Diagnosing metabolic syndrome in craniopharyngioma patients: Body composition versus BMI

Objective: Craniopharyngioma patients often have poor metabolic profiles due to hypothalamic-pituitary damage. Previously, using BMI as obesity marker, the occurrence of the metabolic syndrome in these patients was estimated at 46%. Our aim was to determine if dual X-ray absorptiometry ( DXA) scan in evaluation of obesity and metabolic syndrome would be superior. Design: Retrospective study of craniopharyngioma patients for whom DXA scan results were available. Methods: BMI, fat percentage and fat mass index were used to evaluate obesity and as components for obesity in metabolic syndrome. Results: Ninety-five craniopharyngioma patients were included (51% femal e, 49% childhood-onset disease). Metabolic syndrome occurred in 34-53 (45-51%) subjects (depending on the definition of obesity, although all definitions occurred in higher frequency than in the general population). M etabolic syndrome frequency was higher if obesity was defined by fat percentage (52 vs 42%) or fat mass index (51 vs 4 3%) compared to BMI. Misclassification appeared in 9% (fat percentage vs BMI) and 7% (fat mass index vs BMI) for m etabolic syndrome and 29 and 13% for obesity itself, respectively. For metabolic syndrome, almost perfect agreement was found for BMI compared with fat percentage or fat mass index. For obesity, agreement was fair to moderate (BM I vs fat percentage). Conclusion: Using BMI to evaluate obesity underestimates the true prevalence of metabolic syndrome in patients with craniopharyngioma. Furthermore, fat percentage contributes to a better evaluation of obesity than BMI. The contribution of DXA scan might be limited for identification of the metabolic syndrome.