Symptomatic or radiographic knee OA increases risk of mortality
China: People with symptomatic or radiographic knee osteoarthritis (OA) are at increased risk of all‐cause mortality, according to a recent study published in the journal Arthritis Care & Research.
Osteoarthritis is a painful and debilitating disease of joints. It is the most common form of arthritis in the knee which has become one of the leading causes of disability in older adults. Presently there is no cure for knee osteoarthritis besides knee replacement.
Chao Zeng, Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China, and colleagues assessed the relation of symptomatic knee osteoarthritis (OA), knee pain, and radiographic knee OA to all‐cause mortality and identify mediators in the causal pathway.
For the purpose, the researchers studied participants in the Osteoarthritis Initiative (OAI) -- a multi-center, observational study of OA and its risk factors, with sites in Baltimore, Pittsburgh, Pawtucket, Rhode Island, and Columbus, Ohio. The participants were divided in four groups -- (1) symptomatic knee OA (i.e., both radiographic knee OA [Kellgren and Lawrence grade ≥2] and knee pain); (2) knee pain only; (3) radiographic knee OA only; and (4) neither radiographic knee OA nor knee pain.
The researchers used a multivariable Cox proportional model to analyze the link between knee OA status to all-cause mortality. In addition, they examined to what extent this link was mediated by disability, physical and mental component summary scores of quality of life and oral pain-relief medications.
Key findings of the study include:
· Among 4,796 participants, 282 died over the 96‐month follow‐up period.
· Compared with those with neither radiographic knee OA nor knee pain, multivariable‐adjusted hazard ratios (HRs) of mortality were 2.2 for symptomatic knee OA, 0.9, for knee pain only, and 2.0 for radiographic knee OA only, respectively.
· Indirect effects (HRs) of symptomatic knee OA on mortality via disability and PCS of QoL were 1.1 and 1.2 respectively.
· No apparent mediation effect was observed through either MCS of QoL or oral pain‐relief medications use.
""These findings underscore the importance of developing appropriate preventive and treatment strategies to reduce the risk of knee OA. The increased risk of all-cause mortality from symptomatic knee OA was mediated through disability and PCS of QoL, suggesting that more efforts should focus on improving function and QoL to reduce all-cause mortality among patients with symptomatic knee OA," wrote the authors.
The study, "Knee osteoarthritis, potential mediators, and risk of all‐cause mortality: data from the Osteoarthritis Initiative," is published in the journal Arthritis Care & Research.