Table 1.
Characteristics of early rheumatoid arthritis patients, early arthritis patients with other arthritides, and asymptomatic volunteers
| Rheumatoid arthritis (n = 195) | Arthritis patients with other arthritides (n = 159) | Asymptomatic volunteers (n = 193) | |
|---|---|---|---|
| Female, n (%) | 119 (66) | 80 (52) | 136 (70) |
| Age, mean (SD) | 55.9 (14.6) | 54.3 (17.2) | 50.7 (26.4) |
| Symptom duration (months), median (IQR) | 3.2 (1.8–6.8) | 3.0 (1.0–6.2) | – |
| Current smokers, n (%) | 38 (24) | 29 (23) | 17 (9) |
| BMI (kg/m2), median (IQR) | 26.4 (23.7–29.4) | 25.5 (22.9–27.9) | 24.1 (22.3–26.3) |
| WHO BMI classification, n (%) | |||
| Low-normal weight (BMI 18.5–24.9 kg/m2) (%) | 75 (38) | 66 (42) | 115 (60) |
| Overweight (BMI 25.0–29.9 kg/m2) (%) | 79 (41) | 70 (44) | 61 (32) |
| Obesity (BMI ≥ 30 kg/m2) (%) | 41 (21) | 23 (14) | 17 (9) |
| CRP (mg/L), median (IQR) | 9.8 (3.7–23.0) | 4.0 (3.0–15.1) | NA |
| ACPA positivity, n (%) | 107 (55) | 6 (4) | NA |
| RF positivity, n (%) | 120 (62) | 27 (17) | NA |
Three (2 %) RA patients had a low weight (BMI <18.5 kg/m2), no patients with other arthritides had a low weight, and two (1 %) asymptomatic volunteers had a low weight
Gender was missing in 11 RA patients; within early arthritis patients with other arthritides, gender, ACPA positivity and RF positivity was missing in respectively six, two, and three patients
NA not assessed, WHO World Health Organization, BMI body mass index, CRP C-reactive protein, ACPA anti-citrullinated protein antibody, RF rheumatoid factor, RA rheumatoid arthritis