GH Responsiveness before and after a 3-Week Multidisciplinary Body Weight Reduction Program Associated with an Incremental Respiratory Muscle Endurance Training in Obese Adolescents

Several studies have demonstrated that the obesity-related hyposomatropism is usually reversible after a consistent weight loss induced by diet and/or bariatric surgery. Recently, a single bout of respiratory muscle endurance training (RMET) by means of a specific commercially available device (Spiro Tiger^®) has been reported to induce a marked GH response in obese adults, its GH-releasing effect being significantly lower in obese adolescents. The GH response disappeared in both obese adults and adolescents when RMET was repeated at 2-h intervals in-between. The aim of the present study was to evaluate GH responses to repeated bouts of RMET administered before and after a 3-week in-hospital multidisciplinary body weight reduction program (entailing energy-restricted diet, 90 min/daily aerobic physical activity, psychological counseling, and nutritional education) combined with a progressively increasing RMET (15 daily sessions, 5 sessions per week) in 7 obese male adolescents [age: 12-17 years; body mass index (BMI): 38.5±3.1 kg/m²; percent fat mass (FM): 37.0±2.0%]. Blood samplings for GH determinations were collected during the 1^st and 15^th sessions, which were composed of 2 consecutive bouts of RMET (of identical intensity and duration) at 2-h interval in-between. At the beginning of the study, baseline GH levels significantly increased after the first bout of RMET in all subjects (p