Relation of serum leptin and insulin-like growth factor-1 levels to intima-media thickness and functions of common carotid artery in children and adolescents with type 1 diabetes

Serum adipokine levels in patients with type 1 diabetes are associated with degree of obesity but only resistin is independently associated with atherosclerosis markers

PURPOSE

The role of adipokines in causing inflammation and insulin resistance in normal weight and obese patients is generally well studied. However, there are often conflicting results regarding their levels in type 1 diabetes mellitus (T1DM) patients and their relationship to micro- and macrovascular disease. We therefore investigated which serum adipokine levels are independently associated with markers of early atherosclerosis and microvascular complications in patients with T1DM.

METHODS

A cross-sectional study was performed in the Diabetes Outpatient Clinic of Hippokrateion General Hospital, Thessaloniki, Greece. Sixty T1DM patients (30 females, mean age 38.8 ± 10.6 years, mean diabetes duration 17.4 ± 9.9 years) were included. Plasma adiponectin, leptin, and resistin, carotid artery intima media thickness (cIMT), and arterial stiffness (pulse wave velocity, PWV/SpygmoCor CP System and Mobil-O-Graph 24 h PWA) were assessed.

RESULTS

Leptin and resistin levels were significantly higher in overweight and obese patients (p = 0.002 and p = 0.039, respectively). Adiponectin was the only adipokine negatively correlated with BMI (r_s =  - 0.41, p = 0.001). We report a bivariate association between serum adiponectin levels and retinopathy (p = 0.007). Resistin was the only adipokine that showed significant correlation with systolic (r_s = 0.42, p = 0.001) and diastolic (r_s = 0.29, p = 0.024) hypertension and PWV (p = 0.035).

CONCLUSIONS

Serum adipokine levels demonstrate similar bivariate associations with anthropometric variables in patients with T1DM to those in normal weight subjects. Although microvascular complications are associated with serum adipokine levels by bivariate analysis, only resistin, an inflammatory marker, is independently associated with arterial stiffness in patients with T1DM.

Obesity-Induced Changes in Adipose Tissue Microenvironment and Their Impact on Cardiovascular Disease

Obesity is causally linked with the development of cardiovascular disorders. Accumulating evidence indicates that cardiovascular disease is the collateral damage of obesity-driven adipose tissue dysfunction that promotes a chronic inflammatory state within the organism. Adipose tissues secrete bioactive substances, referred to as adipokines, which largely function as modulators of inflammation. The microenvironment of adipose tissue will affect the adipokine secretome, having actions on remote tissues. Obesity typically leads to the upregulation of proinflammatory adipokines and the downregulation of anti-inflammatory adipokines, thereby contributing to the pathogenesis of cardiovascular diseases. In this review, we focus on the microenvironment of adipose tissue and how it influences cardiovascular disorders, including atherosclerosis and ischemic heart diseases, through the systemic actions of adipokines.

Residual β-cell function and the insulin-like growth factor system in Danish children and adolescents with type 1 diabetes

CONTEXT

C-peptide-positive adults with type 1 diabetes (T1D) have higher circulating total and free IGF-1 and lower IGF binding protein 1 (IGFBP-1) than C-peptide-negative patients. Whether this is also the case in children remains unknown.

OBJECTIVE

The objective of the study was to examine the IGF system in children/adolescents with and without residual β-cell function (RBF).

DESIGN AND PATIENTS

This was a cross-sectional study containing 136 prepubertal (hereof 15 RBF positive) and 206 pubertal (hereof 42 RBF positive) children/adolescents with T1D for 3-6 years as well as 40 prepubertal and 30 pubertal healthy controls. RBF was evaluated by meal-stimulated C-peptide.

MAIN OUTCOME MEASURES

Fasting serum levels of bioactive IGF (ie, the ability of serum to activate the IGF-1 receptor in vitro), total IGF-1, total IGF-2, and IGFBP-1 and -3.

