Background: patients with childhood-onset craniopharyngioma (CO-CP) present long-term outcomes, including growth hormone (GH) deficiency and obesity. Currently, data on the effects of GH therapy (GHT) on the body mass index (BMI) in CP are inconclusive. Aims of the study were to evaluate BMI over time and its determinants in a large cohort of CO-CP patients treated with GH therapy (GHT).
Methods: a multicenter retrospective study conducted by the Italian growth working group of the Italian Society of Pediatric Endocrinology involved 117 CO-CP subjects treated with GHT, followed between 2000 and 2018. Seventy-five underwent transcranial-TC, and 34 transsphenoidal-TNS surgery. Height SDS, BMI SDS, Tanner stage, GHT start (GHS) date, GH dose were collected at the time of CF diagnosis (n=78), 4-6 months after surgery (n=95), GHS (n=112), pubertal induction/start (n=78) and final height (FH, n=46). Forty-six patients presented a CF relapse.
Results: GHT improved height (P<0.0001) from GHS to FH, while BMI SDS only slightly decreased (P=0.23). Overall, BMI steeply increased after surgery (from 0.8±1.7 to 1.7±1.6SDS; +0.8SDS, P<0.0001) and decreased from GHS up to puberty (-0,36SDS, P<0.0001). No gender differences were observed. The TC group displayed a higher BMI SDS than the TNS surgery group already at CF diagnosis, after surgery and at GHS (all P<0.01); at FH a borderline difference persisted (P=0.08). Age at GHS was 10.7±4.1 yrs, at puberty 13.3±1.6 yrs. GHT was initiated at a mean dose of 4.9±2.3 mcg/m2/week; within 6 mts after surgery in 15 (12.8%), 12 mts in 26 (22.2%), 24 mts in 36 (30.8%) and >24 mts in 40 (34.2%). The latter group showed higher BMI SDS than patients that started earlier (P<0.01); BMI differences persisted up to FH. BMI SDS at FH was predicted by BMI SDS at GHS (coeff 0.93, P<0,0001) and negatively by GHT duration (coeff 0.132, P=0.03), but not by GHT dose (R2 0.611). Twenty-six patients (58,7%) relapsed before and 19 (41,3%) after GHS (P=0.49).
Conclusion: we demonstrated in our large cohort of CO-CP that GHT improved height and slightly BMI SDS at the time of puberty but not at FH; however, most patients started GHT later than 6 mts after surgery. TNS surgery, a longer GHT duration and a lower BMI at GH start seem associated to a lower BMI over time. The actual dose does not increase the risk of CP recurrence; studies are needed to evaluate the impact of different GH doses on BMI.
21 Sep 2023 - 23 Sep 2023