Table 1.

Characteristics of the premenopausal study population at blood draw, Nurses Health Study and Nurses Health Study II^a

	NHS		NHSII
	Case (n=498)	Control (n=498)	Case (n=681)	Control (n=681)
Age at blood draw, years	48.3 (3.2)	48.3 (3.2)	43.4 (4.0)	43.6 (3.9)
Age at menarche, years	12.3 (1.3)	12.5 (1.3)	12.4 (1.3)	12.5 (1.4)
BMI at age 18, kg/m2	21.1 (2.7)	21.3 (2.8)	20.8 (3.0)	21.0 (2.8)
Height, inches	64.7 (2.4)	64.6 (2.3)	65.3 (2.5)	64.8 (2.6)
BMI at blood draw, kg/m2	25.1 (4.3)	25.2 (4.9)	24.8 (4.8)	25.6 (5.4)
Weight change since age 18	10.6 (10.5)	10.5 (11.0)	10.9 (11.0)	12.2 (11.7)
Parity, children	2.6 (1.1)	2.6 (1.2)	1.7 (1.2)	2.0 (1.3)
Age at first birth, years	24.9 (2.9)	24.9 (2.8)	27.3 (4.6)	26.4 (4.5)
Physical activity, MET-hrs/wk	13.7 (22.3)	14.1 (16.8)	17.2 (19.7)	18.2 (23.1)
Alcohol consumption, g/d	4.3 (7.7)	4.5 (7.2)	3.9 (6.7)	3.2 (6.0)
History of benign breast disease, %	58	48	20	13
Family history of breast cancer, %	12	6	18	10
	Median (IQR)		Median (IQR)
Alpha-carotene, ug/dL	7.1 (4.5–11)	7.2 (4.6–12)	7.0 (4.5–12)	7.2 (4.6–11)
Beta-carotene, ug/dL	23 (15–36)	23 (15–35)	24 (16–38)	23 (15–37)
Beta-cryptoxanthin, ug/dL	10 (7.3–15)	10 (7.6–14)	10 (7.0–14)	10 (7.1–14)
Lycopene, ug/dL	43 (32–53)	43 (33–55)	42 (32–53)	43 (34–55)
Lutein-zeaxanthin, ug/dL	22 (16–28)	21 (16–27)	17 (13–22)	17 (13–22)
Total carotenoids, ug/dL	108 (86–142)	110 (87–139)	107 (83–136)	107 (83–134)
FlOP_360, FI/mL	205 (170–247)	209 (178–252)	210 (173–250)	211 (175–252)
FlOP_320, FI/mL	313 (254–426)	335 (261–451)	338 (278–441)	345 (277–455)
FlOP_400, FI/mL	65 (55–78)	66 (56–79)	64 (53–78)	64 (52–78)

^aValues are means (SD) or percentages and are standardized to the age distribution of the study population; biomarker measures are not age-adjusted.