Table 2.

Baseline characteristics of controls (n = 397) by quartiles^a of OPG.

	≤4 pmol/L (N = 100)		4 < –5 pmol/L (N = 100)		5 < –6 pmol/L (N = 99)		>6 pmol/L (N = 98)		P-valueb
	N	%	N	%	N	%	N	%
Current HT	43	43.0	36	36.0	33	33.3	38	38.8	0.30
Smoking									0.93
Never	54	54.5	48	48.5	63	64.9	48	49.5
Past	42	42.4	48	48.5	29	29.9	45	46.4
Current	3	3.0	3	3.0	5	5.2	4	4.1
Alcohol consumption									0.90
Non/past drinker	24	24.0	22	22.0	31	31.3	26	26.5
<1 drink/week	33	33.0	38	38.0	30	30.3	32	32.7
1–14 drinks/week	38	38.0	36	36.0	35	35.4	35	35.7
>14 drinks/week	5	5.0	4	4.0	3	3.0	5	5.1
Episodes/week mod-stren phys activity >= 20 min									0.18
No activity	13	13.1	10	10.3	12	12.2	12	12.5
Some activity	36	36.4	33	34.0	43	43.9	37	38.5
2–<4 episodes per week	17	17.2	16	16.5	19	19.4	25	26.0
4+ episodes per week	33	33.3	38	39.2	24	24.5	22	22.9
Parent broke hip	15	15.2	9	9.0	17	17.9	14	14.7	0.81
Treated diabetes (pills or shots)	3	3.0	1	1.0	4	4.1	11	11.2	0.007
Hx of angina, MI or stroke	12	12.1	6	6.1	14	14.1	16	16.5	0.30
Self-reported health									0.003
Excellent	22	22.0	24	24.0	9	9.2	10	10.2
Very good	55	55.0	40	40.0	53	54.1	42	42.9
Good	18	18.0	28	28.0	34	34.7	38	38.8
Fair/poor	5	5.0	8	8.0	2	2.0	8	8.2
Use of corticosteroids	0	0.0	0	0.0	3	3.0	2	2.0	0.22
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	P-value
Age at screening, years	67.6	6.6	68.5	6.2	70.5	5.7	72.6	6.0	<0.001
Body-mass index (BMI), kg/m2	26.9	4.7	26.9	5.5	27.4	6.8	26.8	6.0	0.10
Total energy expenditure/week from phys act, MET-hours	14.9	14.5	16.0	14.8	14.0	13.8	14.0	15.6	0.44
Rand-36 physical function score	85.9	14.8	83.5	16.2	76.4	20.8	77.5	19.5	0.002
Total calcium intake (mg)	1239.7	730.8	1311.5	749.5	1350.2	703.0	1238.0	714.9	0.80
Total vitamin D intake (IU)	369.7	255.1	407.5	266.7	415.1	240.2	396.4	265.6	0.88
Serum parathyroid hormone (PTH; PG/mL)	21.7	7.9	21.8	7.6	22.2	8.1	21.9	8.2	0.98
10 year probability (%) of hip fracture without BMD	3.1	3.4	3.3	3.4	4.8	5.0	5.8	4.8	0.74

^aQuartiles of OPG based on controls.

^bTest of association adjusted for age.