Table 3.

Associations of dense area with age at menarche and late adolescent BMI.

	Minimally adjusted models†		Fully adjusted model§
	Estimated Difference in DA*, cm2	95% CI	Estimated Difference in DA*, cm2	95% CI
Age at menarche
<10 years	−0.35	(−1.40, 0.70)	−0.34	(−1.74, 1.05)
10–11 years	−0.64	(−1.04, −0.25)	−0.62	(−1.15, −0.10)
12–13 years	0.00	Reference	0.00	Reference
14–15 years	0.56	(0.14, 0.98)	0.42	(−0.14, 0.98)
>16 years	1.76	(0.91, 2.61)	1.59	(0.48, 2.70)
Late adolescent BMI‡
18.0 (10th percentile)	0.97	(0.89, 1.06)	0.94	(0.86, 1.03)
19.2 (25th percentile)	0.54	(0.45, 0.63)	0.52	(0.43, 0.61)
20.7 (median)	0.00	Reference	0.00	Reference
22.3 (75th percentile)	−0.57	(−0.65, −0.48)	−0.55	(−0.64, −0.46)
24.6 (90th percentile)	−1.37	(−1.45, −1.28)	−1.33	(−1.41, −1.24)

^†Models adjusted only for age at screening, BMI at screening and image batch.

^§Model with simultaneous inclusion of age at menarche and late adolescent BMI, and adjusted for age at screening, BMI at screening, menopause, MHT, parity, number of children, age at first birth, family history of breast cancer, and image batch.

^*Parameter estimates from the model for cube root of dense area were transformed to estimate the difference in dense area.

^‡Late adolescent BMI was included as a continuous covariate with a linear relationship to cube-root dense area. We present estimated differences in percent density for specific percentiles of late adolescent BMI relative to the median.