Hand osteoarthritis becomes more prevalent with advancing age and is more common in women than men, but not in all joint areas, results from a long-term analysis demonstrated.
Over 9 years of follow-up, more men than women developed metacarpal and wrist osteoarthritis (OA), yet more women than men developed erosive and symptomatic OA, according to a report by researchers led by Dr. Ida K. Haugen of the department of rheumatology at Diakonhjemmet Hospital, Oslo, that was published in the September 2011 edition of the Annals of the Rheumatic Diseases.
In what they describe as the first study of its kind, the researchers analyzed data from 2,300 adults who participated in the Framingham OA Study to determine the prevalence and course of radiographic, erosive, and symptomatic hand OA in the general population. All study participants had bilateral hand radiographs at baseline and at 9-year follow-up (Ann. Rheum. Dis. 2011;70:1581-6).
Dr. Ida Haugen and her associates defined radiographic hand OA at the joint level as a Kellgren-Lawrence scale grade 2 or greater, erosive hand OA as a Kellgren-Lawrence grade 2 or greater plus erosion, and symptomatic hand OA as a Kellgren-Lawrence grade 2 or greater plus pain/aching/stiffness. Study participants with one or more affected joint were classified as having hand OA.
The mean age of the study participants was 59 years, 57% were women, and 96% were white. The age-standardized prevalence of hand OA was modestly higher in women compared with men (44% vs. 38%, respectively), but women had a significantly higher age-standardized prevalence of erosive OA (10% vs. 3%) and symptomatic OA (16% vs. 8%).
Over the 9 years of follow-up, the crude incidence was similar between women and men (35% vs. 34%, respectively), whereas 96% of women and 91% of men who had hand OA at baseline showed progression during follow-up.
The researchers also reported that metacarpophalangeal and wrist OA occurred more frequently and from a younger age in men, compared with women, and that development of erosive disease occurred more frequently in women, compared with men (17% vs. 10%, respectively).
"Consistent with previous studies, we found no clear evidence of higher hand OA incidence in the right hand (usually dominant)," the researchers wrote. "The symmetrical joint affection indicates that ‘wear and tear’ alone is not sufficient to explain the pattern of hand OA, and neurogenic and hormonal influences have been suggested."
They acknowledged certain limitations of the study, including the fact that participants were from a limited geographic area, which makes it "uncertain whether the results can be generalized to larger geographical areas or [nonwhite] groups," they wrote. "The offspring cohort [of the Framingham OA Study] was not randomly selected from the population. However, the participants were not chosen based on joint symptoms, and previous studies have indicated that the cohort is reasonably representative of the US population. The mean time of follow-up was 9 years, and almost all participants showed progression, making discrimination between groups difficult. It is possible but unproven that reading of radiographs in known time sequence may lead to overestimation of progression."
The Framingham Osteoarthritis Study is supported by the National Institutes of Health. Dr. Haugen disclosed that she received grants from the South-Eastern Norway Regional Health Authority and a scholarship from OARSI. Another study investigator, Dr. Martin Englund, disclosed that he received funding support from Swedish Research Council and Lund (Sweden) University, Sweden.