Table 1. Basic demographics of RA cases and healthy controls.

	Association analysis		Clinical analysis
Diagnosis	RA n = 499	HC n = 894	RA n = 220
Age (years)	57.3±12.1	41.2±12.1	58.1±11.5
Smoking (%)	13.6 (N = 308)	27.9 (N = 506)	11.8
Disease duration (years)	11.9±9.1 (N = 423)		12.1±8.9
RFa positive (%)	72.6 (N = 351)		75
ACPAb positive (%)	65.5 (N = 313)		68.6
CRPc (mg/l)	11.7±15.2 (N = 398)		13.5±16.3
DAS28d			4.6±1.4
Swollen joint count			4.4±5.1
Tender joint count			8.4±7
Morning stiffness (min)			40.9±42.6
Glucocorticoids treated (%)			59.1
Methotrexate treated (%)			61.4
Biological treatment (%)			9.1
NSAIDe treated (%)			82.7

Data are expressed as mean ± SD.

^aRF, Rheumatoid factor.

^bACPA, Anti-citrullinated peptide antibodies.

^cCRP, C-reactive protein.

^dDAS28, disease activity score 28.

^eNSAID, non-steroid anti-inflammatory drugs.