Variability of metabolomic profiles in terms of variables related to clinical and laboratory parameters in the four principal components identified and expressed as F-values together with the corresponding p-values (in brackets).

ANOVA test, significant values (pThe results showed a correlation between PC3 scores and CRP levels and between PC1 scores and tender joint count. This last parameter only could affect the response to etanercept: in fact, the median tender joint count 28 (range) was 8 (0–21) and 12 (6–25) for responder and non-responder groups, respectively.ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; VAS: visual analogue scale; HAQ: Health Assessment Questionnaire; DAS28: disease activity score based on 28 joint counts.Variability of metabolomic profiles in terms of variables related to clinical and laboratory parameters in the four principal components identified and expressed as F-values together with the corresponding p-values (in brackets).