Endothelial function and mechanical properties of the common carotid artery in children on parenteral nutrition

Cardiovascular risk factors in children with type 1 diabetes mellitus

Objective Cardiovascular disease is a major complication among children with type 1 diabetes mellitus (T1DM). This prospective study aimed at examining the presence of cardiovascular risk factors in children with T1DM. Methods We evaluated several cardiovascular risk factors, including atherosclerosis, artery intima-media thickness (IMT) and metabolic responses, in 175 children with T1DM, with 150 non-diabetic children as normal controls. Results The diabetic children had significantly higher carotid IMT (cIMT) and aortic IMT (aIMT), higher values for diastolic wall stress (DWS), incremental elastic modulus (IEM), and flow-mediated dilatation (FMD) than the controls. The levels of tumor necrosis factor-α (TNF-α), interleukin-4 (IL4), high-sensitivity C-reactive protein (hs-CRP) and leptin were significantly higher in T1DM patients. In T1DM children, the cIMT and aIMT were correlated with several risk factors, including age, weight, body mass index (BMI), duration of diabetes, waist/hip ratio, as well as levels of total cholesterol, triglycerides and apolipoprotein B (apoB). In addition to common risk factors, cIMT was also associated with systolic blood pressure (BP). Other risk factors, such as height, diastolic BP, low-density lipoprotein (LDL)/high-density lipoprotein (HDL)-cholesterol ratio, apolipoprotein A1 (apoA1) and S-creatinine levels, were not all independent risk factors of cardiovascular disease in T1DM children. Conclusions T1DM is associated with early impairment of the common carotid and aortic artery structure and function, and the diabetic state may be the main risk factor for arterial wall stiffening and thickening.

Radiotherapy-related arterial intima thickening and plaque formation in childhood cancer survivors detected with very-high resolution ultrasound during young adulthood

BACKGROUND

The aim of the study was to evaluate arterial morphology and function in a national cohort of long-term survivors of high-risk neuroblastoma (NBL) treated with high-dose chemotherapy and autologous hematopoietic stem cell transplantation with or without total body irradiation (TBI).

METHODS AND RESULTS

Common carotid, femoral, brachial, and radial artery morphology were assessed with very-high-resolution vascular ultrasound (25-55 MHz), and carotid artery stiffness and brachial artery flow-mediated dilatation measured with conventional vascular ultrasound in 19 adult or pubertal (age 22.7 ± 4.9 years, range 16-30) NBL survivors transplanted during 1984-1999 at the mean age of 2.5 ± 1.0 years. Results were compared with 20 age- and sex-matched healthy controls. The cardiovascular risk assessment included history, body mass index, fasting plasma lipids, glucose, and 24-h ambulatory blood pressure (BP). The survivors had consistently smaller arterial lumens, increased carotid intima-media thickness (IMT), plaque formation (N = 3), and stiffness, as well as increased radial artery intima thickness (N = 5) compared with the control group. Survivors displayed higher plasma triglyceride and cholesterol levels, and increased heart rate, as well as increased systolic and diastolic BPs. TBI (N = 10) and a low body surface area were independent predictors for decreased arterial lumen size and increased IMT. Three out of five survivors with subclinical intima thickening had arterial plaques. Plaques occurred only among TBI-treated survivors.

CONCLUSIONS

Long-term childhood cancer survivors treated with TBI during early childhood display significant signs of premature arterial aging during young adulthood.

Time-related arterial changes after allogeneic hematopoietic stem cell transplantation in children

BACKGROUND

Metabolic syndrome is a frequent late effect in young adults after hematopoietic stem cell transplantation (HSCT) performed in childhood.

METHODS

To further study the signs of cardiovascular changes in HSCT patients, we performed noninvasive vascular ultrasonic measurements of arterial stiffness and endothelial function in 25 children (median age: 11.2 y) and in 22 healthy matched controls.

RESULTS

The distensibility of the common carotid artery (CCA) was significantly lower in the patients than in the controls (mean = 0.48, SD = 0.19 vs. mean = 0.64 mm Hg(-1) × 10(-2), SD = 0.28; P = 0.024). The distensibility decreased with time passed after HSCT (P = 0.009). The compliance of the CCA was decreased (mean = 0.10, SD = 0.04 vs. mean = 0.13 mm(2) × mm Hg(-1), SD = 0.05; P = 0.041), and the incremental elastic modulus (E inc) was higher in the patients than in the controls (mean = 2.05, SD = 0.7 vs. mean = 1.6 mm × 10(3), SD = 0.6; P = 0.019). E inc was associated with time passed after HSCT (P = 0.036). The size of the brachial artery and flow-mediated dilation did not differ between the groups.

CONCLUSION

Early mechanical changes of the arterial wall were found at young age after HSCT. Ultrasonography may offer a noninvasive method to find early alterations of the vascular bed and to optimize prevention of atherosclerosis in HSCT patients.

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.