Table 3.

Comparison of age and vBMD by gender between non-fracture group and Grade 1 vertebral fracture (VF) group in different age bands. .

Agebands	Characteristics	Male			Female
		Non-fracture	Grade 1	p1	Non-fracture	Grade 1	p1
<50y	Number	110	17	–	241	12	–
	Age (y)	46.00 ± 2.09	46.18 ± 2.40	0.751	46.07 ± 2.30	47.00 ± 1.41	0.050
	vBMD (mg/cm3), n (%)	141.80 ± 32.6	130.23 ± 23.46	0.162	152.41 ± 32.63	128.52 ± 47.84	0.016
	Normal	88 (80.0)	12 (70.6)	0.341	201 (83.4)	7 (58.3)	0.034
	Osteopenia	18 (16.4)	5 (29.4)		37 (15.4)	4 (33.3)
	Osteoporosis	4 (3.6)	0 (0)		3 (1.2)	1 (8.4)
50-64y	Number	468	82	–	950	83	–
	Age (y)	58.34 ± 4.36	57.91 ± 4.51	0.548	57.64 ± 4.31	59.72 ± 3.85	<0.001
	vBMD (mg/cm3), n (%)	121.46 ± 31.69	104.85 ± 25.57	<0.001	109.45 ± 34.48	90.16 ± 28.66	<0.001*
	Normal	233 (49.7)	24 (29.3)	0.002	334 (35.1)	10 (12.1)	<0.001
	Osteopenia	195 (41.7)	45 (54.9)		432 (45.5)	45 (54.2)
	Osteoporosis	40 (8.6)	13 (15.8)		184 (19.4)	28 (33.7)
≥65y	Number	453	101	–	643	142	–
	Age (y)	70.73 ± 4.28	71.08 ± 4.40	0.459	69.77 ± 4.04	71.25 ± 4.27	<0.001
	vBMD (mg/cm3), n (%)	100.60 ± 32.45	89.48 ± 31.21	0.002	81.54 ± 30.07	61.62 ± 23.78	<0.001*
	Normal	132 (29.1)	17 (16.8)	0.004	66 (10.3)	4 (2.8)	<0.001
	Osteopenia	207 (45.7)	44 (43.6)		244 (37.9)	26 (18.3)
	Osteoporosis	114 (25.2)	40 (39.6)		333 (51.8)	112 (78.9)

VF, vertebral fracture; VF, fractured vertebra; vBMD, QCT volumetric bone mineral density; BMI, body mass index; WHR, waist-to-hip ratio; y, years; p, p-value.

Continuous variables were shown as mean ± standard deviance, and were tested by independent-samples t-test; ordinal categorical variables were shown as frequency(n) and percentage (%), and were tested by Kruskal-Wallis H tests.

^*, the p -value is always<0.001 before and after being adjusted by age.