APOSTrophe Study (Parenteral Nutrition and Bone Trophicity) Impact of a Long-term Parenteral Nutrition on Bone Metabolism Measured by High Resolution Peripheral Quantitative Computer Tomography (HR-pQCT) in Children and Young Adults

Parenteral Nutrition and Bone Trophicity

Recent progress in parenteral nutrition has contributed to improve vital prognosis and to reduce morbidity in patients with severe intestinal failure.

Currently, home parenteral nutrition is the only alternative to prolonged hospitalization for those patients. However, long-term parenteral nutrition can result in complications especially in bone, such as osteopenia or osteomalacia, then increasing the risk of fractures. Children are especially at risk because of bone growth and peak mineralization acquisition during puberty.

Moreover, frequency and risk factors of those complications are not well documented for children.

Dual-energy X-ray Absorptiometry (DXA) is considered as the golden standard for bone mineralization measurement. In pediatrics, this technique has some limits such as the underestimation of Bone Mineral Density (BMD) in short stature, the overestimation of the BMD in tall children, and the inability to distinguish cortical from trabecular bone or to evaluate the bone microarchitecture.

HR-pQCT, High Resolution peripheral Quantitative Computed Tomography enables noninvasive assessment of bone microarchitecture (virtual bone biopsy) using a radiation similar to DXA. However this technique has never been validated in patients with long-term parenteral nutrition.

During the usual follow-up of the patients, HR-pQCT will be the only exam which will come in addition to the routine medical tests.

Inclusion Criteria:

• Patient who's receiving a long-term parenteral nutrition (over 2 years)
• Patient between 9 and 30 years of age (children big enough to stay immobile for 3 min during the measurement)
• Affiliation to the Social Security System
• Informed consent form signed by parents and assent given by the patient

Exclusion Criteria:

• Patient presenting a bone disease which is not directly related to the parenteral nutrition.
• Long-term corticotherapy ( over 6 months of therapy)
• Inability to keep the leg or the arm immobile for 3 min
• Patient not affiliated to a Social Security System
• Patient participating to another interventional study
• Pregnant patient or patient who desires pregnancy
• All situation that the physician estimated that is not compatible with the study