title: Bone material strength index as measured by impact microindentation is altered in patients with acromegaly.
abstract: OBJECTIVE
  Acromegaly is a rare disease caused by excess growth hormone (GH) production by the pituitary adenoma. The skeletal complications of GH and IGF-1 excess include increased bone turnover, increased cortical bone mass and deteriorated microarchitecture of trabecular bone, associated with a high risk of vertebral fractures in the presence of relatively normal bone mineral density (BMD). We aimed to evaluate tissue-level properties of bone using impact microindentation (IMI) in well-controlled patients with acromegaly aged ≥18 years compared to 44 controls from the outpatient clinic of the Centre for Bone Quality.
  
  
  METHODS
  In this cross-sectional study, bone material strength index (BMSi) was measured in 48 acromegaly patients and 44 controls with impact microindentation using the osteoprobe.
  
  
  RESULTS
  Mean age of acromegaly patients (54% male) was 60.2 years (range 37.9-76.5), and 60.5 years (range 39.8-78.6) in controls (50% male). Patients with acromegaly and control patients had comparable BMI (28.2 kg/m2± 4.7 vs 26.6 kg/m2± 4.3, P = 0.087) and comparable BMD at the lumbar spine (1.04 g/cm2± 0.21 vs 1.03 g/cm2± 0.13, P = 0.850) and at the femoral neck (0.84 g/cm2± 0.16 vs 0.80 g/cm2± 0.09, P = 0.246). BMSi was significantly lower in acromegaly patients than that in controls (79.4 ± 0.7 vs 83.2 ± 0.7; P < 0.001).
  
  
  CONCLUSIONS
  Our data indicates that tissue-level properties of cortical bone are significantly altered in patients with controlled acromegaly after reversal of long-term exposure to pathologically high GH and IGF-1 levels. Our findings also suggest that methods other than DXA should be considered to evaluate bone fragility in patients with acromegaly.
authors.affiliation: Centre for Bone Quality, Division Endocrinology.
authors.forename: F
authors.initials: F
authors.lastname: Malgo
authors.affiliation: Centre for Bone Quality, Division Endocrinology.
authors.forename: N A T
authors.initials: NAT
authors.lastname: Hamdy
authors.affiliation: Centre for Bone Quality, Division Nephrology.
authors.forename: T J
authors.initials: TJ
authors.lastname: Rabelink
authors.affiliation: Centre for Bone Quality, Department of Radiology.
authors.forename: H M
authors.initials: HM
authors.lastname: Kroon
authors.affiliation: Centre for Bone QualityCentre for Endocrine Tumours Leiden, Department of Medicine, Division Endocrinology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: K M J A
authors.initials: KMJA
authors.lastname: Claessen
authors.affiliation: Centre for Bone QualityCentre for Endocrine Tumours Leiden, Department of Medicine, Division Endocrinology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: A M
authors.initials: AM
authors.lastname: Pereira
authors.affiliation: Centre for Bone QualityCentre for Endocrine Tumours Leiden, Department of Medicine, Division Endocrinology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: N R
authors.initials: NR
authors.lastname: Biermasz
authors.affiliation: Centre for Bone Quality, Division Endocrinology.
authors.forename: N M
authors.initials: NM
authors.lastname: Appelman-Dijkstra
mesh_terms: D000172:Acromegaly / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D015519:Bone Density; D016723:Bone Remodeling; D003430:Cross-Sectional Studies; D005260:Female; D005272:Femur Neck; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged
chemical_list: D007334:Insulin-Like Growth Factor I