Abstract
Diurnal variations in the excretion of bone resorption markers were assessed in order to identify the type of urine collection which provides the most information on bone resorption rate and its relation to measuring bone dynamics in a postmenopausal population. Sixty women, ages 43–67 and without disease or treatment known to affect bone mineral density, were divided into two groups on the basis of femoral mineral density T‐score: <1.5 (Group I), >1.5 (Group II). Bone formation was assessed by measuring bone alkaline phosphatase activity and osteocalcin concentration, bone resorption by urinary hydroxyproline, pyridinoline and deoxypiridinoline, N‐telopeptide, galactosyl hydroxylysine, and CrossLaps. To identify the more appropriate collection times, urine samples were collected from 7 am to 3 pm; from 3 pm to 11 pm; from 11 pm to 7 am. Twenty‐four hour urine collection and first morning void urine samples were also measured.
The findings suggest that nocturnal collection and first morning void samples provide the most reliable data on the rate of bone degradation, possibly showing bone loss not only in osteopenic patients but also in women with a low T‐score. Nocturnal and first morning samples should therefore be recommended in order to standardize sample collection, as they enable an accurate assessment of bone resorption markers and improved comparability to results from different studies, as well as a less cumbersome collection modality. J. Clin. Lab. Anal. 12:145–149, 1998. © 1998 Wiley‐Liss, Inc.
Keywords: bone alkaline phosphatase, osteocalcin, hydroxyproline, pyridinoline, deoxypiridinoline, N‐telopeptide, galactosyl hydroxylysine, CrossLaps
References
- 1. Taylor AK, Lueken SA, Libanati C, Baylink DJ: Biochemical markers of bone turnover for the clinical assessment of bone metabolism. Rheum Dis Clin North Am 20: 589–607, 1994. [PubMed] [Google Scholar]
- 2. Risteli L, Risteli J: Biochemical markers of bone metabolism. Ann Med 25: 385–93, 1993. [DOI] [PubMed] [Google Scholar]
- 3. McGowan JA: Osteoporosis: Assessment of bone loss and remodeling. Aging Clin Exp Res 5: 81–93, 1993. [DOI] [PubMed] [Google Scholar]
- 4. Price CP, Thompson PW: The role of biochemical tests in the screening and monitoring of osteoporosis. Ann Clin Biochem 32: 244–60, 1995. [DOI] [PubMed] [Google Scholar]
- 5. Panteghini M, Pagani F: Biological variation in urinary excretion of pyridinium crosslinks: Recommendations for the optimum specimen. Ann Clin Biochem 33: 36–42, 1996. [DOI] [PubMed] [Google Scholar]
- 6. Eastell R, Robins SP, Colwell T, Assiri AMA, Riggs BL, Russell RGG: Evaluation of bone turnover in type‐I osteoporosis using biochemical markers specific for both bone formation and bone resorption. Osteoporos Int 3: 255–260, 1993. [DOI] [PubMed] [Google Scholar]
- 7. Garnero P, Shih WJ, Gineyts E, Karpf DB, Delmas PD: Comparison of new biochemical markers of bone turnover in late postmenopausal osteoporotic women in response to alendronate treatment. J Clin Endocrinol Metab 79: 1693–1700, 1994. [DOI] [PubMed] [Google Scholar]
- 8. Gertz BJ, Shao P, Hanson DA, et al.: Monitoring bone resorption in early postmenopausal women by an immunoassay for cross‐linked collagen peptides in urine. J Bone Miner Res 9: 135–142, 1994. [DOI] [PubMed] [Google Scholar]
- 9. Bonde M, Qvist P, Fledelius C, Riis BJ, Christiansen C: Immunoassay for quantifying type‐I collagen degradation products in urine evaluated. Clin Chem 40: 2022–25, 1994. [PubMed] [Google Scholar]
- 10. Gardner HJ, Gardner SB, Winter PD: Confidence interval analysis microcomputer program. Br Med J. 77, 1989. [Google Scholar]