Skip to main content

Table 1 Demographic characteristics of study participants

From: Plasma metabolomic profiling in patients with rheumatoid arthritis identifies biochemical features predictive of quantitative disease activity

  Discovery cohortα Validation cohortβ
Number of RA patients/samples 64/128 12/12
Sex of RA patients (female/male) 44/20 9/3
  Visit 1 Visit 2
 DAS28-CRP
  Mean ± SD 3.1 ± 1.3 3.0 ± 1.4 2.4 ± 1.3
  Range (min–max) 1.5–7.0 1.2–6.6 1.7–5.9
 Age (years)
  Mean ± SD 62.7 ± 10.5 63.5 ± 10.6 67.8 ± 10.6
  Range (min–max) 32–85 33–86 54–84
 BMI
  Mean ± SD 30.6 ± 5.7 31.1 ± 6.2 27.0 ± 4.1
  Range (min–max) 22.4–45.3 22.8–47.8 19.0–33.3
  N/A (n) 6 6 2
 Smoking history (n)
  Current (active within 3 months) 7 5 1
  Former 31 32 3
  Never 25 27 7
  N/A 1 0 1
 CRP (mg/L)    
  Mean ± SD 8.91 ± 16.8 8.0 ± 12.7 11.5 ± 21.7
  Range (min–max) 0.29–113.0 0.7–84.0 1.0–77.1
 RFγ (n)
  Positive 36 6
  Negative 15 2
  N/A 13 4
 Anti-CCPγ (n)
  Positive 44 5
  Negative 13 1
  N/A 7 6
 Treatment
  Methotrexate use (n (%)) 48 (75.0%) 49 (76.6%) 7 (58.3%)
  Methotrexate dose (mg/week)
   Median 20.0 20.0 22.5
   IQR [Q1, Q3] [15.0, 25.0] [15.0, 25.0] [17.5,25.0]
   Prednisone use (n (%)) 29 (45.3%) 28 (43.8%) 4 (33.3%)
  Prednisone dose (mg/day)
   Median 5.0 5.0 5.0
   IQR [5.0, 7.0] [5.0, 5.0] [5.0, 5.0]
   TNFi-bDMARDsδ (n (%)) 23 (35.9%) 21 (32.8%) 3 (25.0%)
  Non-TNFi-bDMARDsε (n (%)) 6 (9.4%) 7 (10.9%) 1 (8.3%)
  Non-methotrexate csDMARDsλ (n (%)) 20 (31.2%) 27 (42.2%) 1 (8.3%)
  1. N/A Not available, RF rheumatoid factor, Anti-CCP anti-cyclic citrullinated peptide antibodies, IQR inter-quartile range, bDMARDs biologic disease-modifying anti-rheumatic drugs, csDMARDs conventional synthetic disease-modifying anti-rheumatic drugs (an expanded table with further information on demographic and clinical characteristics is provided in Additional file 2 and Additional file 3)
  2. αTraining group. Plasma samples were obtained from patients at two different time points
  3. βTest group. Plasma samples were obtained from patients at a single time point
  4. γReported only for the first visit
  5. δAdalimumab, certolizumab, etanercept, and infliximab
  6. εAbatacept, rituximab, and tocilizumab
  7. λAzathioprine, hydroxychloroquine, leflunomide, and sulfasalazine