Table 3.

Results of univariate and multivariate logistic regression analysis for low BMD

	Univariate analysis		Multivariate analysis
	OR (95% CI)	p value	OR (95% CI)	p value
Age (years)a	1.017 (0.981–1.055)	0.353	1.066 (1.008–1.129)	0.026
Genderb	4.368 (1.791–10.652)	0.001		–e
Disease duration (years)a	1.012 (0.974–1.052)	0.539		–e
BASDAI (range 0–10)c	0.728 (0.554–0.957)	0.023	0.648 (0.455–0.923)	0.016
ESR (mm/h)c	1.012 (0.980–1.034)	0.287	1.025 (0.994–1.057)	0.112
CRP (mg/L)c	1.018 (0.994–1.042)	0.143		–e
ASDASc	0.769 (0.461–1.283)	0.315		–f
BASFI (range 0–10)c	0.959 (0.790–1.165)	0.674		–f
PINP Z-scorec	1.602 (1.043–2.461)	0.031		–e
sCTX Z-scorec	1.878 (1.262–2.794)	0.002	2.563 (1.370–4.794)	0.003
OC Z-scorec	1.766 (1.135–2.749)	0.012		–e
25OHvitD (nmol/L)c	0.998 (0.983–1.013)	0.787		–e
VFd	0.902 (0.385–2.109)	0.811		–f

See Table 1 for definitions

OR refers to the risk of low BMD (lumbar spine or hip BMD T-score ≤ −1)

^aPer year

^bIf gender is male (versus female)

^cPer 1 grade or 1 point

^dIf vertebral fracture is present (versus absent)

^eThe variable was not selected during multivariate regression analysis

^fThe variable was not tested in multivariate regression analysis because of a p value > 0.3 in univariate regression analysis, no significant correlation with lumbar spine or hip BMD T-scores, and no significant difference between men and women