (("hyperglycemia"[MeSH terms] or ("insulin resistance"[MeSH major topic]) and ("critical care"[MeSH terms] or "critical illness"[MeSH terms])) in different combinations with ("metabolism"[MeSH terms] or "metabolic networks and pathways"[MeSH terms]) and ("outcome"[all fields]) and ("infant"[MeSH terms] or "child"[MeSH terms] or "adolescent"[MeSH terms]). Quality assessment of selected studies included clinical pertinence, publication in peer-reviewed journals, objectivity of measurements and techniques used to minimize bias. Reference lists of such studies were included.

RESULTS

The magnitude and duration of hyperglycemia are associated with increased morbidity and mortality in the pediatric intensive care unit (PICU), but prospective, randomized controlled studies with insulin therapy have not been published yet. Evidence concerning the mechanism and the effect of insulin on glucose and lipid metabolism in pediatric critical illness is scarce. More is known about the positive effect on protein homeostasis, especially in severely burned children. The effect in septic children is less clear and seems age dependent. Some non-metabolic properties of insulin such as the modulation of inflammation, endothelial dysfunction and coagulopathy have not been fully investigated in children.

CONCLUSION

Future studies on the effect of insulin on morbidity and mortality as well as on the mechanisms through which insulin exerts these effects are necessary in critically ill children. We propose these studies to be conducted under standardized conditions including precise definitions of hyperglycemia and rates of glucose intake.

Oxidant stress, immune dysregulation, and vascular function in type I diabetes

Although high glucose is an important contributor to diabetic vasculopathies, complications still occur in spite of tight glycemic control, suggesting that some critical event prior to or concurrent with hyperglycemia may contribute to early vascular changes. Utilizing previously published and new experimental evidence, this review will discuss how prior to the hyperglycemic state, an imbalance between oxidants and antioxidants may contribute to early vascular dysfunction and set in motion proinflammatory insults that are further amplified as the diabetes develops. This imbalance results from the resetting of the equilibrium between vessel superoxide/H(2)O(2) production and/or decreased antioxidant defenses. Such an imbalance may cause endothelial dysfunction, characterized by abnormal endothelium-dependent vasoreactivity, as the first sign of blood vessel damage, followed by morphological changes of the vessel wall and inflammation. As such, increased oxidant stress in preglycemic states may be a critically central initiating event that underlies the pathogenesis of life-threatening vascular diseases in autoimmune diabetes. This review focuses on the relationship between oxidative stress, immune dysregulation, and vascular injury in type 1 diabetes, and how the discovery of novel pathways of vascular disease in nonobese diabetic mice may direct future studies in patients with type 1 diabetes.

Obesity, metabolic syndrome, and cardiovascular disease

Early childhood overweight and obesity have alarmingly increased over the years. Adulthood obesity is a well demonstrated significant independent predictor of cardiovascular risk (CVR) and/or mortality, which predisposes to the major components of metabolic syndrome (MS). Evidence of MS in obese children has been also reported associated with biochemical and inflammatory factors that affect vascular physiologic function. Assessment of vascular function can be measured noninvasively in children allowing early detection of endothelial dysfunction and severe increase of arterial stiffness before clinical manifestations of atherosclerosis. Impairment of endothelial function related to the severity of obesity and to the degree of insulin resistance is considered as a condition that confers a premature atherogenicity status and is linked to adult conventional cardiovascular risk factors. Adipose tissue factors that interfere with insulin action and endothelial cell function have also been identified as major precursors of CVR factors. The metabolic and cardiovascular consequences of childhood obesity are well demonstrated and have a major impact on the development of atherosclerosis and lifetime CVR. The development of programs involving both diet and exercise for children with overt overweight/obesity appears to be essential to improve vascular function and metabolic disorders. Such interventions should be complemented by a primary prevention against childhood obesity.

