Abdominal obesity/body fat distribution: Abdominal obesity is a serious health risk factor for mortality

The importance of abdominal obesity beyond overall general adiposity as a risk factor for total mortality has been confirmed in the largest prospective study ever conducted on the topic. In a recent paper published in the New England Journal of Medicine (Volume 359, number 20, 2105-2120), investigators of the EPIC study examined the association of general adiposity (body mass index, BMI) and abdominal obesity (waist circumference or waist-to-hip ratio) to the risk of death in this cohort study of 359,387 participants (65.4% women) from nine European countries followed for 9.7±2.0 years.

There was a nonlinear association between BMI and the risk of death. The lowest risk of death was observed at BMI values of 25.3 kg/m2 in men and 24.3 kg/m2 in women, while the highest risks were in the lower and upper BMI categories. A similar pattern was observed for waist circumference and waist-to-hip ratio when results were not adjusted for BMI. However, after adjusting for BMI, waist girth and waist-to-hip ratio were positively associated with risk of death. The relationships of waist circumference or waist-to-hip ratio to the risk of death seemed to be stronger in subjects with lower BMI values. For instance, participants who were simultaneously in the lowest tertile of BMI and in the highest quintile of waist circumference had the highest risk of death. However, among obese individuals, elevated waist circumference had only a modest influence on mortality.

In summary, this remarkable paper from the EPIC study provides robust evidence that health professionals should systematically measure waist circumference in order to better assess the risk of mortality related to abdominal obesity. A measuring tape should therefore accompany the stethoscope in the white coat of physicians.