According to the results of a study published in the Journal of Rheumatology, opioid use in patients with ankylosing spondylitis may be associated with subjective measures of disease and depression, but not objective measures of inflammation.
In a prospective cohort study of patients with ankylosing spondylitis, 706 participants underwent comprehensive clinical evaluation. Disease activity (assessed using the Bath Ankylosing Spondylitis Disease Activity Index), functional impairment (evaluated with the Bath Ankylosing Spondylitis Functional Index), radiographic severity (measured with the Bath Ankylosing Spondylitis Radiology Index and Stokes Ankylosing Spondylitis Scoring System), C-reactive protein levels, and erythrocyte sedimentation rate, in addition to other clinical and sociodemographic factors, were evaluated at baseline and every 6 months for 2 years. Researchers assessed the relationship between clinical factors and chronic and intermittent opioid use.
Baseline characteristics associated with chronic and intermittent opioid use included longer disease duration (P <.0001), smoking (P <.0001), less exercise (P =.007), lower Bath Ankylosing Spondylitis Disease Activity Index scores (P <.0001), lower Bath Ankylosing Spondylitis Functional Index scores (P <.0001), depression (P <.0001), and cardiovascular disease (P <.0001). Opioid use at baseline was associated with use of prednisone (P =.004), anxiolytics (P <.0001), muscle relaxants (P <.0001), hypnotics (P <.0001), and antidepressants (P <.0001).
In a multivariable longitudinal analysis, opioid use remained significantly associated with higher Bath Ankylosing Spondylitis Functional Index score (P =.004), higher Bath Ankylosing Spondylitis Disease Activity Index score (P =.0005), hypnotic use (P <.0001), anxiolytic use (P <.0001), older age (P =.03), and smoking (P =.02). Tumor necrosis factor inhibitor use was associated with a lower rate of opioid usage (P =.05). Opioid use was not associated with objective measures of disease state, such as elevated C-reactive protein (P =.13) or radiographic severity determined with Bath Ankylosing Spondylitis Radiology Index (P =.41).
The investigators concluded that the correlation between subjective measures of disease state and opioid use “adds support to the hypothesis that pain perception associated with [ankylosing spondylitis] may develop from sources other than spinal inflammation alone.” They noted that “alternatively, these data may also suggest the inadequacy of the biomarkers examined [erythrocyte sedimentation rate, C-reactive protein] in assessing active inflammation.”
Dau JD, Lee M, Ward MM, et al. Opioid analgesic use in patients with ankylosing spondylitis: An analysis of the prospective study of outcomes in an ankylosing spondylitis cohort [published online December 1, 2017]. J Rheumatol. doi: 10.3899/jrheum.170630