Table 2.

Demographic and physical activity characteristics by QCT measures: for women

Variable names	Category	Total (N or mean±SD)	VBMD (%)			CorTh (%)			CSA (%)			FNTB (%)
			High	Low	p value	High	Low	p value	High	Low	p value	High	Low	p value
Age group	65–74 years	1,143	63	36	<0.01	59	37	<0.01	49	41	<0.01	61	36	<0.01
	75–84 years	1,346	34	56		38	54		44	52		35	55
	(≥85 years)	193	3	9		3	9		8	7		4	8
Height at 25	m	1.6±0.5	1.7±0.5	1.6±0.5	0.11	1.6±0.5	1.6±0.5	0.99	1.7±0.5	1.6±0.5	<0.01	1.7±0.5	1.6±0.5	<0.01
Weight	kg	70±13	75±15	69±12	<0.01	75±14	69±13	<0.01	75±15	69±12	<0.01	76±14	69±12	<0.01
Current life PA		155	8	6	0.19	8	6	0.12	6	7	0.32	7	6	0.59
Early life PA		297	12	12		11	12		13	12		13	12
Lifelong PA		131	6	5		7	5		4	6		5	5
Both early and current life PA		26	1	1		1	1		1	1		1	1
Other PA combinations		97	5	4		4	4		5	4		4	4
No PA		1,760	69	72		69	72		72	71		70	72
Mid-life PA	Yes	775	35	27	<0.01	29	29	0.78	31	28	0.20	30	29	0.46
Leg muscle strength	N	255±77	275 ±74	254±76	<0.01	273 ±77	255±75	<0.01	269±76	257±76	<0.01	276±76	254±75	<0.01
Walking speed	s	7±2	7±2	7±2	<0.01	7±2	7±2	<0.01	7±2	7±2	0.08	7±2	7±2	0.01

QCT quantitative computerized tomography, VBMD vertebral BMD, CorTh femur neck cortical thickness, NCSA femur neck minimal cross-sectional area, FNTB femur neck trabecular BMD, PA physical activity