Intraindividual variability in bone markers in the urine

Abstract

The biological variability of urinary bone resorption markers was measured in 30 healthy and 20 postmenopausal osteoporotic women. The second spot urines were collected at weekly intervals for 5 weeks and urinary pyridinium crosslinks, hydroxyproline, calcium and Ntx were evaluated. Results are discussed in relation to analytical variability, critical difference values and index of individuality. In conclusion monitoring and classifying bone turnover in groups of persons are well established, but the routine use of urinary biochemical bone markers in the individual patient is of limited use.

Key Words:

• Biological variability
• urinary bone markers, critical differences
• index of individuality