In older patients with or at risk for knee osteoarthritis (OA), 4r pain susceptibility phenotypes (PSPs) were identified, according to a study published in Arthritis & Rheumatology.
A total of 852 older adults (55% women; mean age, 67; mean body mass index, 29.5 kg/m2) with or at risk for knee OA and without persistent knee pain were enrolled from the Multicenter Osteoarthritis Study. Latent class analysis was used to determine PSPs that may contribute to the development of persistent knee pain outside of structural pathology, including widespread pain, poor sleep, psychological factors, pressure pain threshold, and temporal summation. Quantitative sensory testing (QST) was used to determine the pressure pain threshold and temporal summation. Logistic regression was used to evaluate the association between sociodemographic factors and PSPs, as well as the relationship between PSPs and the development of persistent knee pain 2 years later.
The researchers identified 4 PSPs that were primarily characterized by varying proportions (low/absent, moderate, or high) of pressure pain sensitivity and facilitated temporal summation.
Participants with a PSP characterized by a high proportion of pressure pain sensitivity and a moderate proportion of facilitated temporal summation were found to be twice as likely to develop incident persistent knee pain 2 years later (odds ratio, 1.98; 95% CI, 1.07-3.68) compared with participants with a PSP characterized by a low proportion of sensitization as assessed with pressure pain sensitivity and temporal summation.
“Understanding the mechanisms that contribute to pain susceptibility and identifying prognostic phenotypes are important steps toward the goal of phenotypic, mechanism- based management of pain,” the researchers noted.
Carlesso LC, Segal NA, Frey-Law L, et al. Pain susceptibility phenotypes in those free of knee pain with or at risk of knee osteoarthritis: the Multicenter Osteoarthritis Study. [published online October 11, 2018]. Arthritis Rheumatol. doi:10.1002/art.40752