title: The correlation of hip fracture and hyponatremia in the elderly.
abstract: BACKGROUND
  Increasing age is considered one of the risk factors for hyponatremia. The concept of asymptomatic hyponatremia is not correct anymore as these patients have a greater risk for falls, bone fractures and attention impairment. The combination of old age and a fall is a common recipe for admission to a nursing home.
  
  
  METHODS
  We identified 249 patients 65 years of age or older who were admitted to hospital with the diagnosis of hip fracture secondary to fall, during a 3-year period. We compared their serum Na level on admission with that of controls: 44 ambulatory patients admitted for elective hip or knee replacement surgery during the same time frame. Odds ratios (ORs) were calculated using logistic regression.
  
  
  RESULTS
  The prevalence of hyponatremia in cases was 16.9%, versus 4.6% in controls (p=0.03). Age and hyponatremia were strongly correlated with hip fracture secondary to fall. The univariate OR for hip fracture associated with each 10-year increase in age was 5.57 (p<0.0001). After controlling for age, cases were almost 5 times as likely as controls to be hyponatremic (OR=4.80, p=0.04).
  
  
  CONCLUSIONS
  Even mild hyponatremia in the elderly should be considered a risk factor for falls. Correction of hyponatremia in the elderly may reduce morbidity and mortality, and at the same time, it has a huge impact on socioeconomic status.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Paul L Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas 79905, USA. ramin.tolouian@ttuhsc.edu
authors.forename: Ramin
authors.initials: R
authors.lastname: Tolouian
authors.forename: Tarek
authors.initials: T
authors.lastname: Alhamad
authors.forename: Maryam
authors.initials: M
authors.lastname: Farazmand
authors.forename: Zuber D
authors.initials: ZD
authors.lastname: Mulla
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D015536:Down-Regulation; D005260:Female; D006620:Hip Fractures / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D010343:Patient Admission; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012964:Sodium / Q000097:blood; D013781:Texas / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D012964:Sodium