Câu 30: USMLE: United States Medical Licensing Examination

A 62-year-old woman comes to the physician because of low back pain for 1 week. Menopause occurred 10 years ago. Physical examination shows localized tenderness over the lumbar spine after movement. X-rays of the spine show a compression fracture of L1-2. A DEXA scan shows decreased bone mineral density. Serum calcium and phosphorus concentrations and serum alkaline phosphatase activity are within the reference ranges. A bisphosphonate drug is prescribed. The expected beneficial effect of this drug is most likely due to which of the following actions?

1. A. Decreased insulin-like growth factor-1 concentration
2. B. Decreased osteoclast activity — đáp án hiện tại
3. C. Decreased osteoprotegerin production
4. D. Increased 1, 25- dihydroxycholecalciferol concentration
5. E. Increased osteoblast actitvity
6. F. Increased receptor activator of NF-kB ligand (RANKL) production