Endocrine Abstracts

Objective: Arthropathy is the commonest morbidity in acromegaly and the main determinant of quality of life in these patients. Most of current knowledge is derived from studies using conventional x-rays. This study aims to characterise acromegalic arthropathy using modern imaging techniques.

Methods: Case control study comprising of 60 acromegaly patients (29 males, mean age 54.8± 12.9yrs) and 300 age/gender-matched controls from the publicly available Osteoarthritis Initiative (OAI) database. Bilateral knee MRI scans were obtained. Knee bone shape, joint space width (JSW) and cartilage thickness were measured based on automated segmentation of MR images of knee bones and calculation of bone area using active appearance models.

Results: Acromegaly patients had increased medial JSW compared with controls [6.21mm (95% CI 6.03-6.40) vs. 5.78mm (95% CI 5.70-5.87), P < 0.001] and increased lateral and medial femorotibial cartilage thickness. Patella and medial tibia bone areas were also increased in acromegaly patients. B-score (a biomarker associated with severity and risk of progression of osteoarthritis) was significantly higher in patients than controls [1.7 (95% CI 1.32-2.08) vs. 1.01 (0.84-1.18), P = 0 .001]. Twenty-one acromegaly patients (35%) had B-score ≥2, which is indicative of osteoarthritis. These patients had higher GH levels at diagnosis of acromegaly and required higher number of therapeutic interventions compared with patients with B-score <2 (n = 39). Additionally, patients with B-score ≥2 had significantly larger femoral, tibial and patella bone areas, increased medial JSW and lateral and medial femorotibial cartilage thickness compared with the remaining patients.

Conclusions: Acromegaly patients despite higher B-score and larger bone area have preserved and/or increased JSW due to increased cartilage thickness. The higher pre-treatment GH values and higher number of therapeutic interventions seen in patients with B-score ≥2, indicate that exposure to excessive GH is a risk factor for more pronounced changes to knee bone shape and potentially more severe arthropathy.