title: Protein intake and fracture risk in elderly people: a case-control study.
abstract: OBJECTIVE
  We investigated whether protein intake (PI) is related to osteoporotic fractures (OP) in the elderly by analyzing vegetable protein intake (VPI), animal protein intake (API), and animal/vegetable protein intake ratio (AVR) and by calcium intake (CaI).
  
  
  METHODS
  A 1:1 matched by age and sex case-control study with 167 cases was carried out at the Hospital of Jaen (Spain). Cases were patients aged ≥65 years with a low-energy fracture. Controls were people without previous fractures. Diet was assessed by a food frequency questionnaire. Multivariable analyses were fitted using analysis of covariance (for comparison of adjusted means) and conditional logistic regression (estimating adjusted odds ratios [ORs]).
  
  
  RESULTS
  The control-group showed a higher API (p = 0.046) even when CaI was <800 mg/day (p = 0.041). ORs for AVR were 0.68 (0.38-1.19) and 0.38 (0.15-0.98), respectively with a p for trend = 0.046. A PI<15% of the total energy intake showed an OR of 2.86 (1.10-7.43).
  
  
  CONCLUSIONS
  Patients with fracture history have lower API suggesting that high API reduce the occurrence of OP in elderly even if CaI is <800 mg/day. A PI<15% of total calories were associated with an increased risk of OP in elderly.
authors.affiliation: Service of Endocrinology and Nutrition, Hospital of Jaén & Division of Medicine, Health Sciences Building (B-3), University of Jaen, 23071 Jaen, Spain. mjmartin@ujaen.es
authors.forename: María José
authors.initials: MJ
authors.lastname: Martínez-Ramírez
authors.forename: Alberto D
authors.initials: AD
authors.lastname: Delgado-Martínez
authors.forename: Manuel
authors.initials: M
authors.lastname: Ruiz-Bailén
authors.forename: Carmen
authors.initials: C
authors.lastname: de la Fuente
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Martínez-González
authors.forename: Miguel
authors.initials: M
authors.lastname: Delgado-Rodríguez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002136:Calcium, Dietary / Q000008:administration & dosage; D016022:Case-Control Studies; D038441:Diet, Mediterranean / Q000208:ethnology; D018753:Diet, Protein-Restricted / Q000009:adverse effects / Q000208:ethnology; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake / Q000208:ethnology; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D058866:Osteoporotic Fractures / Q000453:epidemiology / Q000208:ethnology / Q000209:etiology* / Q000517:prevention & control; D014674:Plant Proteins, Dietary / Q000008:administration & dosage; D012306:Risk; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires
chemical_list: D002136:Calcium, Dietary; D004044:Dietary Proteins; D014674:Plant Proteins, Dietary