title: Physical activity, pain responses to heat stimuli, and conditioned pain modulation in postmenopausal women.
abstract: OBJECTIVE
  Postmenopausal women (PMW) are at high risk for disabling pain and physical inactivity. This study sought to enhance the understanding of relationships between physical activity (PA) and pain among PMW using heat pain sensitivity test and conditioned pain modulation test. We hypothesized that, compared with active women, (i) inactive women would report higher pain intensity and pain unpleasantness ratings; (ii) inactive women in disabling pain would report higher pain intensity and pain unpleasantness at high, but not low, stimulus intensities; and (iii) inactive women would have less modulation.
  
  
  METHODS
  Sixty-eight PMW rated the pain intensity and pain unpleasantness of hot stimuli presented to the thenar eminence of the hand. A subset of 31 women rated the pain intensity of a test stimulus (noxious heat) and a conditioning stimulus (cold water) as part of the conditioned pain modulation task. PA was assessed objectively with accelerometry.
  
  
  RESULTS
  Mixed-model analysis of variance (2 × 4 × 2; PA × Temperature × Pain Status) showed that inactive women in disabling pain rated pain unpleasantness higher than active women in disabling pain (F3,192 = 3.526, ∂η = 0.052, P = 0.016). Significantly lower pain unpleasantness ratings were found at the highest stimulus intensity (49°C) only for active women in disabling pain compared with inactive women in disabling pain (t11 = 2.523, P = 0.028). The other hypotheses were not supported.
  
  
  CONCLUSIONS
  PA is associated with a reduced sensitivity to the unpleasantness of painful high-intensity heat stimuli among women in disabling pain.
authors.affiliation: From the Department of Kinesiology, University of Georgia, Athens, GA.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Adrian
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: O'Connor
authors.forename: Christie L
authors.initials: CL
authors.lastname: Ward-Ritacco
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Evans
mesh_terms: D061725:Accelerometry; D000704:Analysis of Variance; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D010146:Pain / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology* / Q000523:psychology; D017698:Postmenopause / Q000502:physiology*