Attention-Deficit/Hyperactivity Disorder Medication Treatment Impact on Response to Growth Hormone Therapy: Results from the ANSWER Program, a Non-Interventional Study.

Objective: To examine whether attention-deficit/hyperactivity disorder (ADHD) stimulant medication modified the linear growth response to growth hormone (GH) treatment in children enrolled in the American Norditropin Studies: Web-Enabled Research Program.

Study Design: Short, GH treatment-naive children with or without GH deficiency (GHD) received GH therapy. A subset also received ADHD stimulant medication (n = 1190), and others did not (n = 7230). Linear mixed models (adjusted means) examined height SDS (HSDS) and body mass index (BMI) SDS from baseline through year 4. Analyses were repeated with ADHD groups matched for baseline age, height, weight, BMI, and sex. Groups with and without GHD were compared between ADHD groups.

Results: Adjusted change in HSDS for the group receiving ADHD stimulant medication was slightly lower than that for patients not receiving stimulant medication at years 1 to 4 (P < .05). However, adjusted change in HSDS was similar between children receiving and not receiving ADHD stimulant medication when matched for baseline measurements. At year 4, 86.7% of patients receiving ADHD stimulant medication, 86.8% of total patients not receiving ADHD stimulant medication, and 84.6% of matched group patients not receiving ADHD stimulant medication achieved HSDS >-2. Year 4 adjusted change in BMI SDS was greater in the patients receiving ADHD stimulant medication compared with both groups not receiving ADHD stimulant medication (P < .05). Patients with GHD showed comparable differences in adjusted change in BMI SDS among the ADHD groups at year 4, whereas patients without GHD showed no significant differences.

Conclusions: ADHD medication did not affect the linear growth response of children treated with GH when those receiving or not receiving ADHD stimulant medication were matched for baseline measurements. Underlying reasons for the observed greater increase in BMI in patients with GHD concomitantly treated with ADHD medication remain to be elucidated.

Trial Registration: ClinicalTrials.gov: NCT01009905.