Fig. 3

Relationships between parity, body mass index, and race with quantitative tissue composition metrics of the normal breast. Locally weighted scatter plot smoothing (Lowess) functions were used to plot the residuals estimated in multivariable linear regression models for each tissue composition metric as a function of age. Lowess plots were constructed separately for parous and nulliparous women, normal and overweight/obese women, and for Black and White women. Lowess plots were restricted to comparisons between Black and White women due to the small number of individuals in the other ethnic classes