Table 1.

Clinical and demographic characteristics of healthy controls and patients with early RA, chronic RA, and OA.

	Healthy Controls	Early RA	Chronic RA	OA	p, Early RA vs Chronic RA	p, Early RA vs OA	p, Chronic RA vs OA
n	45	40	74	35
Adiponectin, mg/l	4.8 ± 2.7	8.9 + 4.8^*	11.6 ± 5.7^*	14.1 ± 6.4^*	0.008	< 0.001	0.03
Age, yrs	49.5 ± 12.5	50.5 ± 13.0	56.4 ± 11.6^*	64.0 ± 9.3^*	0.01	< 0.001	< 0.001
Sex F/M	26/19	26/14	55/19	22/13	^#	^#	^#
Disease duration, yrs		0.3 ± 0.1	13.4 ± 10.6	4.1 ± 3.2	< 0.001	< 0.001	< 0.001
BMI, kg/m²	NA	24.9 ± 4.3	23.9 ± 5.3	28.9 ± 4.9	0.73	< 0.001	< 0.001
IgM RF-positive, %		65	82
DAS28		5.3 ± 1.2	NA
CRP, nmol/l		319 ± 448	220 ± 184	<75	0.90
NTJ, max 40		15.1 ± 9.4	7.2 ± 7.6		< 0.001
NSJ, max 38		11.4 ± 8.7	4.1 ± 5.3		< 0.001
HAQ (0–3)		1.0 ± 0.7	0.8 ± 0.6		0.18

↵* Statistically significant compared with healthy controls, p ≤ 0.003.
↵# No statistically significant difference between groups using chi-square test, p = 0.28. BMI: body mass index; RF: rheumatoid factor; DAS28: Disease Activity Score 28-joint count; CRP: C-reactive protein; NTJ: number of tender joints; NSJ: number of swollen joints; HAQ: Health Assessment Questionnaire; NA: not available.