The following is a summary of “Associations of pain sensitivity and conditioned pain modulation with physical activity: findings from the Multicenter Osteoarthritis Study (MOST),” published in the May 2024 issue of Rheumatology by Lee et al.

Individuals with chronic knee osteoarthritis (OA) often exhibit low levels of physical activity, which is linked to common alterations in facilitatory and inhibitory nociceptive signaling. Using data from the Multicenter Osteoarthritis Study, the study aimed to explore how these nociceptive signaling changes correlate with objective measures of physical activity.

Methodologically, researchers assessed pain sensitivity through pressure pain threshold at the knee for peripheral sensitivity and mechanical temporal summation at the wrist for central sensitivity. Investigators also evaluated the presence of descending pain inhibition using conditioned pain modulation (CPM). Physical activity was quantitatively measured over 7 days using a lower back-worn activity monitor, focusing on metrics such as steps per day, activity intensity, and sedentary time. Linear regression analyses were employed to determine the associations between pain sensitivity, CPM, and these physical activity measures.

The analysis included data from 1,873 participants (55.9% female, mean age = 62.8 ± 10.0 years). The study group found greater peripheral and central pain sensitivity was significantly associated with lower daily step counts. Interestingly, CPM did not show a significant relationship with any physical activity metrics, nor did any exposures correlate significantly with sedentary time.

In conclusion, the findings highlight that heightened pain sensitivity is linked to reduced daily step counts in individuals with knee OA both peripherally and centrally. Future research should focus on interventions targeting pain sensitivity modulation to enhance physical activity levels among older adults affected by knee OA. These efforts may contribute to improved management strategies to promote mobility and overall health in this population.

Source: sciencedirect.com/science/article/abs/pii/S1063458424011956