Obesity after childhood craniopharyngioma - German multicenter study on pre-operative risk factors and quality of life

Background: Craniopharyngiomas are tumorous embryogenic malformations. As t he survival rate after craniopharyngioma is high (92%), prognosis and quali ty of life (QoL) in survivors mainly depend on adverse late effects such as obesity. Patients and methods: We analyzed 214 children and adolescents wi th craniopharyngioma. The records of 185 patients (86%) were available for retrospective analysis of weight profiles and risk factors for obesity. Qua lity of life (QoL) was measured in 145 patients by the Fertigkeitenskala Mu nster/Heidelberg score (FMH) and in 77 patients by PEDQOL questionnaire. Re sults: Eighty-two of 185 patients (44%) developed severe obesity (body mass index [BMI] > 3 SD). Obese patients were compared with 79 patients (43%) w ho kept normal weight (BMI < 2 SD). No differences between obese and normal weight patients were found in terms of gender distribution, age at diagnos is and follow-up period. However, the BMI SDS at the time of diagnosis was higher (p < 0.0001) in patients who developed obesity than in those who did not. Furthermore, obese patients presented with bigger tumors (p < 0.05) a nd a higher rate of a hydrocephalus requiring a shunt (p < 0.05) and hypoth alamic involvement (p <less than> 0.05). The mothers of patients who develo ped severe obesity had a higher BMI (p < 0.001) at the time of diagnosis. O bese patients had a higher height-SDS at diagnosis (p < 0.05) and at the ti me of last follow-up (p < 0.05) when compared with normal weight patients. A prediction model for severe obesity after craniopharyngioma was calculate d by logistic regression based on the risk factors: patient's BMI > 2 SD at diagnosis (p < 0.05; odds ratio: 16.4), hypothalamic involvement (p < 0.05 ; odds ratio: 3.4) and maternal BMI > 25 kg/m(2) (p < 0.05; odds ratio: 4.6 ). Significant increases in BMI (p < 0.001) occurred during the early post- operative period especially during the first three years after diagnosis. F MH percentiles correlated negatively with BMI SOS (Spearman r: -0.37; p < 0 .001). Children with craniopharyngioma rated their QoL more negative (p < 0 .05) in regard to physical abilities, cognitive functioning and social func tioning when compared with healthy children of the same age group. Severely obese patients with craniopharyngioma estimated their QoL lower (p < 0.05) for all domains except for autonomy, cognition and familial integration in comparison with non-obese patients. Conclusion: Hypothalamic tumor involve ment and familial disposition for obesity are risk factors for the developm ent of severe obesity in patients with craniopharyngioma. As weight gain st arts early after diagnosis and severe obesity causes a reduction in QoL, ea rly therapeutic efforts should be considered in patients at risk. To confir m our results the prospective multicenter study Kraniopharyngeom 2000 on ch ildren and adolescents with craniopharyngioma was initiated (www.kraniophar yngeom.com).