Table 2.

Percent mammographic density (least square means and 95% confidence intervals) by alcohol consumption during different age intervals among premenopausal women.

Alcohol intake	No. of women	Model 1†	Model 2‡
Ages 15–17, g/day
0	942	40.9 (39.9, 41.9)	41.6 (39.1, 44.1)
>0 – <5	159	37.7 (35.5, 40.0)	38.4 (35.4, 41.4)
≥5	110	39.9 (37.1, 42.6)	40.7 (37.1, 44.4)
		Ptrend =0.43	Ptrend =0.50
Ages 18–22, g/day
0	307	41.4 (39.7, 43.2)	41.8 (38.8, 44.7)
>0 – <5	385	40.4 (38.8, 42.0)	41.1 (38.3, 43.8)
≥5 – <10	394	39.5 (38.1, 40.9)	40.1 (37.4, 42.7)
≥10	125	40.6 (38.0, 43.3)	41.0 (37.6, 44.4)
		Ptrend =0.61	Ptrend =0.59
Ages 23–30, g/day
0	280	39.9 (38.0, 41.7)	40.4 (37.4, 43.5)
>0 – <5	475	41.2 (39.9, 42.5)	41.9 (39.3, 44.5)
≥5 – <10	387	39.6 (38.1, 41.1)	40.0 (37.4, 42.6)
≥10	69	41.6 (37.9, 45.3)	41.6 (37.1, 46.0)
		Ptrend =0.94	Ptrend =0.75
Ages 31 – at mammogram, g/day
0	260	39.6 (37.7, 41.4)	40.0 (37.0, 43.0)
>0 – <5	660	40.7 (39.6, 41.9)	41.1 (38.5, 43.6)
≥5 – <10	166	40.1 (37.7, 42.5)	40.3 (37.2, 43.5)
≥10	124	40.5 (37.9, 43.1)	40.6 (37.1, 44.1)
		Ptrend =0.90	Ptrend =0.92

^†adjusted for age (continuous) and BMI (continuous) at mammogram

^‡further adjusted for parity, breast cancer in first-degree relative(s), benign breast disease, and use of oral contraceptives, all at or close to mammogram, as well as age at menarche, age at first pregnancy, and BMI at age 18