A 30 year old female with a 15 year history of asthma presents to the emergency room with left elbow pain. Physical examination reveals tenderness and swelling over the olecranon process. An x-ray of the left arm reveals a fracture. Her medications include oral prednisone and albuterol aerosol. By which of the following mechanisms might coicosteroids have contributed to her fracture?
Coicosteroids inhibit the proliferation and function of osteoblasts, which are modified mesenchymal cells. These agents stimulate osteoclasts to differentiate from bone marrow macrophages and also stimulate their activity.The net effect is maximal bone loss with increased resorption and decreased formation. Ref: Funder J.W. (2011). Chapter 42. ACTH, Adrenal Steroids, and Pharmacology of the Adrenal Coex. In B.C. Knollmann (Ed), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.
Decreased osteoblastic bone formation only
Decreased osteoblastic bone formation and osteoclastic bone resorption
Increased osteoclastic bone resorption only
Increased osteoclastic bone resorption and decreased osteoblastic bone formation