RESULTS

Irrespective of pubertal status, patients with T1D showed lower bioactive IGF and total IGF-1, but higher IGFBP-1 as compared with controls (P < .05). When stratified according to RBF status, a positive RBF was associated with normalization of all IGF-related peptides but IGFBP-1 in prepubertal children (P < .05), whereas none of the IGF components were normalized in prepubertal, RBF-negative children. In pubertal children, total IGF-1 and bioactive IGF remained subnormal and IGFBP-1 supranormal, irrespective of RBF status (P < .05).

CONCLUSION

Independent of pubertal status, T1D was associated with an abnormal IGF system. However, a positive RBF status appeared important but only in prepubertal children, in whom all IGF components but IGFBP-1 were normalized. We speculate that the pubertal GH surge induces insulin resistance, which overrides the stimulatory effect that an RBF may exert on the liver-derived IGF system.

Impaired systolic blood dipping and nocturnal hypertension: an independent predictor of carotid intima-media thickness in type 1 diabetic patients

OBJECTIVE

Type 1 diabetes in children predicts a broad range of later health problems including an increased risk of cardiovascular morbidity and mortality. This study aimed to evaluate whether nocturnal hypertension and impaired nocturnal dipping affect atherosclerosis in children and adolescents with type 1 diabetes and to investigate the relationship between atherogenic risk factors and carotid intima-media thickness (CIMT).

METHODS

One hundred fifty-nine type 1 diabetic patients and 100 healthy controls were included in the study. We investigated metabolic and anthropometric parameters such as body mass index (BMI), waist circumference, fasting glucose and insulin, serum lipids, 24h ambulatory blood pressure monitoring (ABPM), and CIMT and compared these with those in control subjects (CS).

RESULTS

No difference was found between type 1 diabetic patients and CS in age, weight, waist/hip ratio, triglyceride, HDL-cholesterol level. However in children with type 1 diabetes, total cholesterol (p=0.016),and LDL-cholesterol (p=0.002) levels and CIMT (P<0.001) were greater than those of controls. It was determined that 10% of type 1 diabetic patients had dyslipidemia. In 23.2% of type 1 diabetic patients, ABPM showed arterial hypertension. CIMT was significantly higher in the hypertensive group than in the non-hypertensive group (P=0.003). Twenty-three (14.4%) diabetic patients had nocturnal hypertension. CIMT was significantly greater in the nocturnal hypertensive group (p=0.023). Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) dipping was significantly different in diabetic patients (P<0.001). CIMT was correlated positively with Hba1c (r=0.220, p=0.037), and negatively with SBP dipping (r=-0.362, p=0.020) in the diabetic patients. In stepwise regression analysis, Hba1c and SBP dipping emerged as a significant predictor of CIMT (β=0.300, p=0.044, β=0.398 p=0.009) contributing to 15.58% of its variability.

CONCLUSION

These results provide additional evidence for the presence of subclinical cardiovascular disease (CVD) and its relation to hypertension in type 1 diabetic patients. They also indicate a significant relation between nocturnal hypertension, SBP dipping and increased arterial stiffness. It is also important to note that our findings reveal significant relationships between HBA1c cardiovascular changes and underline the importance of glucose control to predict CVD.

Higher leptin is associated with hypertension: the Multi-Ethnic Study of Atherosclerosis

Adipokines are secreted from adipose tissue, influence energy homeostasis and may contribute to the association between obesity and hypertension. Among 1897 participants enrolled in the Multi-Ethnic Study of Atherosclerosis, we examined associations between blood pressure and leptin, tumor necrosis factor-α (TNFα), resistin and total adiponectin. The mean age and body mass index (BMI) was 64.7 years and 28.1, respectively, and 50% were female. After adjustment for risk factors, a 1-s.d.-increment higher leptin level was significantly associated with higher systolic (5.0 mm Hg), diastolic (1.9), mean arterial (2.8) and pulse pressures (3.6), as well as a 34% higher odds for being hypertensive (P<0.01 for all). These associations were not materially different when the other adipokines, as well as BMI, waist circumference or waist-to-hip ratio, were additionally added to the model. Notably, the associations between leptin and hypertension were stronger in men, but were not different by race/ethnic group, BMI or smoking status. Adiponectin, resistin and TNFα were not independently associated with blood pressure or hypertension. Higher serum leptin, but not adiponectin, resistin or TNFα, is associated with higher levels of all measures of blood pressure, as well as a higher odds of hypertension, independent of risk factors, anthropometric measures and other selected adipokines.

