Sleep, Pain Catastrophizing, and Central Sensitization in Knee Osteoarthritis Patients With and Without Insomnia

Campbell CM, Buenaver LF, Finan P, et al. · Arthritis Care & Research

Knee-OA patients with insomnia showed the greatest central sensitization (p = 0.01 across groups, p = 0.002 against controls, p = 0.06 against insomnia alone), and across the sample catastrophizing moderated the link between diary sleep efficiency and sensitization (interaction p = 0.007), the association holding only above a catastrophizing score of 7.4 — a level 77% of the OA-with-insomnia group reached.

Population

208 adults in four groups — 118 with knee OA and insomnia, 31 with knee OA sleeping normally, 30 with insomnia alone and 29 controls — characterized with diaries, actigraphy, home polysomnography and quantitative sensory testing

Intervention

Poor sleep efficiency (observed)

Comparator

Good sleepers

Limitations

Cross-sectional design cannot establish direction of causation; pain-processing outcomes, not cartilage structure; the groups were unequal in size and the good-sleeping OA group was older; the after-sensation component may have driven the group difference. NIH-funded; no conflicts declared.