RESEARCH - Disease activity, sleep, psychiatric distress, and pain sensitivity in RA

[Guest guest]

The Relationship between Disease Activity, Sleep, Psychiatric Distress

and Pain Sensitivity in Rheumatoid Arthritis: A Cross-sectional Study

Posted 19 Apr 2010

C Lee; Lori B Chibnik; Bing Lu; Ajay D Wasan; R ;

Anne H Fossel; Simon M Helfgott; H ; J Clauw;

W Karlson

Arthritis Research & Therapy. 2009;11(5):R160 © 2009 BioMed Central, Ltd.

Abstract

Introduction Despite recent advances in anti-inflammatory therapy,

rheumatoid arthritis (RA) patients continue to rate pain as a

priority. The etiology of RA pain is likely multifactorial, including

both inflammatory and non-inflammatory components. In this study, we

examine the association between disease activity, sleep, psychiatric

distress and pain sensitivity in RA.

Methods Fifty-nine female RA patients completed questionnaires and

underwent pressure pain threshold testing to assess

hyperalgesia/allodynia at joint and non-joint sites. Blood samples

were taken to measure C-reactive protein (CRP). The association

between disease activity, sleep problems, psychiatric distress and

pain threshold was assessed using Pearson/Spearman correlations and

multivariable linear regression. Disease activity levels, sleep

problems and psychiatric distress were compared between RA patients

with fibromyalgia and RA patients without fibromyalgia.

Results In unadjusted analyses, CRP was not correlated with pain

threshold, but tender joint count was inversely correlated with pain

threshold at all sites (P ≤ 0.004). Sleep problems were associated

with low pain threshold at all sites (P ≤ 0.0008). Psychiatric

distress was associated with low pain threshold at the wrist and

thumbnail (P ≤ 0.006). In multivariable linear regression models, CRP

was inversely associated with wrist pain threshold (P = 0.003). Sleep

problems were inversely associated with pain threshold at all sites (P

≤ 0.01), but psychiatric distress was not. Despite differences in pain

threshold, CRP levels and sleep problems between RA patients with

fibromyalgia and those without fibromyalgia, associations between

these variables did not change when patients with fibromyalgia were

excluded.

Conclusions Multivariable models are essential in analyses of pain.

Among RA patients, inflammation is associated with heightened pain

sensitivity at joints. In contrast, poor sleep is associated with

diffuse pain sensitivity, as noted in central pain conditions such as

fibromyalgia. Future studies examining pain sensitivity at joint and

non-joint sites may identify patients with different underlying pain

mechanisms and suggest alternative approaches to treating RA pain.

****************************************

Read the full article here:

http://www.medscape.com/viewarticle/717479

Not an MD