Effect of Diazoxide on the Obesity Secondary to Hypothalamic-pituitary Lesions

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