Deregulation of the growth hormone/insulin-like growth factor-1 axis in adults with cystic fibrosis

PURPOSE: Patients with cystic fibrosis (CF) present with signs and symptoms that overlap with those of adult growth hormone deficiency (GHD) syndrome: loss of muscle mass, bone fragility and lower stress tolerance. In literature, the prevalence of GHD in pediatric CF patients is higher than general population, but these studies have been performed on children with growth delay. To our knowledge, there are no studies on adult patients. The aim of this paper is to evaluate GH-IGF1 axis in an adult CF population. METHODS: Fifty clinically stable adult patients, 30 males; age 36 ± 2 years; BMI 21.39 ± 0.22 kg/m2 and FEV1 67 ± 4% were studied. Data regarding glycometabolic status and results of pituitary, thyroid, parathyroid, gonadal and adrenal function tests were recorded. All patients underwent a GH releasing hormone (GHRH) + Arginine stimulation test to confirm a GHD. RESULTS: GHRH + Arginine test revealed the presence of GHD in 16 patients (32%); specifically 7 patients had a severe deficiency and 9 a partial deficiency. CONCLUSIONS: Adult patients with CF may show GHD. These patients should be followed over time to assess if the GHD could impact the clinical progression of CF.