Table 5

Baseline characteristics of all participants without RA; ACPA-positive (≥6.2 U/mL) versus ACPA-negative

All (n=39 298)ACPA-positive participants (n=311)ACPA-negative participants (n=38 987)p Value
Age (years)44 (34–51)46 (35–52)44 (34–51)0.017
Gender (female)58%62%58%0.103
BMI (kg/m2)25 (23–28)25 (23–28)25 (23–28)0.834
Obesity15%13%15%0.444
Smoking: pack years0 (0–8)1 (0–11)0 (0–8)<0.001
Smoking status0.006
 Never smoker49%40%49%
 Former smoker30%35%30%
 Current smoker21%25%21%
Alcohol (g/day)3 (0–11)3 (0–9)3 (0–11)0.861
Alcohol intake, categories0.499
 None to 5 g/day59%57%59%
 5 g/day to <10 g/day16%18%16%
 10 g/day or more25%24%25%
Fish intake (servings/month)5 (2–9)5 (2–9)5 (2–9)0.754
Sugar-sweetened soft drink intake (glasses/month)6 (0–22)6 (0–20)6 (0–22)0.270
Periodontitis (self-reported)12%14%12%0.284
Joint complaints: pain and/or stiffness in hands and/or feet20%26%20%0.018
Joint complaints: both pain and stiffness in hands and/or feet11%15%11%0.026
FDR with rheumatism14%15%14%0.476
In women (n=22 727)
Nulliparity27%28%27%0.926
Menopausal status, categories0.145
 Premenopausal63%73%63%
 Postmenopausal and hormone use4%4%4%
 Postmenopausal and no hormone use33%23%34%
Regular menses78%78%78%0.984
Age of menarche ≤102%3%2%0.302
  • 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.