Which marker can help assess the rate of bone resorption?

Which marker can help assess the rate of bone resorption?

• A. Free pyridinoline (Pyr)
• B. Serum type 1 collagen
• C. Serum osteocalcin
• D. Serum alkaline phosphatase

Answer: (A)

Free pyridinoline is a cross-linking molecule that is released during the breakdown of type I collagen, which is a major component of bone matrix. When bone resorption occurs, the matrix is degraded, releasing these cross-links into the bloodstream. Thus, measuring the levels of free pyridinoline can provide insight into the rate of bone resorption, making it a valuable biomarker in evaluating bone physiology and disease processes such as osteoporosis. In contrast, serum type 1 collagen and serum osteocalcin are more related to bone formation rather than resorption. Type 1 collagen levels indicate the amount of new bone being formed, while osteocalcin is a hormone produced by osteoblasts, reflective of the activity and function of these bone-forming cells. Serum alkaline phosphatase can also be elevated in conditions of bone formation or remodeling, but it does not specifically represent bone resorption. Therefore, free pyridinoline is the most direct and relevant marker among the options provided for assessing bone resorption rates.

Free pyridinoline is a cross-linking molecule that is released during the breakdown of type I collagen, which is a major component of bone matrix. When bone resorption occurs, the matrix is degraded, releasing these cross-links into the bloodstream. Thus, measuring the levels of free pyridinoline can provide insight into the rate of bone resorption, making it a valuable biomarker in evaluating bone physiology and disease processes such as osteoporosis.

In contrast, serum type 1 collagen and serum osteocalcin are more related to bone formation rather than resorption. Type 1 collagen levels indicate the amount of new bone being formed, while osteocalcin is a hormone produced by osteoblasts, reflective of the activity and function of these bone-forming cells. Serum alkaline phosphatase can also be elevated in conditions of bone formation or remodeling, but it does not specifically represent bone resorption. Therefore, free pyridinoline is the most direct and relevant marker among the options provided for assessing bone resorption rates.