All (n=40 136) | ACPA-positive participants (n=401) | ACPA-negative participants (n=39 735) | p Value | |
---|---|---|---|---|
Age (years) | 44 (34–51) | 48 (39–54) | 44 (34–51) | <0.001 |
Gender (female) | 58% | 65% | 58% | 0.005 |
BMI (kg/m2) | 25 (23–28) | 26 (23–28) | 25 (23–28) | 0.431 |
Obesity | 15% | 14% | 15% | 0.611 |
Smoking: pack years | 0 (0–8) | 2 (0–13) | 0 (0–8) | <0.001 |
Smoking status | <0.001 | |||
Never smoker | 49% | 39% | 49% | |
Former smoker | 30% | 36% | 30% | |
Current smoker | 21% | 25% | 21% | |
Alcohol (g/day) | 3 (0–11) | 4 (0–11) | 3 (0–11) | 0.571 |
Alcohol intake, categories | 0.396 | |||
None to 5 g/day | 59% | 56% | 59% | |
5 g/day to <10 g/day | 16% | 18% | 16% | |
10 g/day or more | 25% | 25% | 25% | |
Fish intake (servings/month) | 5 (2–9) | 5 (2–9) | 5 (2–9) | 0.727 |
Sugar-sweetened soft drink intake (glasses/month) | 6 (0–22) | 5 (0–17) | 6 (0–22) | 0.053 |
Periodontitis (self-reported) | 12% | 14% | 12% | 0.263 |
Joint complaints: pain and/or stiffness in hands and/or feet | 21% | 39% | 21% | <0.001 |
Joint complaints: both pain and stiffness in hands and/or feet | 12% | 29% | 12% | <0.001 |
FDR with rheumatism | 14% | 18% | 14% | 0.014 |
Self-reported RA | 2% | 22% | 2% | <0.001 |
Defined RA | 0% | 15% | 0% | <0.001 |
In women (n=23 256) | ||||
Nulliparity | 27% | 23% | 27% | 0.182 |
Menopausal status, categories | 0.454 | |||
Premenopausal | 63% | 68% | 63% | |
Postmenopausal and hormone use | 4% | 3% | 4% | |
Postmenopausal and no hormone use | 33% | 29% | 34% | |
Regular menses | 77% | 79% | 77% | 0.707 |
Age of menarche ≤10 | 2% | 3% | 2% | 0.492 |
Data are presented as median (IQR) for continuous variables and percentages for categorical variables.
ACPA, anticitrullinated protein antibodies; BMI, body mass index; FDR, first-degree relative; RA, rheumatoid arthritis.