Matrix metalloproteinase 2 may be a marker of microangiopathy in children and adolescents with type 1 diabetes mellitus

Matrix metalloproteinases (MMPs) 2 and 9 are responsible for extracellular matrix breakdown and their abnormal circulating levels may pre-date clinical evidence of diabetic angiopathy. We detected by ELISA, plasma MMP-2 and MMP-9 levels and associated activity in 25 children and adolescents with T1DM. Thirteen male and 12 female patients were evaluated at the clinical diagnosis and onset of T1DM and again at a 5-year follow-up. Twelve patients had developed microangiopathic complications at the follow-up evaluation. MMP-2 and MMP-9 levels and activity were detected in samples obtained at T1DM diagnosis and at the 5-year follow-up. As controls, 19 healthy subjects who were the same age as the patients were also evaluated at baseline and again after 5 years. MMP-2 levels and activity were significantly higher in the patients than in the controls at disease onset. This was particularly evident when patients who developed microangiopathic complications were compared to controls and patients without complications. At the 5-year follow-up, a significant increase in MMP-2 levels and a significant decrease in MMP-2 activity were found only in the control group compared to the baseline levels. MMP-2 levels and activity were higher in patients with microangiopathy. MMP-9 levels and activity were increased in all groups compared to baseline levels. MMP-9 levels were lower in patients with microangiopathy compared to controls, but no difference was found between the two patient groups. It is well known that MMP-9 is an index of the severity and stability of macroangiopathy while our results allow us to postulate that MMP-2 may be a marker of microangiopathy.

Noninvasive assessment of arterial stiffness and risk of atherosclerotic events in children

Noninvasive assessment of vascular dysfunction in the pediatric population has taken advantage of the development of high-resolution ultrasound techniques. The most frequently used methods are the quantification of flow-mediated endothelium-dependent dilation of the brachial artery and measurement of the intima-media thickening of the carotid artery. Both reduced flow-mediated dilation and increased intima-media thickness have been proven to correlate with late cardiovascular events and/or mortality in adults. As these noninvasive methods can easily be applied in children, there have been recent investigations in high-risk pediatric patients harboring classical cardiovascular risk factors. Endothelial dysfunction and increased thickness of the intima media are currently observed in children with familial hypercholesterolemia, obesity, and type 1 diabetes mellitus. The association of early vascular dysfunction with a known risk factor is an important issue as these anomalies precede the formation of atherosclerotic plaques. Therefore, they may help in stratification of the risk for cardiovascular event and to better tailor therapeutic interventions in at risk children. Finally, these methods have been applied in specific pediatric populations, such as children with end-stage renal disease, chronic parenteral nutrition, HIV infection, and coarctation of the aorta. In these conditions, endothelial dysfunction and vascular remodeling are also present early in life and these data raise new possibilities in the understanding of the pathogenesis of atherosclerosis in these populations.

Parameters for Measurement of Oxidative Stress in Diabetes Mellitus: Applicability of Enzyme-Linked Immunosorbent Assay for Clinical Evaluation

Investigations of the mechanisms involved in the onset and progression of diabetes have recently confronted the role of reactive oxygen species (ROS) and oxidative stress. Prolonged exposure to hyperglycemic conditions induces nonenzymatic glycation of protein via the so-called Maillard reaction, resulting in Schiff-base products and Amadori products that engender ROS production. These processes initiate and exacerbate micro- and macrovascular complications in diabetes. Increased oxidative stress is induced by excessive ROS production and inadequate antioxidant defenses. Recently, oxidative stress status markers have been associated directly with the severity and prognosis of diabetes. To examine oxidative stress, reliable and high-throughput methods are needed to examine large numbers of clinical samples. The emerging availability of enzyme-linked immunosorbent assay (ELISA) for oxidative stress status markers allows its application to assessment of various pathophysiologic conditions, including diabetes. This review outlines the recent achievements of ELISA application for clinical studies elucidating oxidative stress. It introduces the potential applicability of ELISA for investigating oxidative stress in diabetes.