Associations of physical activity and fitness with adipocytokines in adolescents: the AFINOS Study

BACKGROUND AND AIMS

Adipocytokines may have a key role in the development of atherosclerosis and type 2 diabetes. The purpose of this study was to examine the independent and joint associations of physical activity (PA), cardiorespiratory fitness (CRF) and muscular fitness (MF) with adiponectin and leptin in adolescents.

METHODS AND RESULTS

A sample of 198 adolescents (96 girls), aged 13-17-year, was selected. Participants completed anthropometric measurements (height, weight, and waist circumference) and percentage of body fat (%BF) was estimated by bioelectrical impedance. PA was measured by accelerometer for 7-day. The 20-m shuttle-run test was used to assess CRF and two MF tests (handgrip strength and standing broad jump) were used to create an MF score. A cluster score of health status (0-3 risks) was created. Serum adiponectin and plasma leptin were also determined. Regression analyses controlling for age, sex, pubertal status and waist circumference showed that PA was not significantly associated with adiponectin and vigorous PA showed a significant inverse association with leptin. Both CRF and MF were significantly and inversely associated with adiponectin and leptin. Further analyses revealed that the 'healthy' group (0 risks) had significantly lower adiponectin and leptin than 'medium-healthy' (1 risk) and 'unhealthy' (2-3 risks) status groups.

CONCLUSIONS

PA, CRF and MF are inversely and jointly associated with adiponectin and leptin concentrations in adolescents.

Association between apolipoprotein E polymorphism and subclinic atherosclerosis in patients with type 1 diabetes mellitus

OBJECTIVE

The most important cause of morbidity and mortality in type 1 diabetes mellitus (DM) is atherosclerosis. Apolipoprotein E (Apo E) polymorphism is accused of being the genetic risk factor for atherosclerosis. The aim of the present study was to determine which Apo E polymorphism was related to atherosclerosis in patients with type 1 DM.

METHODS

Seventy-four patients with type 1 DM were enrolled in the study. Age, diabetes duration, daily insulin dose, microalbuminuria, and major cardiovascular risk factors including anthropometric and metabolic parameters were assessed in each patient. Non-invasive ultrasonographic measurements were also performed. For determination of Apo E genotype, DNA was extracted from venous blood from all subjects using standard methods. Apo E genotyping was performed using a PCR-restriction fragment-length polymorphism assay.

RESULTS

Systolic blood pressure and carotid artery intima-media thickness (CA-IMT) were increased in subjects with E4/E4 polymorphism. According to univariate analysis, when adjusted for all risk factors, genotypes did not differ for total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides (p>0.05). However, E3/E3, E3/E4 and E4/E4 genotypes were found to be associated with an increase in CA-IMT (p<0.001).

CONCLUSIONS

Our results suggest that the polymorphism associated with atherosclerosis in type1 DM is Apo E4/E4.

Associations between Fatness, Fitness, IGF and IMT among Obese Korean Male Adolescents

BACKGROUND

The purpose of this study was to investigate the association between obesity, fitness levels and cardiovascular (CVD) risk factors, and to identify the correlation between of insulin-like growth factor (IGF)-1, IGF binding protein-3 (IGFBP-3), and carotid intima media thickness (IMT) in Korean adolescents.

METHODS

A total of 225 high school males with a mean age of 16.96±0.23 years participated in this study, and their fatness and fitness levels, fasting glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, IGF-1, IGFBP-3, and IMT were measured.

