Rheumatoid arthritis characteristics and classification of heat and cold patterns-an observational study.

Introduction: Traditional Chinese medicine (TCM) has been proven to be an effective complementary therapy in treating rheumatoid arthritis (RA). The cold pattern and the heat pattern were the two main TCM patterns for RA, which is crucial for TCM treatment. The cold pattern is characterized by fear of cold and wind, joint pain with a thin white tongue coating which can be relieved by hot herbs. In contrast, heat pattern patients suffer from severe joint pain with a yellow coating, with red swelling of the skin and high skin temperature which can be relieved by cooling herbs. Objective: We aimed to classify the heat and cold patterns in RA patients with cluster analysis and factor analysis. Moreover, we aimed to explore the association of RA characteristics between these two patterns. Methods: and Design: A cross-sectional observational research method was used, and data was collected on 300 RA patients in Hangzhou in China. Signs and symptoms associated with RA were clustered using SPSS 22.0 software. In addition, factor analysis was also used for the classification. After classification of heat and cold patterns, characteristics and treatment of the RA participants between the two patterns were explored. Results: RA patients in the study were divided into two categories using cluster analysis. Twenty-two symptoms in the first category were included in the heat pattern of RA patients. After factor analysis, nine principal components were extracted to heat pattern. The component with the highest eigenvalue (2.530) were mainly contributed by shortness of breath, palpitation, heavy limbs, chest tightness and yellow greasy tongue with high factor loading values (0.765, 0.703, 0.504, 0.429 and 0.402, respectively). Ten symptoms in the second category were included in the cold pattern of RA patients. Four principal components were extracted to cold pattern. The component with the highest eigenvalue (2.089) were mainly contributed by joint distension and pain, joint stiffness, fatigue and upset with high factor loading values (0.597, 0.590, 0.491 and 0.481, respectively). Although there were no statistical differences between the levels of rheumatoid factor and anti-cyclic peptide containing citrulline (anti-CCP), the levels of C-reactive protein, platelet count and the disease activity score using 28 joint counts were significantly higher in the heat pattern RA patients compared to the ones in cold pattern. Moreover, heat pattern RA patients were more likely to be prescribed two more disease-modifying anti-rheumatic drugs (DMARDS) combined with Methotrexate (MTX) (70.59% versus 49.72%; Conclusions: In conclusion, heat and cold patterns in RA patients could be classified well using cluster analysis and factor analysis. Most of RA patients with heat pattern were active and likely to be prescribed two more DMARDs combined with MTX.