Table 2 Associations between overweight or obesity and risk of development of rheumatoid arthritis

OR (95% CI)

OR (95% CI)

OR (95% CI)

All

BMI (OR per 5 kg/m² increase in BMI)

1.13 (1.00, 1.28)

1.17 (0.90, 1.50)

1.13 (0.98, 1.30)

BMI category vs. low-normal weight

All

Obesity

1.45 (1.07, 1.95)

1.78 (1.01, 3.12)

1.37 (0.96, 1.95)

Overweight

1.21 (0.96, 1.52)

1.29 (0.84, 1.96)

1.21 (0.92, 1.59)

Normal-underweight

Reference

Reference

Reference

≤50 years

Obesity

1.89 (1.02, 3.52)

4.63 (1.14, 18.8)

1.39 (0.68, 2.87)

Overweight

1.43 (0.89, 2.29)

2.90 (1.08, 7.76)

1.20 (0.68, 2.10)

Normal-underweight

Reference

Reference

Reference

51–59 years

Obesity

1.37 (0.76, 2.47)

1.93 (0.68, 5.50)

1.16 (0.56, 2.40)

Overweight

1.10 (0.71, 1.72)

1.02 (0.47, 2.25)

1.23 (0.72, 2.13)

Normal-underweight

Reference

Reference

Reference

60 − 65 years

Obesity

1.62 (0.91, 2.89)

1.06 (0.35, 3.23)

1.96 (0.98, 3.92)

Overweight

1.08 (0.68, 1.71)

0.60 (0.25, 1.46)

1.28 (0.73, 2.25)

Normal-underweight

Reference

Reference

Reference

≥66 years

Obesity

1.14 (0.61, 2.14)

1.15 (0.32, 4.16)

1.20 (0.58, 2.48)

Overweight

1.29 (0.81, 2.01)

1.68 (0.67, 4.21)

1.17 (0.67, 2.05)

Normal-underweight

Reference

Reference

Reference

Seropositive RA

Obesity

1.40 (1.00, 1.96)

1.33 (0.71, 2.50)

1.47 (0.99, 2.18)

Overweight

1.27 (0.99, 1.63)

1.15 (0.73, 1.84)

1.34 (0.99, 1.81)

Normal-underweight

Reference

Reference

Reference

Seronegative RA

Obesity

1.76 (0.88, 3.52)

12.3 (2.14, 71.1)

1.07 (0.47, 2.46)

Overweight

1.93 (0.51, 2.15)

3.44 (0.82, 14.5)

0.59 (0.27, 1.30)

Normal-underweight

Reference

Reference

Reference