title: Relationship between bone mineral density, weight, and estrogen levels in pre and postmenopausal women.
abstract: Bone loss in postmenopausal women is mainly due to estrogen deficiency affecting the balance between osteoclast resorption and bone formation controlled by osteoblasts.
  
  
  OBJECTIVE
  To determine the relationship between bone mineral density (BMD) in pre and postmenopausal Caucasian women, and estrogen levels.
  
  
  METHODS
  Cross-sectional study including six groups of 8 to 15 pre- and postmenopausal healthy volunteers with different weights, body mass index (BMI) (normal or underweight < 25 kg/m2, overweight 25-30 kg/m2, and obese > 30 kg/m2), not exposed to antiosteoporotic therapy. Lumbar bone mineral density (BMD) and body composition (BC) were evaluated by dual X ray absorptiometry (DXA, Hologic), while serum estradiol and estrone were measured by ELISA.
  
  
  RESULTS
  BMD in postmenopausal women is lower than in premenopausal women irrespective of body weight (p<0.05). Estradiol and estrone are positively correlate with bone mass in premenopausal women, but not in postmenopausal women (R2 0.3209, R2 0.2579, respectively).
  
  
  CONCLUSIONS
  It is very important to identify the risk factors for osteoporosis, especially in postmenopausal women, as we will show that aromatization of androgens into estrogens in adipose tissue appears not to have a significant role in postmenopausal women bone protection. Key-
authors.affiliation: University of Medicine and Pharmacy Grigore T Popa Iasi, Faculty of Medicine.
authors.forename: Morcov
authors.initials: M
authors.lastname: Corina
authors.forename: Carmen
authors.initials: C
authors.lastname: Vulpoi
authors.forename: D
authors.initials: D
authors.lastname: Brănişteanu
mesh_terms: D015502:Absorptiometry, Photon; D015415:Biomarkers / Q000097:blood; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D015519:Bone Density; D003430:Cross-Sectional Studies; D004967:Estrogens / Q000097:blood*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D050177:Overweight / Q000150:complications; D017698:Postmenopause; D017697:Premenopause; D015995:Prevalence; D012307:Risk Factors; D012383:Romania / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D004967:Estrogens