RESULTS

The results showed that total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), fasting insulin, HOMA-IR, IGF-1, and IGFBP-3 levels were significantly higher in the most obese group than in the other two groups (tertiles). Muscular and cardiopulmonary fitness were negatively associated with weight, body mass index (BMI), fat mass, body fat, waist circumference (WC), fasting insulin, HOMA-IR, and IMT. IGF-1 and IGFBP-3 levels were correlated with WC, hip circumference (HC), fasting glucose, TG, HDL-C, fasting insulin, and HOMA-IR. IMT levels were significantly associated with weight, BMI, muscle mass, fat mass, percent body fat, WC, HC, systolic blood pressure, diastolic blood pressure and high-sensitivity C-reactive protein.

CONCLUSION

There was a significant association between increased obesity and decreased fitness and HOMA-IR, IGF, and IMT among adolescents.

Serum adipokine levels in type 1 diabetic patients: association with carotid intima media thickness

BACKGROUND

Adipokines are markers of insulin resistance and play a role in the atherosclerotic process. The association of adipokines with the macrovascular complications of type 1 diabetes mellitus (DM) needs to be determined. The aim of this study was to measure serum adiponectin, leptin, and resistin levels in type 1 DM patients and investigate their relationship with carotid intima media thickness (CIMT), a clinical marker of atherosclerosis.

METHODS

Seventy-five type 1 DM patients and 115 sex and age-matched healthy controls were included in the study. Serum adiponectin, leptin, and resistin levels were measured by the enzyme-linked immunosorbent assay (ELISA method). CIMT was assessed by Doppler ultrasonography.

RESULTS

Adiponectin levels in diabetics were higher (25.8±14.8 μg/mL vs. 5.5±7.3 μg/mL; P<0.0001) and leptin levels were lower than controls (9.4±6.2 ng/mL vs. 12.8±8.6 ng/mL; P=0.01). Resistin levels were also higher in the diabetic group compared to controls (2.1±1.4 ng/mL vs. 1.6±0.8 ng/mL; P=0.04). Adiponectin was correlated negatively with CIMT (r=-0.24, P=0.03), age (r=-0.30, P=0.02), BMI (r=-0.33, P=0.02), waist-to-hip ratio (WHR) (r=-0.38, P=0.01) and positively with creatinine (r=0.44, P=0.004). Leptin levels were correlated with total cholesterol (r=0.53, P=0.01) and high-density lipoprotein (HDL) (r=0.67, P=0.001). Resistin was correlated with CIMT (r=0.24, P=0.03) and systolic blood pressure (r=0.48, P=0.009). Multivariate analysis revealed resistin and creatinine to be independent predictors of CIMT among adiponectin, leptin, resistin, WHR, glycosylated hemoglobin (HbA1c), and creatinine.

CONCLUSIONS

Increased adiponectin correlates negatively and resistin positively with CIMT in type 1 diabetic patients, but adjusting for other known predictors reveals only resistin to be associated with subclinical atherosclerosis in this group of patients.

[Classic and emergent cardiovascular risk factors in schoolchildren in Asturias]

INTRODUCTION

Classic cardiovascular risk factors are present in infancy. C-reactive protein, leptin and adiponectin are the most important inflammatory cardiovascular risk markers.

PATIENTS AND METHODS

A descriptive, cross-sectional study, including children aged 6-12 years old from two local primary schools in the city of Avilés. Body measurements were made to determine the prevalence of obesity and overweight. Systolic and diastolic blood pressure was measured and the presence of metabolic syndrome was determined. Family income, dietary, and life-style habits were collected using the questionnaires GRAFFAR, KIDMED and Self-report instruments for measuring physical activity, respectively. Blood analysis included lipid profile, insulin resistance profile, liver profile, C-reactive protein, leptin and adiponectin.

RESULTS

A total of 459 schoolchildren were included of whom 31% were overweight and 10.9% were obese. Obese children were heavier with higher levels of body mass index, waist circumference, blood pressure, C- reactive protein, leptin, and lower levels of HDL-cholesterol and apolipoprotein A than non-obese children. No differences were found in physical and sedentary activities, but obese children had a worse quality diet than non-obese children.

CONCLUSIONS

Prevalence of obesity and overweight is reaching worrying levels in school age children. Obesity is associated with other classic and inflammatory cardiovascular risk factors. Obese children have a worse quality diet, although they do not do any less physical activities or any more sedentary than non-obese children.

Leptin receptor Lys109Arg and Gln223Arg polymorphisms are associated with early atherosclerosis

BACKGROUND

Leptin is a hormone expressed by the leptin gene, primarily in adipocytes, controlling food intake and energy expenditure. The effects of leptin are mediated by its receptor (LEPR) located in the central nervous system and other tissues, including adipocytes and endothelial cells. The aim of this study was to characterize two polymorphisms of LEPR, Lys109Arg (rs1137100) and Gln223Arg (rs1137101), as risk factors for early atherosclerosis. This connection has not been studied before.

METHODS

This study was performed in the randomly selected, middle-aged control subjects (n=526) from our well-defined OPERA (Oulu Project Elucidating Risk of Atherosclerosis) study. Analysis of covariance (ANCOVA) was performed to study the associations between genotypes, intima media thickness (IMT) measurements, and risk factors for atherosclerosis.

RESULTS

Subjects with the genotype Lys109Arg had the lowest body mass index (BMI) (P = 0.035), whereas Arg109Arg homozygotes had the highest total cholesterol (P=0.021) when adjusted for sex and age. Gln223Arg associated independently with systolic blood pressure (P=0.036). There were no differences in leptin concentrations between the genotypes. The adjusted (sex, age, BMI, smoking status, low-density lipoprotein cholesterol, systolic blood pressure, and fasting blood glucose) means for the IMT measurements were lowest in the Arg109 and Arg223 homozygotes (P=0.042 and P=0.041, ANCOVA, respectively).

CONCLUSIONS

The variations in the LEPR gene are independently associated with early atherosclerosis and some of its risk factors. These variations could possibly affect leptin signaling and thereby modify the effects of leptin on the atherosclerotic process.

Effectiveness of pentoxifylline on the cross-sectional area of intima media thickness and functions of the common carotid artery in adolescents with type 1 diabetes

OBJECTIVE

The aim of the present study was to evaluate the effect of oral pentoxifylline on the cross-sectional area of intima media thickness (CSA-IMT) and functions of the common carotid artery, a marker of early atherosclerosis, in adolescents with type 1 diabetes.

PATIENTS AND METHODS

Non-invasive ultrasonographic measurements were made in 56 type 1 diabetic patients. The diabetic patients were matched first in terms of age, diabetes duration, major cardiovascular risk factors, including anthropometric and metabolic parameters as well as ultrasonographic measurements, then one individual within each pair randomized into a pentoxifylline group and a placebo (control) group (i.e., 32 on pentoxifylline group and 24 on placebo). Pentoxifylline was administered for 6 months. We investigated the change of CSA-IMT, compliance, distensibility, diastolic wall stress (DWS), and incremental elastic modulus of the common carotid artery at 6 months after pentoxifylline.

RESULTS

In comparison of changes in common carotid artery measurements between the two groups, the pentoxifylline treatment group had significantly higher values than the controls for CSA-IMT (-2.6 +/- 0.1 vs. 0.7 +/- 0.4 mm2, p = 0.001) and for DWS (-0.38 +/- 0.02 vs. -0.05 +/- 0.05 mm Hg x 10(2), p < 0.001). In a multivariate regression model for all patients, being in pentoxifylline group was the best predictor of the change DWS (beta = -0.52, p < 0.001).

CONCLUSION

Our preliminary results suggest that pentoxifylline has an antiatherogenic action and might modulate risk factors for atherosclerosis in type 1 diabetes.

Atherogenic lipid profile and systolic blood pressure are associated with carotid artery intima-media thickness in children with Turner syndrome

OBJECTIVE

Women with Turner syndrome (TS) have greater carotid artery intima-media thickness (cIMT) known to be a risk factor for atherosclerosis in adults. To determine whether there are risk factors for atherosclerosis in children with TS, we compared cIMT, anthropometric and metabolic parameters between children with TS and healthy controls.

METHODS

Data of children with TS with XO karyotype (n=24, mean age: 11.6±3.6) were compared with those of healthy children (n=24, mean age: 10.5±3.6) with respect to anthropometric parameters, lipid levels, insulin resistance and cIMT which was measured by high resolution B-mode ultrasonography.

RESULTS

Mean age and cIMT values were similar in the two groups of children. However in children with TS, fasting glucose (p=0.01), total cholesterol (p=0.006), triglyceride (p=0.04) levels and HDL-cholesterol (p=0.002) levels were higher than those of controls. In the TS group, cIMT correlated positively with LDL-cholesterol (r=0.435, p=0.034) and with systolic blood pressure (r=0.430, p=0.036) and negatively with HDL-cholesterol (r=-0.518, p=0.01). In stepwise regression analysis, HDL-cholesterol emerged as a significant predictor of cIMT (b= -0.518, p=0.01) contributing to 26.8 % of its variability.

CONCLUSION

The systolic blood pressure and dyslipidaemia were shown to be risk factors for atherosclerosis in children with TS.

Biomarkers of obesity and subsequent cardiovascular events

Obesity is a major risk factor for cardiovascular diseases, but the mechanisms for increased cardiovascular risk in obesity are still unclear. Inflammation and increased oxidative stress are two potential mechanisms proposed to play a major role in the morbidity associated with obesity. Studies that investigate these mechanisms rely on biomarkers, but validated biomarkers for obesity-related cardiovascular outcomes are lacking. By finding optimal biomarkers, diagnostic criteria for cardiovascular diseases can be refined in the obese beyond "traditional" risk factors to identify early pathologic processes. The objective of this review is to identify potential early biomarkers resulting from obesity and associated with cardiovascular disease. Studies were initially identified through the search engine PubMed by using the keywords "obesity" and "biomarker." Subsequently, combinations of the keywords "obesity," "biomarker," "cardiovascular risk," "adipose tissue," "adipokine," "adipocytokine," and "oxidative stress" were used. The SOURCE database and Online Mendelian Inheritance in Man (OMIM) were used to obtain more information on the biomarkers. Results of the searches yielded a large number of potential biomarkers that occur in obesity and which either correlate with traditional cardiovascular risk factors or predict subsequent cardiovascular events. Several biomarkers are promising regarding their biologic properties, but they require further validation in humans.

Evidence for association between insulin resistance and premature carotid atherosclerosis in childhood obesity

The present study was undertaken to determine the presence and predictors of the subclinical atherosclerosis in obese children. Fifty obese children [mean age: 11.7 +/- 2.5 y, mean body mass index (BMI): 28.2 +/- 4.0 kg/m] and 50 age- and sex-matched healthy nonobese controls (mean age: 11.4 +/- 3.73 y, mean BMI: 17.6 +/- 3.0 kg/m) were enrolled in the present study. Oral glucose tolerance test was performed to all obese subjects. Common carotid artery intima-media thickness (IMT) was measured by high-resolution B-mode ultrasonography. Carotid artery IMT was significantly increased (0.0476 +/- 0.007 versus 0.033 +/- 0.011 cm; p < 0.001) in the obese group. There were significant relations between carotid artery IMT and insulin sensitivity indexes derived from fasting samples (fasting glucose to insulin ratio (FGIR; p = 0.004, r = -0.404), quantitative insulin-sensitivity check index (QUICK-I; p = 0.002, r = -0.401) and homeostasis model assessment of insulin resistance (HOMA-IR; p = 0.034, r = 0.300) in the obese group. In a multivariate regression model, QUICK-I emerged as independent correlates for mean IMT in obese children with the total variance explained being 20.7% (beta = -0.58, p < 0.001). We concluded that insulin resistance is an independent risk factor for increased carotid artery IMT in obese children.

