Patients with hand osteoarthritis are significantly more likely to develop disease of the hip or knee later in life, a prospective, population-based study has shown.
The new findings are consistent with reports that osteoarthritis (OA) is a generalized disease in many patients, and suggest that by “identifying subjects who have a tendency for developing OA and by modifying their risk factors, it may be possible to avoid or prevent OA-related pain and disability in the weight-bearing joints,” the investigators said.
They followed 1,235 patients who had baseline radiographs of the hand, hips, and knees that showed no prevalent OA of the hip or knee (a Kellgren/Lawrence score of 0–1) and either hand OA (a Kellgren/Lawrence score of 2–4 in two of three joint groups of either hand) or no hand OA. At a mean of 6.6 years later, they obtained hip and knee radiographs again.
Independent of other known risk factors, patients with hand OA at baseline were 3 times more likely to have future hip OA and 1.6 times more likely to have future knee OA, than patients without hand OA, reported S. Dahaghin, M.D., and colleagues at the Erasmus Medical Center at the University Medical Center Rotterdam, the Netherlands (Arthritis Rheum. 2005:52;3520–7).
When they restricted their analysis to patients without any possibility of hip or knee OA at baseline (Kellgren/Lawrence score of 0, versus 0–1), they found the risk of future knee OA was the same (odds ratio 1.6) and that the risk of future hip OA was even higher (odds ratio 6.5).
Family history of OA increased the risk of future hip OA even further in patients who had hand OA at baseline. The risk of future knee OA in these patients was further increased not by family history, but when they were overweight.
Additionally, the investigators found that high baseline levels of the OA biomarker CTX-II (type II collagen C-telopeptide degradation product) increased the risk of hip and knee OA, independent of the baseline presence of hand OA or “doubtful” hip or knee OA.
Patients in the study had a mean age of 66 years. They were a randomly selected subset of participants in the Rotterdam Study, a prospective, population-based cohort study of chronic diseases in the elderly.