BREAST SIZE AND RISK OF TYPE 2 DIABETES MELLITUS

BREAST SIZE AND RISK OF TYPE 2 DIABETES MELLITUS

Joel G. Ray MD MSc, Anshu P. Mohllajee MPH, Rob M. van Dam PhD,

 Karin B. Michels ScD PhD

Background: Elevated waist circumference and body mass  index (BMI), both traditional measures of obesity, are accepted risk factors for type 2 diabetes mellitus. Girls who are  obese experience earlier onset of puberty and possibly greater breast development. We sought to evaluate whether a woman’s breast size in late adolescence is associated with an increased risk of type 2 diabetes mellitus in adulthood.

Methods: In conjunction with the ongoing Nurses’ Health  Study II, which began to study risk factors for breast cancer among women in 1989, we conducted a prospective cohort study involving 92 106 of the participants. We assessed the risk of type 2 diabetes mellitus in relation to self-reported bra cup sizes, categorized as ≤ A, B, C and ≥ D cups, among participants at age 20. 

Results: The mean age of participants at baseline was 38.1 years. A total of 1844 new cases of type 2 diabetes mellitus arose at a mean age of 44.9 years during 886 443 personyears 

of follow-up. Relative to bra cup size ≤ A, the respective age-adjusted hazard ratios (and 95% confidence intervals [CIs]) were 2.30 (1.99–2.66) for B cup, 4.32 (3.71–5.04) for C cup and 4.99 (4.12–6.05) for ≥ D cup. Upon further adjustments  for age at menarche, parity, physical activity, smoking status, diet, multivitamin use, family history of diabetes mellitus, BMI at age 18 and current BMI, the corresponding hazard ratios (and 95% CIs) were 1.37 (1.18–1.59) for B cup, 1.80 (1.53- 2.11) for C cup and 1.64 (1.34–2.01) for ≥ D cup. The addition of waist circumference to this model minimally changed  the hazard ratios (and 95% CIs): 1.32 (1.14–1.53) for B cup, 1.71 (1.46–2.01) for C cup and 1.58 (1.29–1.94) for ≥ D cup. 

Interpretation: A large bra cup size at age 20 may be a predictor of type 2 diabetes mellitus in middle-aged women. Whether this relation is independent of traditional indicators of obesity remains to be determined. 

Canadian Medical Association Journal 2008;178(3):289-95

Laporan lengkap dari penelitian dapat dilihat di situs web CMAJ 2008;178(3):289-95, akan tetapi mengingat banyaknya faktor yang mempengaruhi ukuran payu dara, hasil penelitian ini layak untuk ditindak lanjuti dengan penelitian-penelitian yang lain terutama untuk membuktikan antara ukuran payu dara dengan risiko DM, faktor yang menghubungkannya, dan penggunaan ukuran payudara sebagai prediktor DM.