Serum insulin-like growth factor-I (IGF-I) IGF binding protein-3 (IGFBP-3) and leptin levels are related to abdominal aortic intima-media thickness in macrosomic newborns

OBJECTIVE

Exposure to diabetes in utero has been established as a significant risk factor for some of the components of metabolic syndrome, and was associated with increased levels of maternal, placental, and fetal insulin-like growth factors and leptin. The atherogenic effects of leptin and insulin-like growth factor-I (IGF-I) have been extensively described. The present study was therefore designed to investigate relationships between abdominal aortic intima-media thickness (aIMT), serum IGF-I, IGF binding protein-3 (IGFBP-3) and leptin levels in macrosomic newborns.

DESIGN

Neonates whose birth weights exceed 90th percentile for gestational age and gender are termed macrosomic. Abdominal aortic intima-media thickness was measured in 30 macrosomic neonates of diabetic mothers (group A), 30 macrosomic neonates of healthy mothers (group B) and 30 healthy neonates (group C). Serum IGF-I, IGFBP-3 and leptin levels were determined in all infants and their mothers. Stepwise logistic regression analysis was used to determine independent risk factors for aortic intima-media thickness.

RESULTS

Mean aortic intima-media thickness was significantly higher in groups A and B (0.489+/-0.015,0.466+/-0.019 mm, respectively) than in controls (0.375+/-0.024 mm, p<0.0001). Weight-adjusted aortic intima-media thickness was significantly higher in-group A than in groups B (p=0.004) and C (p=0.048). Serum leptin concentration in-group B (37.4+/-10.7 ng/ml) was significantly greater than in-group C (23.5+/-7.1 ng/ml, p<0.0001), but significantly lower than in-group A (46.6+/-14.1 ng/ml, p<0.0001). Serum IGF-I levels of the infants were significantly lower in-group C (113.2+/-33.1 ng/ml) than in groups A and B (205.2+/-60.1 and 179.3+/-55.1 ng/ml respectively, p<0.0001). Serum IGF-I, IGFBP-3 and leptin levels of the infants were positively correlated with mean (p<0.0001) and weight-adjusted aortic intima-media thickness measurements (p=0.003, p=0.006 and p=0.001, respectively).

CONCLUSIONS

Macrosomic neonates of diabetic mothers have significantly increased aortic intima-media thickness with higher serum IGF-I, IGFBP-3 and leptin concentrations than those of controls. It might be speculated that these changes may exaggerate the atherosclerotic process later in life.

Arterial wall thickening and stiffening in children and adolescents with type 1 diabetes

OBJECTIVE

We evaluated structural and functional characteristics of the common carotid artery (CCA), a marker of early carotid atherosclerosis, and investigated their relation to metabolic and anthropometric parameters in children and adolescents with type 1 diabetes.

MATERIALS AND METHODS

Non-invasive ultrasonographic measurements were made in 45 type 1 diabetic patients and 33 controls. Age, sex, and body mass index were matched between patients and controls. We investigated intima-media thickness (IMT), compliance, distensibility, diastolic wall stress (DWS) and incremental elastic modulus (IEM) of the CCA. Metabolic and anthropometric parameters such as serum lipids, plasma glycated haemoglobin, body mass index, waist-hip ratio and blood pressure were assessed.

RESULTS

The diabetic patients had significantly higher CCA-IMT than the controls (0.48+/-0.06mm versus 0.33+/-0.07mm; p<0.001). The diabetic children had significantly higher values than the controls for DWS (1.18+/-0.29mmHgx10(2) versus 0.81+/-0.25mmHgx10(2); p<0.001) and for IEM (1.26+/-0.57mmHgx10(3) versus 0.77+/-0.28mmHgx10(3); p<0.001). The difference was not significant between patients and controls for arterial compliance and for distensibility (p>0.05). In a multivariate regression model for all subjects, diabetic state was the best predictor of IMT (p<0.001), DWS (p<0.001) and IEM (p=0.001).

CONCLUSION

Our results suggested that children and adolescent patients with type 1 diabetes are associated with early impairment of CCA structure and function and that diabetic state may be the main risk factor for CCA wall stiffening and thickening, which are of considerable concern as possible early events in the genesis of atheroma.

Evidence for an association between type 1 diabetes and premature carotid atherosclerosis in childhood

Acute phase proteins have been suggested to be increased in patients with type 1 diabetes. The aim of this study was to evaluate the relationship between serum C-reactive protein (CRP) and intima-media thickness (IMT) and functions of the common carotid artery (CCA) in children and adolescents with type 1 diabetes. Serum CRP levels were measured in 65 children and adolescents with diabetes (33 girls and 32 boys; mean age, 12.7 +/- 3.8 years; range, 7-18; duration of diabetes, 6.9 +/- 3.6 years). Age and diabetes duration, as well as major cardiovascular risk factors including anthropometric and metabolic parameters, were matched between girls and boys. The relations of serum CRP levels to CCA structure and functions were measured by ultrasonography as IMT, cross-sectional compliance, cross-sectional distensibility, diastolic wall stress (DWS), and incremental elastic modulus (IEM). There was no significant difference for serum CRP levels between girls and boys (3.7 +/- 1.3 vs 3.2 +/- 0.4 mg/L; p > 0.05). CRP was positively correlated with IMT (r = 0.49, p = 0.001), IEM (r = 0.24, p = 0.05), DWS (r = 0.58, p < 0.001), and body mass index (BMI) (r = 0.28, p = 0.05). In a multivariate regression model, we included CRP and metabolic and anthropometric parameters such as duration of diabetes, HbA1c, BMI, waist:hip ratio, age, and systolic and diastolic blood pressure as independent variables in the model for CCA structure and functions. CRP emerged as an independent correlation for mean IMT (beta = 0.51, p < 0.001) and DWS (beta = 0.61, p < 0.001). According to our findings, CRP was associated with CCA structure and functions in children and adolescents with type 1 diabetes.

Early atherosclerosis in childhood: diagnostic approaches and therapeutic strategies

The long preclinical phase of atherosclerosis involves the interaction of genetic and environmental factors that modulate the progression of disease from early life. Injury to the endothelium is a critical step in atherosclerotic process. Conventional and novel risk factors for coronary artery disease operate from early in life. Noninvasive methods, using mostly ultrasound techniques, have enabled the assessment of early functional and structural arterial disease progression even from the first decade of life. These measures have been shown to be good surrogate markers for atherosclerotic disease progression and future clinical cardiovascular events. Lifestyle and dietary modifications as well as pharmacological interventions have beneficial effects in prevention and restoration of the early arterial changes.

Leptin and atherosclerosis

Leptin, a 167-amino acid peptide hormone produced by white adipose tissue, is primarily involved in the regulation of food intake and energy expenditure. Leptin receptors are expressed in many tissues including the cardiovascular system. Plasma leptin concentration is proportional to body adiposity and is markedly increased in obese individuals. Recent studies suggest that hyperleptinemia may play an important role in obesity-associated cardiovascular diseases including atherosclerosis. Leptin exerts many potentially atherogenic effects such as induction of endothelial dysfunction, stimulation of inflammatory reaction, oxidative stress, decrease in paraoxonase activity, platelet aggregation, migration, hypertrophy and proliferation of vascular smooth muscle cells. Leptin-deficient and leptin receptor-deficient mice are protected from arterial thrombosis and neointimal hyperplasia in response to arterial wall injury. Several clinical studies have demonstrated that high leptin level predicts acute cardiovascular events, restenosis after coronary angioplasty, and cerebral stroke independently of traditional risk factors. In addition, plasma leptin correlates with markers of subclinical atherosclerosis such as carotid artery intima-media thickness and coronary artery calcifications. Inhibition of leptin signaling may be a promising strategy to slow the progression of atherosclerosis in hyperleptinemic obese subjects.