title: Eldecalcitol, a vitamin D analog, reduces bone turnover and increases trabecular and cortical bone mass, density, and strength in ovariectomized cynomolgus monkeys.
abstract: Vitamin D insufficiency is common in elderly people worldwide, and intake of supplementary calcium and vitamin D is recommended to those with a high risk of fracture. Several clinical studies and meta-analyses have shown that calcium and vitamin D supplementation reduces osteoporotic fractures, and a strong correlation exists between vitamin D status and fracture risk. Vitamin D supplementations improve calcium balance in the body; however, it remains unclear whether vitamin D directly affects bone metabolism. Recently, eldecalcitol (ELD), an active form of vitamin D analog, has been approved for the treatment of osteoporosis in Japan. A 3-year clinical trial showed ELD treatment increased lumbar spine bone mineral density (BMD) and reduced fracture risk in patients with osteoporosis. To evaluate the mechanism of ELD action in bone remodeling, ovariectomized cynomolgus monkeys were treated with 0.1 or 0.3μg/day of ELD for 6months. This treatment increased lumbar BMD by 4.4% and 10.2%, respectively, and suppressed ovariectomy-induced increases in bone turnover markers compared to OVX-vehicle control. Histomorphometric analysis of bone revealed that both bone formation parameters and bone resorption parameters in the trabecular bone of the lumbar vertebrae were suppressed by ELD treatment. ELD treatment also improved biomechanical properties of the lumbar vertebrae and the femoral neck in the ovariectomized cynomolgus monkeys. These results indicate that, in a bone-remodeling animal model, ELD increases BMD and improves bone biomechanical properties by normalizing bone turnover. Therefore, ELD has a direct and potentially beneficial effect on bone metabolism.
authors.affiliation: Bone Research, Charles River Laboratories Preclinical Services Montreal, Senneville, Quebec H9X 3R3, Canada.
authors.forename: Susan Y
authors.initials: SY
authors.lastname: Smith
authors.forename: Nancy
authors.initials: N
authors.lastname: Doyle
authors.forename: Marilyne
authors.initials: M
authors.lastname: Boyer
authors.forename: Luc
authors.initials: L
authors.lastname: Chouinard
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Saito
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects; D001862:Bone Resorption; D001842:Bone and Bones / Q000187:drug effects*; D005260:Female; D008252:Macaca fascicularis; D010012:Osteogenesis / Q000187:drug effects*; D010052:Ovariectomy; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D014807:Vitamin D; C547512:eldecalcitol
keywords: Bone histomorphometry; Bone marker; Bone mineral density; Bone strength; Osteoporosis; Vitamin D