Measures of adiposity and risk of breast cancer in older postmenopausal women.
OBJECTIVE
To determine whether higher adiposity is associated with greater breast cancer risk in older postmenopausal women.


METHODS
Prospective cohort study with mean follow-up of 11.3 years.


METHODS
Four U.S. clinical centers.


METHODS
Seven thousand five hundred twenty-three women (mean age 73.5) enrolled in the Study of Osteoporotic Fractures.


METHODS
Weight, height, and waist and hip circumference were measured at baseline. Body composition was determined using bioelectrical impedance. Risk factor information was obtained by interview and questionnaire. Bone mineral density was measured using dual energy x-ray absorptiometry. The outcome was incident invasive breast cancer, confirmed using medical records.


RESULTS
After adjustment for multiple risk factors, including bone density, women in the uppermost quartiles of weight, weight gain since age 25, body mass index, waist circumference, and percentage of body fat had higher breast cancer rates than women in the first quartiles of each measure. For example, breast cancer rates were 49% higher for women in the uppermost quartile of weight (hazard ratio (HR)=1.49, 95% confidence interval (CI)=1.05-2.10), 64% higher for women in the top quartile of weight gain since age 25 (HR=1.64, 95% CI=1.15-2.34), and 58% higher for women in the top quartile of percentage of body fat (HR=1.58, 95% CI=1.11-2.23) than for women in the lowest quartile of each measure. The associations between adiposity measures and breast cancer rates were not altered when the analyses were limited to very elderly women (> or = 70).


CONCLUSIONS
Higher adiposity is an independent risk factor for breast cancer in elderly women.
Krebs
Erin E
EE
Robert Wood Johnson Clinical Scholars Program and Department of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599, USA. krebs@med.unc.edu
Taylor
Brent C
BC
Cauley
Jane A
JA
Stone
Katie L
KL
Bowman
Paula J
PJ
Ensrud
Kristine E
KE
D050154:Adiposity; D000328:Adult; D000368:Aged; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D015519:Bone Density; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D004967:Estrogens / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D017698:Postmenopause; D011446:Prospective Studies; D012307:Risk Factors; D049629:Waist-Hip Ratio
D004967:Estrogens