Bone MicroArchitecture in Acromegaly

Study Overview
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Brief Summary
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The investigators will conduct a cross-sectional study of bone density, bone microarchitecture, vertebral fractures and trabecular bone score in 25 patients with acromegaly treated with Pegvisomant, the growth hormone (GH) receptor antagonist for at least 1 year and with normal insulin-like growth factor-1 (IGF-1) levels. This study aims to describe the bone architecture and associated biochemical indices of bone turnover and metabolism in patients with active acromegaly and how these are altered with treatment of the disease.

Detailed Description
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Growth hormone (GH) and Insulin-Like Growth Factor-1 (IGF-1) are important regulators of bone modeling and remodeling, fundamental to maintenance of normal skeletal integrity. In acromegaly, a disease characterized by longstanding exposure to excess GH and IGF-1, these hormones induce marked skeletal changes. Most dual energy X-ray absorptiometry (DXA) studies report that bone mineral density (BMD) is normal in acromegaly. Despite this, however, there is mounting evidence that bone health is adversely affected in patients with both active and successfully treated acromegaly.

Official Title
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Cross-sectional Study of Bone Density, Bone Microarchitecture, Vertebral Fractures and Trabecular Bone Score in Patients With Acromegaly Treated With Pegvisomant Compared to Patients With Untreated Active Acromegaly

Conditions
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Acromegaly, Osteoporosis Risk

Intervention / Treatment
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* Drug: Pegvisomant


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Individuals with acromegaly On pegvisomant therapy with a normal IGF-1 level for at least 1 year Exclusion Criteria: Malignancy (except cured basal, squamous cell skin carcinoma or other cured cancers free from recurrence > 3 years) Pregnancy or lactation within last 12 months Untreated primary hyperparathyroidism, hyper- or hypothyroidism Cushing's syndrome Prolactin-secreting pituitary adenoma GH deficiency On current drug therapy for osteoporosis Diabetes mellitus Renal insufficiency Liver disease Current or past use of glucocorticoids (more than physiologic dose), anticonvulsants, anticoagulants, methotrexate, aromatase inhibitors

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Acromegaly patients on pegvisomant<br>25 subjects with acromegaly on pegvisomant therapy with a normal IGF-1 level for at least 1 year. | Drug: Pegvisomant<br>* Subjects receiving pegvisomant as part of their clinical care for acromegaly will be studied.<br>* Other names: Somavert;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Volumetric bone mineral density of radius (vBMD) | Volumetric bone mineral density of radius (vBMD) measured by high resolution peripheral quantitative computed tomography (HRpQCT) | Measured once at one study visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Trabecular number of radius (TbN) | HRpQCT determined bone microarchitecture | Measured once at one study visit | 
| Trabecular Thickness of radius (Tb.Th) | HRpQCT determined bone microarchitecture | Measured once at one study visit | 
| Trabecular separation of radius (Tb.Sp) | HRpQCT determined bone microarchitecture | Measured once at one study visit | 
| Cortical density of radius | HRpQCT determined bone microarchitecture | Measured once at one study visit | 
| Cortical thickness of radius | HRpQCT determined bone microarchitecture | Measured once at one study visit | 
| Areal bone mineral density (aBMD) of lumbar sacral spine | Areal bone mineral density of lumbar sacral spine determined by DXA | Measured once at one study visit | 
| Trabecular bone score of LS spine | Trabecular bone score of lumbar sacral (LS) spine determined by DXA | Measured once at one study visit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Acromegaly, Pegvisomant, Osteoporosis