title: Age-related changes of serum tartrate-resistant acid phosphatase 5b and the relationship with bone mineral density in Chinese women.
abstract: OBJECTIVE
  Osteoclastic activity is mainly assessed by measurement of urinary markers (eg C-terminal cross-linked telopeptides of type I collagen, N-terminal crosslinked telopeptides of type I collagen, etc), the levels of which could often be affected by renal clearance. Recently, serum tartrate-resistant acid phosphatase 5b (TRACP5b) has been used as an alternative serum marker to evaluate osteoclastic activity. We investigated the age-related changes of TRACP5b level and its association with bone mineral density (BMD) in Chinese women.
  
  
  METHODS
  Seven-hundred and twenty-two Chinese mainland women aged 20-79 years were recruited in the study. Serum TRACP5b level was measured using immunoassay to evaluate the state of bone resorption. Bone mineral density (BMD) (g/cm2) at lumbar spine 1-4 and proximal femur were measured by duelenergy X-ray absorptiometry.
  
  
  RESULTS
  The serum TRACP5b level reached a bottom value in premenopausal women aged 30-39, gradually increased in women aged 40-49, rapidly rose in women aged 50-59, and culminated with a maximum value in women aged 60-69 before a slow drop in women aged 70- 79. The average level of TRACP5b was significantly higher in postmenopausal women [(3.29+/-1.07) U/L] than in premenopausal women ([1.70+/-0.59] U/L). The levels of TRACP5b were inversely correlated with BMD at all measured sites (P<0.001). Furthermore, the level of TRACP5b was obviously higher in women with osteoporosis and osteopenia than those with normal bone mass (P<0.001).
  
  
  CONCLUSIONS
  We have established the reference values of serum TRACP5b in Chinese mainland women, and found that postmenopausal women had higher TRACP5b concentration than younger women. The results showed that serum TRACP5b was a sensitive and useful parameter for the evaluation of age-related changes of bone absorption.
authors.affiliation: The Department of Osteoporosis, Osteoporosis Research Unit, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China.
authors.forename: Yue-juan
authors.initials: YJ
authors.lastname: Qin
authors.forename: Zhen-lin
authors.initials: ZL
authors.lastname: Zhang
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Wei-wei
authors.initials: WW
authors.lastname: Hu
authors.forename: Yu-juan
authors.initials: YJ
authors.lastname: Liu
authors.forename: Yun-qiu
authors.initials: YQ
authors.lastname: Hu
authors.forename: Miao
authors.initials: M
authors.lastname: Li
authors.forename: Jie-mei
authors.initials: JM
authors.lastname: Gu
authors.forename: Jin-wei
authors.initials: JW
authors.lastname: He
mesh_terms: D015502:Absorptiometry, Photon; D000135:Acid Phosphatase / Q000097:blood*; D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000097:blood; D001862:Bone Resorption / Q000378:metabolism; D002681:China; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000175:diagnosis; D017698:Postmenopause / Q000097:blood; D000071681:Tartrate-Resistant Acid Phosphatase; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase