Metabolic health of young adults who were born small for gestational age and treated with growth hormone, after cessation of growth hormone treatment: a 5-year longitudinal study

Summary Background Growth hormone treatment reduces fat mass and insulin sensitivity and increases lean body mass. Data are only available for short-term longitudinal changes after cessation of growth hormone treatment in young adults born small for gestational age. We aimed to assess long-term changes over a 5-year period following cessation of growth hormone treatment. Methods We did a longitudinal study of young adults born small for gestational age and previously treated with growth hormone. Individuals were followed up for 5 years after attainment of adult height, when growth hormone treatment was discontinued: assessments were done at cessation of growth hormone treatment and at 6 months, 2 years, and 5 years thereafter. Data 5 years after cessation of growth hormone were compared with untreated age-matched controls. We used dual-energy x-ray absorptiometry to assess body composition, and did frequently sampled intravenous glucose tolerance tests to assess insulin sensitivity, acute insulin response, and the disposition index (a measure of β-cell function). This study is registered with ISRCTN, numbers ISRCTN96883876 and ISRCTN65230311. Findings Between April, 2004, and April, 2016, we followed up 199 young adults born small for gestational age and previously treated with growth hormone, during the 5 years after cessation of growth hormone treatment. Data at 5 years for these individuals were compared with those for 51 untreated adults born small for gestational age with short stature, 92 untreated adults born small for gestational age with spontaneous catch-up growth, and 142 adults born appropriate for gestational age and unexposed to growth hormone treatment. In young adults born small for gestational age and previously treated with growth hormone, 5 years after cessation of growth hormone treatment, there were increases in fat mass (estimated marginal mean 10·73 kg [95% CI 9·95–11·50] at cessation of treatment vs 16·12 kg [14·77–17·46] at 5 years; p