Sleep Disturbance Associated With Risk for Knee Pain, Catastrophizing in OA

Sleep disturbance among older adults with osteoarthritis (OA) is associated with pain and catastrophizing, according to study results published in Arthritis Care & Research.

Approximately half of patients with knee OA report sleep disturbances and poor sleep quality, which can contribute to the prevalence of catastrophizing.

The study was designed to evaluate the effect of sleep disturbances on knee pain and catastrophizing in patients with OA.

Researchers from Anhui Medical University in China collected data from the Osteoarthritis Initiative (OAI) for a multicenter, longitudinal, prospective, observational study. Patients with or at risk for knee OA with data on sleep disturbances and pain or catastrophizing at 48 months of the OAI study were included in the analysis.

Sleep quality in the prior week was evaluated using the Center for Epidemiologic Studies Depression Scale (CES-D); catastrophizing was evaluated using the Coping Strategies Questionnaire (CSQ); and pain was evaluated using the Western Ontario and McMaster Osteoarthritis Index (WOMAC).

Study participants had a mean age of 64.9 (SD, 9.0) years; 58.1% were women; 81.5% were White; had an average body mass index (BMI) of 28.5 (SD, 5.0); 30.3% had bilateral knee OA; and 37.1% did not have knee OA in the knees.

Among the entire cohort, 1529 reported sleep disturbances on less than 1 day in the previous week, 1634 on 1 or 2 days, 399 on 3 or 4 days, and 253 on 5 or more days in the prior week.

The prevalence ratio (PR) of knee pain was positively associated with the number of days with disturbed sleep, in which the PR was 1.36 among those with 1 or 2 days, 1.56 for those with 3 of 4 days, and 2.01 for those with 5 or more days of disturbed sleep (P <.001). A similar trend was observed for catastrophizing, with PRs increasing from 1.35 to 1.92 and 3.05 (P <.001), respectively.

During follow-up, 32% of patients without knee pain at baseline and 20% without catastrophizing developed knee pain or catastrophizing, respectively.

Any sleep disturbance significantly predicted onset of knee pain (adjusted risk ratio [aRR] range, 1.06-1.14; P <.001); however, sleep disturbance only on 5 or more days predicted catastrophizing onset (aRR, 1.71; 95% CI, 1.22-2.40; P <.001).

Among the patients with 1 or 2 days of sleep disturbance, sleep mediated 18.20% of the variance in knee pain and 6.20% of the variance in catastrophizing. The mediation percentages were 14.30% and 10.70% for those with 3 to 4 days of disturbed sleep and 13.70% and 16.40% for those with 5 or more days of disturbed sleep, respectively.

The researchers did not observe a significant indirect effect through catastrophizing for the relationship between sleep disturbances and incident knee pain, but knee pain negatively mediated the association between sleep disturbances and catastrophizing.

The study may have been limited as some outcomes were based on simple questions.

Study authors concluded, “[S]leep disturbance was associated with the presence and predicted the risk of catastrophizing and knee pain. While pain relief may benefit from the integrated management of both sleep problem and catastrophizing, sleep interventions may have a universal and independent effect in preventing incident knee pain, irrespective of catastrophizing.”

This article originally appeared on Rheumatology Advisor