To determine the associations between race (black versus nonblack) and the presence of radiographic, symptomatic, and clinical hand osteoarthritis (OA).
Using the Osteoarthritis Initiative cohort with available hand radiographs (n=4,699, black subjects n=849[18.1%], nonblack subjects n=3,850[81.9%]), propensity score-matching method was used to select black and nonblack subjects matched for known potential hand OA risk factors (age, gender, BMI, smoking status, cardiovascular disease, osteoporosis, excessive hand use, and knee OA). Posteroanterior radiographs of subjects' dominant hands were read by a musculoskeletal radiologist for this study in a blinded fashion. The modified KL grades (mKL, 0-4 scale) and the presence of erosive OA in the hand joints were recorded. Associations between race and hand OA severity criteria (mKL sum score), presence of radiographic OA (mKL≥2), erosive OA, symptomatic OA (radiographic OA with hand pain), and clinical OA (presence of Heberden's nodes) were studied using regression models. Odds ratios (ORs) and their 95% confidence interval (CI) are reported.
Black subjects had less severe hand OA (β:-1.93[95%CI:-2.53--1.34]), lower odds of radiographic (OR:0.79[95%CI:0.66-0.94]), erosive (OR:0.23[95%CI:0.11-0.47]), symptomatic (OR:0.63[95%CI:0.49-0.82]), and clinical (OR:0.49[95%CI:0.41-0.60]) hand OA.
In contrast to the well-established association between black race and knee or hip OA, odds of hand OA are lower in black versus nonblack subjects, which is not mediated by known hand OA risk factors. Future mechanistic works are warranted to determine the mediating protective factors for hand OA among the black subjects.