title: Implications of combined ovariectomy/multi-deficiency diet on rat bone with age-related variation in bone parameters and bone loss at multiple skeletal sites by DEXA.
abstract: BACKGROUND
  Osteoporosis is a multi-factorial, chronic, skeletal disease highly prevalent in post-menopausal women and is influenced by hormonal and dietary factors. Because animal models are imperative for disease diagnostics, the present study establishes and evaluates enhanced osteoporosis obtained through combined ovariectomy and deficient diet by DEXA (dual-energy X-ray absorptiometry) for a prolonged time period.
  
  
  METHODS
  Sprague-Dawley rats were randomly divided into sham (laparotomized) and OVX-diet (ovariectomized and fed with deficient diet) groups. Different skeletal sites were scanned by DEXA at the following time points: M0 (baseline), M12 (12 months post-surgery), and M14 (14 months post-surgery). Parameters analyzed included BMD (bone mineral density), BMC (bone mineral content), bone area, and fat (%). Regression analysis was performed to determine the interrelationships between BMC, BMD, and bone area from M0 to M14.
  
  
  RESULTS
  BMD and BMC were significantly lower in OVX-diet rats at M12 and M14 compared to sham rats. The Z-scores were below -5 in OVX-diet rats at M12, but still decreased at M14 in OVX-diet rats. Bone area and percent fat were significantly lower in OVX-diet rats at M14 compared to sham rats. The regression coefficients for BMD vs. bone area, BMC vs. bone area, and BMC vs. BMD of OVX-diet rats increased with time. This is explained by differential percent change in BMD, BMC, and bone area with respect to time and disease progression.
  
  
  CONCLUSIONS
  Combined ovariectomy and deficient diet in rats caused significant reduction of BMD, BMC, and bone area, with nearly 40% bone loss after 14 months, indicating the development of severe osteoporosis. An increasing regression coefficient of BMD vs. bone area with disease progression emphasizes bone area as an important parameter, along with BMD and BMC, for prediction of fracture risk.
authors: Laboratory of Experimental Trauma Surgery, Justus-Liebig University, Department of Trauma Surgery, University Hospital of Giessen-Marburg, Giessen, Germany.
authors: Parameswari
authors: P
authors: Govindarajan
authors: Gudrun
authors: G
authors: Schlewitz
authors: Nathalie
authors: N
authors: Schliefke
authors: David
authors: D
authors: Weisweiler
authors: Volker
authors: V
authors: Alt
authors: Ulrich
authors: U
authors: Thormann
authors: Katrin Susanne
authors: KS
authors: Lips
authors: Sabine
authors: S
authors: Wenisch
authors: Alexander C
authors: AC
authors: Langheinrich
authors: Daniel
authors: D
authors: Zahner
authors: Nasr Y
authors: NY
authors: Hemdan
authors: Wolfgang
authors: W
authors: Böcker
authors: Reinhard
authors: R
authors: Schnettler
authors: Christian
authors: C
authors: Heiss
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D001835:Body Weight; D001842:Bone and Bones / Q000503:physiopathology*; D004032:Diet; D004195:Disease Models, Animal; D005260:Female; D050723:Fractures, Bone / Q000503:physiopathology; D006801:Humans; D044342:Malnutrition / Q000000981:diagnostic imaging*; D015233:Models, Statistical; D010024:Osteoporosis / Q000175:diagnosis* / Q000503:physiopathology*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors