The last step of the elimination demonstrated that present smoking (OR 0.39 [95% CI 0.18–0.84], p = 0.016) and high VAS-pain (OR 0.986 [95% CI 0.973–1.000], p = 0.044) were the independent variables to predict low IGF1 in RA patients (Supplementary Table S3). Here, IGF1 is linked to rheumatoid arthritis.