. 2015 Jun 29;1(1):e000012. doi: 10.1136/rmdopen-2014-000012

Table 1.

Risk of inflammatory rheumatic diseases in obese participants: case–control studies and longitudinal studies

	Case–control studies	Longitudinal studies
RA	Risk of RA in obese participants: OR=1.24 (1.01 to 1.53); 813 patients with RA and 813 controls matched on age, sex and calendar year¹³ Risk of ACPA negative RA in obese participants: OR=3.45 (1.73 to 6.87); 515 recent RA with 769 controls matched on age and gender¹⁴ Risk of ACPA negative RA in obese women: OR=1.6 (1.2 to 2.2); 2748 RA with 3444 controls¹⁵	Risk of seronegative inflammatory polyarthritis in obese participants: HR 2.75 (95%CI 1.39 to 5.46) ; 25 455 participants followed for 14.2 years with 184 incident inflammatory arthritis¹⁶ Risk of seronegative RA in obese participants: HR=1.34 (1.03 to 1.74); 2 765 195 person-years of follow-up (1976–2008) in NHS and 1 934 518 person-years (1989–2009) in NHSII with 1181 incident cases of RA¹⁷
AS	NA	NA
PsA	Obesity more frequent in PsA than in RA (45% vs 39%; p=0.007, adjusted for age, sex and race); 294 PsA and 1162 RA¹⁸ Obesity more frequent in patients with PsA (37%; n=644) than in patients with psoriasis (29%, n=448), with RA (27%, n=350), or in the general population (18%)¹⁹ Risk of PsA in patients with obesity with psoriasis compared to non-obese patients with psoriasis: OR=1.22 (1.02 to 1.47); 75 395 individuals with psoriasis of which 976 developed PsA²⁰	Risk of PsA in obese participants: HR=3.12 (1.90 to 5.11); 1 231 693 person-years follow-up with 146 incident PsA²¹

ACPA, anti-citrullinated protein antibodies; AS, ankylosing spondylitis; NA, not available; PsA, psoriatic arthritis; RA, rheumatoid arthritis.