High prevalence of radiological vertebral fractures inpatients With TSH-secreting pituitary adenoma

Background: Bone loss and high risk of fractures have been reported in patients with primary hyperthyroidism, whereas data on skeletal health in TSH-secreting adenoma (TSH-oma) are scant, and the risk of fractures in this specific clinical context has not been investigated so far. In this crosssectional study, we aimed at evaluating for the first time, to our knowledge, the prevalence and determinants of radiological vertebral fractures (VFs) in patients with TSH-oma. Methods: Twenty-two patients (10 males, 12 females; median age 47 years) with TSH-oma and 44 patients (20 males, 24 females; median age 49 years) with nonfunctioning pituitary adenoma (NFPA) were retrospectively evaluated for thoracic VFs using a morphometric approach on lateral chest X-ray routinely performed in the presurgical diagnostic workup. Results: The prevalence of VFs was significantly higher in TSH-oma vs NFPA (59.1% vs 22.7%; P = 0.003), the difference being still significant (odds ratio, 10.5; P = 0.005) after correction for the size of pituitary adenomas and biochemical parameters. In TSH-oma, the prevalence of VFs was significantly associated with older age (P = 0.007) and higher serum free T4 values (P = 0.02). In 20 patients, data on presurgical medical therapies of TSH-oma were available. All patients not treated with somatostatin receptor ligands were fractured compared with 25% of those who were treated with these drugs (P = 0.001).No significant (P = 0.25) association between VFs and treatmentwithmethimazole was found. Conclusions: This study provides the first evidence, to our knowledge, that patients with TSH-oma may develop VFs in close relationship with severity of hyperthyroidism.