title: Endogenous hormones, muscle strength, and risk of fall-related fractures in older women.
abstract: BACKGROUND
  Among older people, fracture-causing fall often leads to health deterioration. The role of endogenous hormone status and muscle strength on fall-related fracture risk is unclear. This study investigates if, after adjustment for bone density, endogenous hormones and muscle strength would predict fall-related limb fracture incidence in older community-dwelling women followed-up over 10 years.
  
  
  METHODS
  As a part of a prospective population-based study, 187 75-year-old women were investigated. Serum estradiol, testosterone, sex hormone binding globulin, and dehydroepiandrosterone sulfate concentrations were analyzed, and isometric muscle strength and bone mineral density were assessed. Fall-related limb fractures were gathered from patient records.
  
  
  RESULTS
  Serum estradiol concentration was a significant predictor of fall-related limb fractures. Women with serum estradiol concentrations less than 0.022 nmol/L had a 3-fold risk (relative risk 3.05; 95% confidence interval, 1.26-7.36), and women with estradiol concentrations between 0.022 and 0.066 nmol/L doubled the risk (relative risk 2.24; 95% confidence interval, 0.97-5.19) of fall-related limb fracture compared to the women with estradiol concentrations ()above 0.066 nmol/L. Adjustment for muscle strength and bone mineral density did not materially change the risk estimates. High muscle strength was associated with a low incidence of fall-related limb fractures.
  
  
  CONCLUSIONS
  This study showed that in 75-year-old women higher serum estradiol concentration and greater muscle strength were independently associated with a low incidence of fall-related limb fractures even after adjustment for bone density. Our results suggest that hormonal status and muscle strength have their own separate mechanisms protecting from fall-related fractures. This finding is of importance in developing preventive strategies, but calls for further study.
authors.affiliation: Department of Health Sciences, University of Jyväskylä, P.O. Box 35 (Viv), FIN-40014 Jyväskylä, Finland. sipila@sport.jyu.fi
authors.forename: Sarianna
authors.initials: S
authors.lastname: Sipilä
authors.forename: Eino
authors.initials: E
authors.lastname: Heikkinen
authors.forename: Sulin
authors.initials: S
authors.lastname: Cheng
authors.forename: Harri
authors.initials: H
authors.lastname: Suominen
authors.forename: Päivi
authors.initials: P
authors.lastname: Saari
authors.forename: Vuokko
authors.initials: V
authors.lastname: Kovanen
authors.forename: Markku
authors.initials: M
authors.lastname: Alén
authors.forename: Taina
authors.initials: T
authors.lastname: Rantanen
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood*; D004958:Estradiol / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000453:epidemiology*; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology*; D011446:Prospective Studies; D012307:Risk Factors; D012738:Sex Hormone-Binding Globulin / Q000032:analysis*; D013739:Testosterone / Q000097:blood*; D013997:Time Factors
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D004958:Estradiol; D019314:Dehydroepiandrosterone Sulfate