Cholecalciferol use is associated with a decreased risk of incident morphometric vertebral fractures in acromegaly

Introduction: Skeletal fragility is observed in 30-60% of acromegaly patients, representing an emerging complication of the disease that increases disability. Despite several studies have investigated the clinical and hormonal prognostic factors for the occurrence of vertebral fractures (VFs) in acromegaly, very few data are available on their prevention/treatment including the effect of vitamin D (VD) supplementation, which has been reported to have a protective effect in some studies in patients with osteoporosis. We aimed to investigate the role of cholecalciferol (D3) supplementation in the prevention of incident VFs (i-VF) in acromegaly. Patients and methods: A longitudinal, retrospective and multicenter study was performed on 61 acromegaly patients treated and untreated with D3 supplementation. Results: Twenty-six patients were treated with D3 supplementation according to clinical guidelines. The median D3 weekly dosage was 8500 IU (IQR: 3900). The median duration of D3 supplementation was 94 months (IQR: 38). At last follow-up, i-VFs were diagnosed in 14 patients (23%). I-VFs were less prevalent in patients on D3 supplementation (14.3% of cases), with respect to patients not treated with D3 (85.7%; p = 0.02). The final level of serum V25OH-D was significantly lower in patients who developed i-VFs (28.6 ng/mL, IQR: 4.1) as compared to patients who did not develop i-VFs (34.2 ng/mL, IQR: 9.6; p = 0.05). The logistic regression confirmed the protective role of D3 supplementation on the occurrence of i-VFs (OR: 0.16 95%IC: 0.03-0.79; p = 0.01). Conclusion: It is likely that D3 supplementation could lead to a reduction in i-VFs, in acromegaly.