Perioperative dexamethasone treatment in childhood craniopharyngioma--influence on short-term and long-term weight gain.

The substitution of dexamethasone during and after surgery of childhood craniopharyngioma is necessary in order to treat and/or prevent brain edema and adrenal insufficiency. Early post-operative weight gain is a predictor for severe obesity during long-term follow-up. In a retrospective analysis of 60 patients with childhood craniopharyngioma we inquired whether dose and duration of perioperative dexamethasone therapy (n = 68) had influence on short-term post-operative weight gain and long-term development of severe obesity. The median follow-up period was 4.2 years, ranging from 1 to 9 years. 24 patients (14 f/10 m) developed severe obesity (BMI > 3 SD). 28 patients (10 f/18 m) retained normal weight (BMI < 2 SD). Eight patients presented with a BMI between 2 and 3 SD at the final visit. Differences in terms of age at surgery or follow-up period were non-detectable between the analyzed groups of craniopharyngioma patients. Duration and cumulative dexamethasone doses (mg/m2 BSA) for perioperative dexamethasone therapy were similar for severely obese patients (duration: 8.7 d; 4.5 - 17 d, cumulative dose: 74; 42 - 177 mg/m2 BSA) and normal weight patients (duration: 10.0 d; 1 - 41 d; dose: 76; 9 - 390 mg/m2 BSA). Whereas cumulative dexamethasone doses positively (p < 0.01; rho: 0.424) correlated with weight gain during the first year following surgery, long-term development of severe obesity was not influenced by dose and duration of perioperative dexamethasone treatment. Patients who developed severe obesity during follow-up had a higher (p < 0.001) BMI already at the time of diagnosis. We conclude that dose and duration of perioperative dexamethasone treatment had short-term effects on post-operative weight gain, but not on the development of long-term severe obesity. The results of our retrospective analysis are currently tested in a prospective surveillance study Kraniopharyngeom 2000 (www.kraniopharyngeom.com).