In children treated for intracranial lesions, the 2 factors of the obesity are : the location of the lesion (hypothalamic-pituitary region) and craniopharyngiomas

Approximately 80 % of the hypothalamic-pituitary lesions that occur in children are craniopharyngiomas with one or three cases per 1 million children each year.

One major problem remains unsolved : the obesity

This study is performed to optimize the management of the children with hypothalamic-pituitary lesions by reducing the hyperinsulinemia due to the lesion and the surgery

Inclusion Criteria:

• Age 6 to 18 years
• Obesity with body mass index > 97 percentile or > 2 SD
• Hypothalamic-pituitary lesions not evolutive
• Hyperinsulinemia defined by insulin peak after oral glucose tolerance test>100 UI/L
• Absence of diabetes mellitus defined by basal plasma glucose < 1.2 g/L and glucose peak after oral glucose tolerance test < 2 g/L and HbA1c < 7 %
• Hormonal replacement therapy stable from at least three months excluding the treatment of diabetes insipidus which can be adjusted
• Normal plasma thyroxine
• Written informed consent of the children and the parents

Exclusion Criteria:

• evolutive lesion
• recent surgery or radiotherapy (< 6 months)
• modification of hormonal replacement therapy during the three previous months
• diabetes mellitus defined by basal plasma glucose > 1.2 g/L and glucose peak after oral glucose tolerance test > 2 g/L and HbA1c > 7 %
• renal or hepatic failure
• uncontrolled hypertension
• hypersensitivity to benzothiazine drugs
• pregnancy
• difficulties to understand the protocol