Table 1.

Comparison of indicators between AS and control groups.

Factor	AS	Controls	P value
n	150	168
Age (years)	29.19 ± 8.94	31.83 ± 9.97	P = NS
Gender (male/female)	127/23	128/40	P = NS
25(OH)D (nmol/L)	57.92 ± 24.42	91.24 ± 42.02	P < 0.01
ICTP (ug/L)	5.72 ± 3.88	3.69 ± 1.26	P < 0.01

Note: we compared means using t-test and proportions using chi-square test.

25-Hydroxyvitamin D (25(OH)D); pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP); ankylosing spondylitis (AS).