title: Bone turnover in passive smoking female rat: relationships to change in bone mineral density.
abstract: BACKGROUND
  Many studies have identified smoking as a risk factor for osteoporosis, but it is unclear whether passive smoking has an effect on bone mineral density and bone turnover and if such an effect could cause osteoporosis.The purpose of the study was to investigate the effect of passive smoking on bone mineral density (BMD) and bone turnover and the relationship between BMD and bone turnover in female rat.
  
  
  METHODS
  Forty-eight female Wistar rats were randomized into six groups: 2-month, 3-month,4-month smoke-exposed rats and their controls. A rat model of passive cigarette smoking was prepared by breeding female rats in a cigarette-smoking box for 2, 3 or 4 months. Serums were analyzed for levels of osteocalcin, bone-specific alkaline phosphatase (b-ALP) and Tartrate-resistant acid phosphatase 5b (TRACP 5b). BMD was assessed at lumbar vertebrae and femur by dual energy X-ray absorptiometry in passive smoking rats and in control rats.
  
  
  RESULTS
  BMD of lumbar spine and femur was lower in 4-month smoke-exposed female rats than that in controls. However, there was no significant difference in serum osteocalcin levels between smoke-exposed rats and controls. Significantly lower b-ALP and higher TRACP 5b were found in the 3-month or 4-month smoke-exposed rats compared to controls. Subsequent analysis showed that b-ALP positively correlated with BMD of the lumbar vertebrae(r = 0.764, P = 0.027) and femur(r = 0.899, P = 0.002) in 4-month smoke-exposed female rats. Furthermore, TRACP 5b levels negatively correlated with BMD of lumbar vertebrae (r = -0.871, P = 0.005) and femur (r = -0.715, P = 0.046) in 4-month smoke-exposed female rats.
  
  
  CONCLUSIONS
  Our data suggest that smoke exposure can inhibit bone formation and increase bone resorption. The hazardous effects of passive smoking on bone status are associated with increased bone turnover in female rat.
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Shu-guang
authors.initials: SG
authors.lastname: Gao
authors.forename: Kang-hua
authors.initials: KH
authors.lastname: Li
authors.forename: Mai
authors.initials: M
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Hong
authors.initials: H
authors.lastname: Shen
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Wen-shuo
authors.initials: WS
authors.lastname: Xu
authors.forename: Jian
authors.initials: J
authors.lastname: Tian
authors.forename: Guang-hua
authors.initials: GH
authors.lastname: Lei
mesh_terms: D015502:Absorptiometry, Photon; D000135:Acid Phosphatase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D000704:Analysis of Variance; D000818:Animals; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D016723:Bone Remodeling; D001862:Bone Resorption / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D007527:Isoenzymes / Q000097:blood; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D009538:Nicotine / Q000097:blood; D015675:Osteocalcin / Q000097:blood; D010024:Osteoporosis / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012907:Smoking / Q000009:adverse effects*; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D014028:Tobacco Smoke Pollution; D015675:Osteocalcin; D009538:Nicotine; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase