Pediatric Cushing's syndrome: greater risk of being overweight or obese after long-term remission and its predictive factors.

Objective: Due to the rarity of Cushing's syndrome (CS) in children and adolescents, data are scarce about BMI during active disease and following remission. Therefore, our aim was to analyze BMI after long-term remission and determine predictive factors for promptly identifying patients at risk of being overweight or obese after remission for CS.

Design: Retrospective cohort study.

Patients: 73 patients: 58 (79.4%) had Cushing disease, 40 males (58%), median age of 12 years (IQR: 9-15). The mean follow-up time was 22.4 ± 18.2 months (range: 4-98).

Methods: Main outcome measures: BMI, lipid profile, blood pressure, HOMA-IR.

Results: At diagnosis, only eight (11%) patients had a normal weight. Although the BMI z-score at the last follow-up improved (2.0 ± 0.7 to 1.0 ± 1.2, P < 0.001), 44% remained overweight or obese after 2 years of remission according to the Kaplan-Meier curves. The BMI z-scores at the last follow-up correlated only with HOMA-IR levels (r: 0.49, P = 0.027). We found two independent factors related to reaching a normal weight: BMI z-score at diagnosis (HR: 0.156, 95% CI: 0.038-0.644; P = 0.01) and BMI z-score change at 6 ± 2 months (HR: 2.980, 95% CI:1.473-6.028; P = 0.002), which had high accuracy when a cut-off of 0.5 was used for ROC analysis (AUC = 0.828 (0.67-0.97); P < 0.001).

Conclusions: Children and adolescents with CS have a high risk of being overweight or obese after successful treatment for their disease. At risk patients can be identified quickly based on their baseline BMI and initial weight loss after surgery. Efforts should focus on adopting healthy diet and lifestyle in the immediate postoperative period.