Endothelial Dysfunction in Patients With Chronic Periodontitis and Its Improvement After Initial Periodontal Therapy

BACKGROUND

Recent epidemiological data suggested that there is a relationship between periodontal health and atherosclerotic coronary heart disease. Although hypothetical models were proposed, the exact mechanism of this association has not been clarified. The aim of this study is to investigate whether there is an endothelial dysfunction in patients with chronic periodontitis and, if present, whether recovery is possible with therapy.

METHODS

The study groups consisted of 28 patients (mean age: 45.5 +/- 8.6 years) with chronic periodontitis and without any atherosclerotic vascular disease, and 26 healthy controls (mean age: 43.7 +/- 6.8 years). Cardiovascular risk factors were investigated in both groups. Brachial artery responses to reactive hyperemia (endothelium-dependent dilatation [EDD]) and sublingual nitroglycerin (endothelium-independent dilatation [EID]) were measured using high-resolution vascular ultrasound in both groups. Measurements were taken before and after initial periodontal therapy in the periodontal patients.

RESULTS

There was no significant difference between the groups with regard to cardiovascular risk factors. In the baseline measurements, EDD and EID were significantly impaired in patients with chronic periodontitis when compared with the controls (8.4% +/- 4.0% versus 19.4% +/- 8.1%, P<0.0001; 13.3% +/- 6.3% versus 29.5% +/- 10.0%, P<0.0001 for EDD and EID, respectively). After non-surgical periodontal therapy, EDD and EID improved significantly (from 8.4% +/- 4.0% to 17.7% +/- 5.7%, P<0.0001; and from 13.3% +/- 6.3% to 24.9% +/- 7.3%, P<0.0001 for FMD and EID, respectively). The EDD and EID changes in the controls were insignificant.

CONCLUSION

This study showed that endothelial functions were impaired in patients with chronic periodontitis and that they improve following initial periodontal therapy.

Formation of advanced glycosylation end products and oxidative stress in young patients with type 1 diabetes

Increased production of advanced glycosylation end products (AGEs) and augmented oxidative stress may contribute to vascular complications in diabetes. Little is known about the formation and accumulation of AGEs in young patients with type 1 diabetes. The aim of the present study was to investigate whether AGE production and oxidative stress are augmented in young patients with type 1 diabetes at early clinical stages of the disease. Urine samples of 38 patients with type 1 diabetes [mean age (+/-SD), 12.8 +/- 4.5 y; diabetes duration, 5.7 +/- 4.3 y; HbA1c, 8.0 +/- 1.6%; urinary albumin excretion, 12.6 +/- 14.4 mg/g creatinine (Cr)] and those of 60 age-matched healthy control subjects were assayed for AGEs, pentosidine and pyrraline, and markers of oxidative stress, 8-hydroxy-2'-deoxyguanosine (8-OHdG) and acrolein-lysine. Of these four markers, urinary concentrations of pentosidine, 8-OHdG, and acrolein-lysine were significantly higher in the patients with diabetes than in the healthy control subjects. For the patient group, pentosidine correlated significantly with 8-OHdG and acrolein-lysine, and pyrraline correlated significantly with acrolein-lysine. Urinary pentosidine, 8-OHdG, and acrolein-lysine but not pyrraline correlated significantly with urinary albumin excretion. Patients with microalbuminuria (> or =15 mg/g Cr) showed significantly higher levels of all four markers than did normoalbuminuric patients and control subjects. The present study indicates that accumulation of AGEs, whose formation is closely linked to oxidative stress, and resultant endothelial dysfunction may start early in the course of type 1 diabetes. This means that the risk of vascular complications may be present at an early age and that the best possible glycemic control should be emphasized from the diagnosis of diabetes.

Type 2 diabetes mellitus in adolescence: lipid and cardiovascular risk factors

This review discusses the important consequences of dyslipidemia and arteriosclerosis in type 2 diabetes as documented in studies in adults. It then examines the relatively recent upsurge in type 2 diabetes in children and adolescents, its characteristics, and its importance in directing our attention to cardiovascular risk factors in this age group. The discussion concludes with an examination of the information available about arteriosclerosis in the young and about the treatment of hypercholesterolemia in children and adolescents.