Concerning the people with RA, five studies assessed body mass index (BMI) (25.2 ± 0.7 kg/m2), in six studies RA disease duration could be determined (99 ± 36 months), four studies assessed baseline HAQ (0.9 ± 0.5), three studies assessed baseline DAS28 (4.4 ± 2.6), three studies assessed baseline CRP (2.4 ± 2.5 mg/l), one study assessed baseline ESR (38 ± 10 mm/h), four studies assessed baseline IL-6 (12.9 ± 10.4 pg/ml), and three studies assessed baseline TNF-α (18.3 ± 11.6 pg/ml). This evidence concerns the gene ESR1 and rheumatoid arthritis.