INTRAINDIVIDUAL VARIABILITY IN BONE MARKERS IN THE URINE

The biological variability of urinary bone resorption markers was meas ured in 30 healthy and 20 postmenopausal osteoporotic women. The secon d spot urines were collected at weekly intervals for 5 weeks and urina ry pyridinium crosslinks, hydroxyproline, calcium and Ntx were evaluat ed. Results are discussed in relation to analytical variability, criti cal difference values and index of individuality. In conclusion monito ring and classifying bone turnover in groups of persons are well estab lished, but the routine use of urinary biochemical bone markers in the individual patient is of limited use.