The effect of glucocorticoids on Thrombospondin-1, Osteocalcin and the Thrombospondin-1:Osteocalcin ratio in humans.
Clin Endocrinol (Oxf) 2019;
91:728-736. [PMID:
31612515 DOI:
10.1111/cen.14108]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/10/2019] [Accepted: 10/13/2019] [Indexed: 01/25/2023]
Abstract
OBJECTIVE
Thrombospondin-1 (TSP1), a matricellular protein, and Osteocalcin (OCN), a noncollagenous protein secreted by osteoblasts, are known to be up- and down-regulated, respectively, by glucocorticoids. The aim of this study was to determine whether a ratio between TSP1:OCN was altered by changes in glucocorticoid activity in humans.
DESIGN
Prospective observational study.
SETTING
Tertiary university hospital in Queensland, Australia.
PATIENTS AND MEASUREMENTS
Patients with Cushing's syndrome (CS, n = 19), asthma or giant cell arteritis on chronic prednisolone treatment (PRED, n = 13), adrenal insufficiency (AI, n = 16) and healthy volunteers (HV, n = 20). Plasma TSP1 and serum total OCN were measured by immunoassay at 0800h, 1200h and 1600h in patients with CS, patients with AI taking replacement glucocorticoids, HV before and after 4 mg dexamethasone and PRED patients predose at 800 and 4 hours post-dose at 1200 hours.
RESULTS
Plasma TSP1 in CS was higher (P < .0001), and serum OCN was lower (P < .0001) than HV. The TSP1:OCN ratio in HV increased significantly after 4 mg dexamethasone (P < .0001) and in AI after taking their hydrocortisone replacement therapy (P < .001). PRED patients had a higher TSP1:OCN ratio compared with HV at both 800 and 1200 hours (both P < .001), but no significant change occurred from pre- to post-dose. A TSP1:OCN ratio of >73 at 800 hours differentiated CS from HV with a sensitivity of 95% and a specificity of 100%.
CONCLUSIONS
The TSP1:OCN ratio is elevated in patients on prednisolone and in patients with CS compared with healthy volunteers. It may be a useful biomarker of total body glucocorticoid activity in humans.
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