Purpose: Acromegaly is a cause of secondary osteoporosis and is associated with increased risk of vertebral fractures (VFs). The influence of exon 3-deleted isoform of growth hormone receptor (d3-GHR) on bone microarchitecture has not been studied in acromegaly.
Aim: The aim of this study was to analyze the associations between d3-GHR isoform and bone mineral density (BMD), bone microarchitecture, and VFs in acromegaly patients.
Methods: Consecutive acromegaly patients treated at a single reference center were included. BMD was analyzed using dual-energy X-ray absorptiometry (DXA) and bone microarchitecture was analyzed by high-resolution peripheral quantitative computed tomography (HR-pQCT). The presence of moderate to severe VFs was assessed by thoracic and lumbar X-ray. GHR genotyping was analyzed by PCR, and full-length isoform of GHR (fl-GHR) was represented by a 935-bp fragment and d3-GHR by a 532-bp fragment.
Results: Eighty-nine patients were included [56 females; median age at diagnosis: 43 years (17-78)]. Disease was uncontrolled in 63% of patients. At least one d3-GHR allele was present in 60% of patients. Frequency of active disease (p = 0.276) and hypogonadism (p = 1.000) was not different between patients with fl-GHR and those with at least one d3-GHR. There was no difference in any DXA or HR-pQCT parameters between patients with fl-GHR and those with d3-GHR. Significant VFs were observed in 14% of patients, but there was no difference in frequency between patients with fl-GHR and those with at least one d3-GHR allele (p = 0.578).
Conclusions: Presence of d3-GHR was not associated with worse BMD or bone microarchitecture or with higher frequency of significant VFs.
Keywords: Acromegaly; Bone; Growth hormone receptor polymorphism; Osteoporosis.