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. Young women with a larger bra cup size may be at higher risk of diabetes in adulthood, says a new study led by St. Michael’s Hospital physician Joel Ray.
The study, published in the Canadian Medical Association Journal and led by Ray in collaboration with researchers at the Harvard School of Public Health, is the first to look at the link between breast size and diabetes. The prospective cohort study of 92,106 young and middle-aged women found that the larger a woman’s bra cup size at age 20, the greater her risk of developing type 2 diabetes.
“The scientific community has long cited the role of obesity as an established risk factor for type 2 diabetes,” said Ray, a researcher in the Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael’s Hospital. “While an elevated body mass index (BMI) and the distribution of fat around the abdomen are strongly linked to the onset of type 2 diabetes, little is known about the impact of breast fat. Our study’s significant findings suggest a fair correlation between the two, independent of other important factors such as BMI and waist size, and the need for further targeted research.”
According to the researchers, the age-adjusted risk of developing type 2 diabetes was two times higher for a B cup, four times higher for a C cup and five times higher for a D cup or greater. Even after adjusting for many conventional risk factors for diabetes, the risk was 1.3 times higher for B cup, 1.7 times higher for C cup, and 1.6 times higher for D cup or larger. What’s more, women with the largest bra cup developed diabetes about two years earlier (44 years) compared with those with the smallest cup size (46 years).
Source: Canadian Medical Association Journal, Canada