Growth hormone secretion in adult patients with thalassaemia

Growth retardation and short stature are frequent clinical features of patients with beta-thalassaemia major. Dysfunction of the GH-IGF-1 axis has been described in many thalassaemic children and adolescents with short stature and reduced growth velocity. Several studies have demonstrated that recombinant GH treatment improves growth velocity in these patients, although response to the treatment is variable and not predictable. A reassessment of the GH-IGF-1 axis must be performed in young adults with childhood-onset GH deficiency (GHD), after attainment of final height, to select those who are candidates for replacement therapy as adults. To our knowledge there are no data available on retesting the GH-IGF-1 axis in adult thalassaemic patients with childhood-onset GHD. The aim of our study was to investigate GH secretion in adult thalassaemic patients with childhood-onset GHD.

We reassessed GH secretion in a group of adult thalassaemic patients in whom partial GHD had been diagnosed during childhood.

We performed an arginine plus GH-releasing hormone (GHRH) stimulation test in 16 thalassaemic patients (10 males, six females) with a mean age of 24.8 +/- 3.6 years. The cut-off level for GH response was set at 9 microg/l, according to the literature. Ferritin, IGF-1, liver enzymes and lipid levels were also determined.

We found persisting GHD in three patients, one patient had borderline values (GH peak = 10.4 microg/l), whereas the others had a normal response. These results are in accordance with the data on GH retesting in adult patients with idiopathic partial childhood-onset GHD.

We conclude that GH status should be retested in adult thalassaemic patients with childhood-onset GHD. If the diagnosis of adult GHD is established, GH treatment may be considered as it could contribute to improve heart function and bone mineral density, which are frequently impaired in adult thalassaemic patients.