[Association between red blood cell volume distribution width and osteophytes: A cross-sectional study]

To investigate the association between red blood cell volume distribution width (RDW) and osteophytes.
 Methods: This cross-sectional study was conducted in the Department of Health Examination Center of Xiangya Hospital, Central South University in Changsha, Hunan Province, China. A total of 8 334 subjects were included in this study. The severity of osteophytes was graded using the criteria of the Osteoarthritis Research Society International (OARSI). Osteophytes incident was defined as at least one side of the knee had a osteophytes grade ≥1. According to the quartiles of the RDW level, the subjects were divided into 4 groups. Multivariate logistic regression analysis was used to calculate the odds ratio (OR) and the 95% confidence interval (CI) of the knee osteophytes incidence between each RDW group and the lowest level group. Tests for linear trends were conducted based on logistic regression using a median variable of RDW level in each category.
 Results: Quartile 1 (Q1), RDW≤9.78; Q2, 9.7813.10. The multivariable adjusted ORs (95%CI) of the prevalence of osteophytes were 1.38 (1.06 to 1.79) in the second percentile interval, and 1.27 (0.97 to 1.66) and 1.50 (1.15 to 1.94) in the third and fourth percentile interval, respectively. Test for linear trends suggested that there was a positive association between the RDW level and the risk of knee osteophytes incidence (P=0.019).
 Conclusion: The risk of osteophytes incidence increases with the increasing RDW levels.