Knee osteoarthritis 'causes nocturnal pain that disrupts sleep'

People with severe cases of knee osteoarthritis are at an increased risk of suffering from debilitating nocturnal pain that affects their sleep habits and quality of life.

This trend has been highlighted in a new study conducted by the Hirosaki University Graduate School of Medicine in Japan, which examined data from 1,214 local volunteers in order to assess the relationship between the severity of knee osteoarthritis and sleep quality.

According to results published in the journal Arthritis Care & Research, the prevalence of nocturnal pain increased steadily as the severity of osteoarthritis rose. This, in turn, led to an increased likelihood of sleep problems, causing a significant negative impact on patients' quality of life.

Further analysis revealed that sleep problems were related to joint space narrowing and nocturnal knee pain, with cases of severe osteoarthritis also disturbing the onset and maintenance of sleep.

It has been well understood for some time that sleep disturbances frequently accompany chronic pain from osteoarthritis. Effective management of these sleep disruptions may require successful treatment of the pain itself, which is a key factor in the clinical evaluation of knee osteoarthritis.

However, this study was one of the first to correlate the prevalence of night-time knee pain with different disease severity levels and determine its influence on sleep quality, meaning the results could help to shape future therapeutic strategies.

The researchers concluded: "The prevalence of nocturnal knee pain and sleep problems increased with the severity of osteoarthritis, impacting quality of life. These results suggest the necessity of appropriate nocturnal pain control."

A spokesman for Arthritis Research UK commented: "People with osteoarthritis of the knee often report that their pain is worse during the night, and in fact night pain is often a factor that decides whether someone's osteoarthritis pain is severe enough to warrant a knee replacement surgery."