The associations between sleep problems and pain outcomes in people with hand osteoarthritis - Data from the Nor-hand study.

OBJECTIVE

To examine the relation of sleep problems to pain outcomes in people with hand osteoarthritis, and the extent to which central sensitization mediates these relationships.

DESIGN

In total 299 participants from the Nor-Hand cohort study rated their sleep problems (no, slight, moderate or severe problems), hand pain intensity on a Numeric Rating Scale (NRS, range: 0-10) and Australian/Canadian Osteoarthritis Hand Index (AUSCAN; range: 0-20), and overall bodily pain intensity (NRS). Central sensitization was evaluated by quantitative sensory testing. All pain questionnaires were repeated after 3.5 years. We explored the associations between sleep problems at baseline and pain outcomes at baseline and follow-up and fitted natural effect models to examine the extent to which measures of central sensitization mediated the effects of sleep problems on pain. All main analyses were adjusted for age, sex, education, comorbidities, and body mass index.

RESULTS

Slight, moderate, and severe sleep problems were reported by 33.8 ​%, 26.8 ​% and 14.3 ​%, respectively. In general, individuals with severe versus without sleep problems reported relatively more intense pain at baseline and follow up (i.e., a 1.68 (95 ​% confidence interval 0.89-2.46) higher NRS hand pain at baseline). Associations between sleep and central sensitization were weak, with no mediating effects found. For example, the indirect effect of remote pressure pain thresholds was 0.06 (-0.27, 0.39) NRS points for hand pain among individuals reporting severe sleep problems.

CONCLUSION

Sleep problems are commonly reported and related to pain intensity in people with hand osteoarthritis, while the underlying mechanisms and temporal relationship remain unclear.