Poor sleep and tendency to catastrophise linked to greater pain in osteoarthritis
Insomnia and a tendency to catastrophise amplifies the experience of pain in people with knee osteoarthritis (OA), suggests a study in the United States.
People with poor sleep patterns had increased levels of central sensitisation
Previous studies have demonstrated that a significant number of OA patients have central sensitisation (CS), a hyperexcitability in nociceptive pathways that is known to amplify and maintain clinical pain. Catastrophising, or being consumed by thoughts of pain, has also been associated with increased CS and clinical pain, but the new study is the largest and most comprehensive to investigate interactives between sleep, negative thinking and CS.
A total of 208 study participants, 72% of whom were female, were categorised into four groups: OA patients with insomnia; OA patients with normal sleep habits; healthy controls with insomnia; and healthy controls without a pain syndrome and normal sleep. They completed sleep assessments, psychological and pain evaluations, and sensory testing.
The researchers found that participants with knee OA and insomnia had the greatest degrees of CS compared with the controls. Those with poor sleep and high catastrophising scores reported increased levels of CS. In addition, CS was significantly associated with increased clinical pain.
The study does not prove cause and effect but has important implications for the treatment of chronic pain conditions such as knee OA, conclude the authors.