Calcium and bone turnover markers in acromegaly: a prospective controlled study.

Calcium and bone turnover markers in acromegaly: a prospective controlled study.

J Clin Endocrinol Metab. 2017 Apr 12;:

Authors: Constantin T, Tangpricha V, Shah R, Oyesiku NM, Ioachimescu OC, Ritchie J, Ioachimescu AG

Abstract
Context: Acromegaly has been associated with calcium-phosphate and bone turnover alterations. Controlled studies of these interactions are sparse.
Objective: To evaluate calcium and bone metabolism in active and treated acromegaly. Design/Setting/Patients: We conducted a controlled prospective study at a tertiary referral center. We studied 22 patients with acromegaly referred for surgical or medical therapy (ACM) and 22 with nonfunctioning pituitary adenomas referred for surgery (control).
Main outcome measures: Calcium (serum and urine), phosphorus, PTH, 25-hydroxy- and 1,25-dihydroxy-vitamin D, bone turnover markers (serum C-terminal telopeptide type 1 collagen (CTX) and Procollagen type 1 N-terminal propeptide, (P1NP)), and cytokines (RANK-L and osteoprotegerin) at baseline and 3-6 months after treatment.
Results: At baseline, the ACM group had lower PTH levels than controls (36.3±13.9 vs 56.0±19.9 pg/ml) and higher phosphorus (4.34±0.71 vs 3.55±0.50 mg/dL) (p<0.01). Groups had similar levels of serum and urine calcium, 25-hydroxy- and 1,25-dihydroxy-vitamin D. The ACM group had higher bone turnover markers than control; P1NP and CTX were strongly correlated (R2 0.82, P<0.05). CTX was dependent on age and disease group, but not on gender or gonadal status. After treatment of acromegaly, serum calcium (9.52±0.43 to 9.26±0.28 mg/dL), phosphorus (4.34±0.71 to 3.90±0.80 mg/dL) and CTX (0.91±0.75 to 0.63±0.68 ng/ml) decreased, while PTH increased (36.3±13.9 to 48.9±16.7 pg/ml) (p 0.01). 25-hydroxyvitamin D, P1NP and RANK-L/ osteoprotegerin ratio did not change significantly.
Conclusion: Acromegaly patients exhibited PTH-independent calcium-phosphate alterations and enhanced coupled bone formation and resorption. Within 6 months of treatment, bone resorption decreased, while RANK-L/osteoprotegerin changes were inconsistent.

PMID: 28407138 [PubMed - as supplied by publisher]

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