Association of body size measurements and mammographic density in Korean women: the Healthy Twin study.
BACKGROUND
Both greater body size and higher mammographic density seem to be associated with a risk of breast cancer. To understand a mechanism through which body size confers a higher risk of breast cancer, associations between mammographic measures and various measures of body size were examined.


METHODS
Study subjects were 730 Korean women selected from the Healthy Twin study. Body size measurements were completed according to standard protocol. Mammographic density was measured from digital mammograms using a computer-assisted method from which the total area and the dense area of the breast were calculated, and nondense area and percent of dense area were straightforwardly derived. Linear mixed models considering familial correlations were used for analyses.


RESULTS
Total and nondense areas were positively associated with current body mass index (BMI), BMI at 35 years, total fat percent, waist circumference, and waist-hip ratio, whereas percent dense area was inversely associated with these characteristics in both premenopausal and postmenopausal women. Height was not associated with any mammographic measure. Total and nondense areas had strong positive genetic correlations with current BMI, total fat percent, waist circumference, and waist-hip ratio, whereas percent dense area had strong inverse genetic correlations with these body size measurements.


CONCLUSIONS
Mammographic density and obesity are inversely associated with each other possibly from common genetic influences that have opposite effects on mammographic density and obesity in Korean women.


CONCLUSIONS
The association between obesity and breast cancer does not seem to be mediated through mammographic density.
Sung
Joohon
J
Department of Epidemiology, the Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, Korea.
Song
Yun-Mi
YM
Stone
Jennifer
J
Lee
Kayoung
K
Kim
Sun-Young
SY
D015992:Body Mass Index; D049628:Body Size; D001940:Breast / Q000033:anatomy & histology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007723:Korea; D016014:Linear Models; D008327:Mammography / Q000379:methods; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging*