Principal objective : Validation of a handy biochemical parameter, plasma concentration of Asymmetric DimethylArginine (ADMA), based on a recognize biochemical parameter, the dilation of the brachial artery, at ultrasound examination, after the deflation of a cushion to evaluate artery dysfunction (vascular suffering) in growth diseases, growth hormone deficiency (GHD) and intrauterine growth retardation (IUGR)

Secondary objectives:

• Comparison of ADMA plasma concentrations with dose of matched healthy control children
• Investigation of the mechanisms of arterial dysfunction, inflammation, oxidative stress and insulin resistance.

Inclusion Criteria:

• Group A: GHD, defined by 2 GH peaks less than 6.6 ng/ml (20 mU/L) at two stimulation tests
• Group B: IUGR, defined by a birth length and/or a birth weight inferior to - 2 SD for gestational age according to Usher and McLean charts
• Group C: Control children matched to children matched to subjects of groups A and B, according to gender and age
• Informed consent signed by representative of the parental authority

Exclusion Criteria:

• Chronic disabling disease (ex: diabetes, severe asthma)
• Evolving cancer
• Severe psychiatric disorder (ex: autism, schizophrenia; severe depression)
• Hypothalamic tumor (ex: craniopharyngioma)
• Anamnesis of cranial irradiation
• Overweight, obesity or thinness
• Precocious puberty
• Non-replacing therapy by glucocorticoids or sex steroids less than 1 month before the exploration
• Anterior treatment by recombinant human GH
• Other conditions, treatments or habits impacting arterial reactivity: acrocyanosis, cryoglobulinemia, beta adrenergic blocking habits, tobacco smoking or other drug addictions, dyslipidemia
• Pregnancy or lactation
• Acute infection less than three weeks before the investigation
• Participation to a therapeutic protocol
• Impossibility for the representatives of the parental authority to understand the objectives of the protocol
• Absence of social security coverage. Refusal by the parents to sign the informed consent or oral refusal by the child to participate to the study

pediatric patients with growth disorders and matched control children