Poster Presentation ESA-SRB-APEG-NZSE 2022

Growing weaker: a case report of the under-recognised complication of vertebral fractures in acromegaly (#351)

Brian Tran 1 2 , Matthew Luttrell 1 3
  1. Department of Endocrinology, Nepean Hospital, Sydney, New South Wales, Australia
  2. Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
  3. Bathurst Hospital, Bathurst, New South Wales, Australia

Acromegaly is a slowly progressive condition of excess growth hormone (GH) production resulting in the abnormal enlargement of bones and thickening of soft tissues of the body. Osteoporosis is known to be associated with GH deficiency but can also occur in GH excess, manifesting predominantly as fragility vertebral fractures (VFs).

A 32-year-old male was referred for assessment of a minimal trauma T7 VF. A DEXA scan showed lumbar spine osteopaenia (BMD 0.988g/cm2, T-score -1.9SD) with normal bone density in both hips (mean BMD 1.264g/cm2, mean T-score +1.3SD). Incidentally, testosterone was low (9.9nmol/L [11.5-32.0]) with inappropriately low FSH and LH, though these normalised pre-operatively without intervention. Clinically, there was large sweaty spade-like hands and mild prognathism, but no other features consistent with active acromegaly. There was no significant past medical, family or medication history.

Further investigations revealed IGF-1 72-83nmol/L (14-41) with failure of suppression with an GH suppression test. An MRI pituitary identified an 8x4mm superior pituitary abnormality displacing the pituitary stalk. He underwent a transsphenoidal sinus hypophysectomy 10 months following his initial presentation, experiencing post-operative complications of both diabetes insipidus and syndrome of inappropriate anti-diuretic hormone at different times.

Subsequent follow up demonstrated resolution of GH excess with normalisation of GH and IGF-1 levels. He was commenced on oral bisphosphonates for osteoporosis and his bone mineral density has remained stable on repeat DEXAs, with no signs or symptoms of active acromegaly.

This case demonstrates that fragility VFs can be the sole presenting complaint in patients with osteoporosis due to underlying acromegaly. GH and IGF-1 excess contributes to increased bone turnover with detrimental effects on cortical and trabecular bone structure1. VFs have been reported in up to 60% of acromegalic patients2 with male predominance1. It is associated with duration of active disease3 with no direct correlation between VFs and BMD1.

  1. Giustina A. Acromegaly and vertebral fractures: Facts and questions. Trends in Endocrinology & Metabolism. 2020;31(4):274–5.
  2. Mazziotti G, Bianchi A, Bonadonna S, Cimino V, Patelli I, Fusco A, et al. Prevalence of vertebral fractures in men with acromegaly. The Journal of Clinical Endocrinology & Metabolism. 2008;93(12):4649–55.
  3. Mazziotti G, Biagioli E, Maffezzoni F, Spinello M, Serra V, Maroldi R, et al. Bone turnover, bone mineral density, and fracture risk in acromegaly: A meta-analysis. The Journal of Clinical Endocrinology & Metabolism. 2015;100(2):384–94.