We read with deep interest the article by Jin et al1 related to relationship between serum C reactive protein (CRP) levels measured by a high sensitivity method and osteoarthritis (OA), as well as the correlation between circulating CRP levels and OA phenotypes. We really appreciate the work which was done by the authors. However, after reading, there are some worthwhile issues that need to be explored.

First, the authors concluded “Low-grade systemic inflammation may play a greater role in symptoms rather than radiographic changes in OA” which is a cause-effect conclusion. However, 15 observational studies were …