A Cross-Sectional Study of Association between Plasma Selenium Levels and the Prevalence of Osteoarthritis: Data from the Xiangya Osteoarthritis Study

Objectives Selenium plays an indispensable role in antioxidant and antiinflammation processes. Oxidative stress and inflammation have been hypothesized to be involved in the pathogenesis of cartilage degeneration. We sought to examine the association between plasma selenium levels and the prevalence of radiographic osteoarthritis (ROA). Design A population-based cross-sectional study. Setting and Participants Individuals aged >= 50 years were retrieved from the Xiangya Osteoarthritis (XO) Study, a community-based study conducted among the residents of the rural areas of China. Methods Plasma selenium concentration was measured by inductively coupled plasma-dynamic reaction cell-mass spectrometry. ROA was defined as Kellgren/Lawrence score >= 2 in at least one knee, hip or hand joint. The association between plasma selenium levels and ROA was evaluated by applying logistic and spline regression. Results A total of 1,032 subjects (women: 52.5%; mean age: 63.1 years; ROA prevalence: 45.4%) were included. Compared with the highest tertile, the odds ratios (ORs) for ROA were 1.24 (95% confidence interval [CI]: 0.91 to 1.68) and 1.77 (95% CI: 1.31 to 2.40) in the middle and lowest tertile of plasma selenium, respectively (P for trend<0.05). The results were not changed materially with adjustment of potential confounders. In addition, subjects who had lower plasma selenium levels exhibited a higher prevalence of ROA in a dose-response relationship manner (P=0.005). Conclusion This study suggests that subjects with lower levels of plasma selenium exhibited a higher prevalence of ROA in a dose-response relationship manner. However, additional studies are still needed to verify the potential causal relationship.