title: Mechanical hyperalgesia and reduced quality of life occur in people with mild knee osteoarthritis pain.
abstract: OBJECTIVE
  This study determined whether individuals with mild knee pain due to osteoarthritis (OA) experience hyperalgesia and central sensitivity by comparing them with age-matched and sex-matched control participants and determined whether these levels are associated with pain intensity. This study also determined whether these individuals experience significantly poorer quality of life than age-matched and sex-matched controls and whether pain and function predict quality of life.
  
  
  METHODS
  Quantitative sensory tests (QSTs), including punctate pain intensity (PPI), pressure pain threshold (PPT), and heat pain threshold, tolerance, and temporal summation, were measured in 75 individuals with mild knee OA pain and 25 age-matched and sex-matched controls. Pain intensity, walking function, and quality of life were also assessed.
  
  
  RESULTS
  Significant differences were found for PPI at all sites, for PPT at the affected knee, and for quality of life. QST measures significantly correlated with pain intensity. Pain, but not function, predicted quality of life.
  
  
  CONCLUSIONS
  Individuals with mild knee pain due to OA experience mechanical (but not thermal) hyperalgesia that relates to pain intensity. They have a reduced quality of life that is predicted by pain intensity. More aggressive pain management for mild knee OA pain is indicated to improve the quality of life for individuals who are not yet candidates for joint replacement.
authors.affiliation: *College of Nursing Departments of †Physical Therapy and Rehabilitation Science ‡Biostatistics §Orthopedic Surgery, The University of Iowa, Iowa City, IA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Rakel
authors.forename: Carol
authors.initials: C
authors.lastname: Vance
authors.forename: M Bridget
authors.initials: MB
authors.lastname: Zimmerman
authors.forename: Nicole
authors.initials: N
authors.lastname: Petsas-Blodgett
authors.forename: Annunziato
authors.initials: A
authors.lastname: Amendola
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Sluka
mesh_terms: D000328:Adult; D000367:Age Factors; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications*; D010146:Pain / Q000209:etiology* / Q000523:psychology*; D017288:Pain Threshold / Q000502:physiology*; D011312:Pressure / Q000009:adverse effects; D011788:Quality of Life / Q000523:psychology*; D013223:Statistics as Topic; D064232:Visual Analog Scale