Effects of Parathyroid Hormone and Alendronate Alone or in Combination in Osteoporosis

Abstract

Both Black et al.¹ and Finkelstein et al.² (Sept. 25 issue) measured markers of bone turnover, but neither group took osteoprotegerin into consideration as a possibly relevant player in bone remodeling. Osteoprotegerin, a secreted member of the family of tumor necrosis factor receptors, is a potent inhibitor of osteoclast activation and differentiation.^3,4 In patients with osteoporosis, osteoprotegerin has been found to correlate strongly with markers of bone turnover⁵ — a finding that may point toward a higher level of osteoprotegerin expression in patients with a higher level of these markers.