Table 4.

Adjusted geometric mean hormone levels by breast cancer risk factors and lifestyle-factors^a

Breast cancer risk and lifestyle factors	Participants, n	Estradiol, pg/mL	Bioavailable estradiol, %	Estrone, pg/mL	Sex hormone- binding globulin, nM/L	Androstenedione, ng/mL	DHEAS, μg/dL	Testosterone, ng/mL	Free testosterone, pg/mL
Family history of breast cancer
No	327	13.9	22.7	32.6	66.2	0.84	52.7	0.09	0.34
Yes	36	13.8	21.2	31.6	74.6	0.80	51.4	0.05	0.36
P for difference		0.90	0.18	0.57	0.12	0.66	0.83	0.08	0.40
History of benign breast disease
No	339	13.9	22.6	32.5	66.9	0.84	52.9	0.09	0.34
Yes	23	14.3	22.0	33.5	69.0	0.78	52.1	0.08	0.31
P for difference		0.69	0.68	0.67	0.75	0.61	0.92	0.72	0.38
Age at first menarche, yr
<12	101	13.7	22.9	31.6	66.7	0.83	49.5	0.08	0.33
13 or 14	166	13.9	22.2	32.4	65.2	0.83	54.8	0.09	0.34
15+	96	13.9	22.6	33.6	69.7	0.85	53.3	0.08	0.35
P for trend		0.81	0.81	0.18	0.51	0.78	0.43	0.99	0.60
P for trendb		0.70	0.47	0.30	0.24	0.68	0.29	0.83	0.39
Age at menopause, yr
<48	116	14.0	23.0	32.6	64.5	0.89	57.0	0.08	0.34
49 to 51	108	14.0	22.0	33.1	70.2	0.78	51.6	0.09	0.34
52+	139	13.6	22.5	32.1	67.0	0.80	48.5	0.09	0.33
P for trend		0.47	0.65	0.68	0.57	0.20	0.05	0.66	0.75
P for trendb		0.80	0.06	0.93	0.02	0.32	0.51	0.59	1.00
Parity
Parous	326	13.8	22.0	32.3	67.5	0.80	48.4	0.08	0.33
Nulliparous	37	13.7	23.3	32.9	67.2	0.87	58.0	0.10	0.34
P for difference		0.89	0.28	0.73	0.95	0.42	0.11	0.51	0.86
Number of birthsc
1	32	13.7	20.6	32.8	69.6	0.77	43.7	0.10	0.30
2 or 3	219	13.4	22.2	31.6	67.8	0.79	43.9	0.08	0.32
4+	75	14.7	22.3	33.2	65.8	0.86	56.0	0.08	0.35
P for trend		0.27	0.26	0.71	0.55	0.38	0.046	0.76	0.20
Age at first birthc, yr
<22	79	13.2	21.3	31.5	70.9	0.80	44.0	0.09	0.31
23 to 26.9	138	13.9	21.5	33.1	68.1	0.78	46.7	0.07	0.33
27+	109	14.7	22.3	33.1	64.3	0.84	52.2	0.10	0.32
P for trend		0.09	0.29	0.52	0.16	0.47	0.11	0.40	0.89
P for trendb		0.10	0.32	0.53	0.37	0.58	0.39	0.47	0.81
Breast-feedingc
No	27	14.3	23.2	33.5	63.4	0.82	46.9	0.09	0.33
Yes	296	13.7	21.9	32.2	67.6	0.81	47.2	0.08	0.32
P for difference		0.59	0.33	0.53	0.47	0.87	0.96	0.85	0.87
Height, cm
<150.9	107	13.8	22.3	32.2	69.4	0.84	54.7	0.09	0.34
151 to 156.9	126	14.3	22.1	33.4	67.2	0.81	51.9	0.08	0.34
157+	124	13.7	23.2	32.2	63.8	0.85	51.7	0.09	0.34
P for trend		0.83	0.31	0.99	0.16	0.91	0.54	0.71	0.86
P for trendb		0.62	0.07	0.65	0.01	0.33	0.96	0.47	0.72
BMI, kg/m2
<24.9	199	13.3	20.9	31.1	75.3	0.77	51.1	0.07	0.30
25 to 29.9	116	14.5	24.2	32.2	60.2	0.79	48.4	0.09	0.34
30+	40	15.5	26.4	38.4	51.2	1.15	65.3	0.16	0.50
P for trend		0.01	<0.01	<0.01	<0.01	0.01	0.21	0.01	<0.01
P for trendb		<0.01	<0.01	<0.01	<0.01	<0.01	0.13	0.01	<0.01
Smoking
Never smoker	310	13.2	24.3	32.0	62.9	0.80	53.5	0.09	0.35
Past smoker	37	13.6	23.7	32.4	62.3	0.77	51.4	0.06	0.38
Current smoker	14	14.9	20.0	33.2	76.3	0.94	52.8	0.12	0.29
P for difference		0.48	0.06	0.91	0.28	0.55	0.95	0.43	0.28
Alcohol drinking
Nondrinker	266	14.0	22.0	32.7	69.9	0.85	49.4	0.10	0.34
Occasional drinker	39	14.1	23.5	32.4	63.7	0.82	59.1	0.08	0.34
Regular drinker	58	13.5	22.2	32.4	67.1	0.83	49.8	0.08	0.34
P for difference		0.76	0.48	0.97	0.42	0.89	0.29	0.48	0.98
Physical activity in past 5 years
No	231	14.0	22.5	32.8	66.7	0.84	52.2	0.11	0.34
≤2 days/wk	63	13.8	22.1	32.1	67.5	0.79	50.6	0.05	0.33
≥3 days/wk	68	13.5	23.3	32.1	66.8	0.85	55.8	0.07	0.35
P for trend		0.46	0.48	0.58	0.95	0.97	0.56	0.02	0.60

DHEAS, dehyroepianrosterone sulfate; BMI, body mass index; ^aAdjusted for age (continuous), ethnic group (Japanese, Japanese Brazilians, non-Japanese Brazilians (Caucasian, mixed, Black), age at first menarche (continuous), age at menopause (continuous), number of births (0, 1, 2 or 3, 4+), age at first birth (≤22, 23 to 26, ≥27 yr, nulliparous), height (continuous), BMI (continuous), smoking (never smokers, past smokers, current smokers), alcohol drinking (nondrinkers, occasional drinkers, regular drinkers) and physical activity in the past 5 years (no, ≤2 days/wk, ≥3 days/wk); ^bContinuous variables; ^cAmong parous women only.