The effects of Growth hormone treatment discontinuation in Adults on Metabolic profile, Body composition and quality Of Life (GAMBOL Study).

BACKGROUND: In adults, treatment of GHD with daily GH injection has been shown to improve many clinical features associated with GHD. Currently, many adults with GHD receive GH treatment indefinitely. Short and medium-term studies have demonstrated beneficial effects of GH replacement therapy, including improvements in body composition, metabolic parameters and quality of life. However, uncertainty remains regarding the long-term sustainability of these benefits and the consequences of treatment discontinuation. A randomised controlled trial is needed to understand the impacts of discontinuing long-term GH therapy in adults. Prior to embarking on an RCT, the feasibility of a discontinuation study and the acceptability of randomisation to patients and clinicians need to be assessed. Research aims (a) to explore the current practice of offering discontinuation of long-term GH treatment in adults in the UK and (b) to assess the feasibility of conducting an RCT evaluating GH treatment discontinuation in adults with GHD.

METHODS: This multi-method study comprises of three phases. •Phase 1: An online survey of endocrine clinicians' practice of offering discontinuation of long-term GH therapy in adult patients with GHD.•Phase 2: Feasibility cohort study involving two groups of adult patients with GHD (aged more than 25 years), who have been on GH treatment for at least 5 years.: (a) an intervention group consisting of 20-25 patients who will be discontinuing their long-term GH treatment for two years and (b) a control group consisting of 20-25 patients who will continue with their GH treatment.•Phase 3: Qualitative study. 10-16 participants will be recruited to explore their experiences of participation in the feasibility study using semi-structured interviews. Potential benefits This study will provide evidence of current GH treatment discontinuation practice in the UK and determine the feasibility of any future RCT. Long-term, this could promote and underpin the development of the much-needed relevant clinical guidance.