A new study has found that a healthy body mass index is not enough to save people with large waist circumferences from untimely death resulting from various diseases including heart disease, respiratory problems, and cancer.
The researchers pooled data from 11 different cohort studies, including more than 600,000 people from around the world. They found that men with waists 43 inches or greater in circumference had a 50 percent higher mortality risk than men with waists less than 35 inches, and this translated to about a three-year lower life expectancy after age 40.
Women with a waist circumference of 37 inches or greater had about an 80 percent higher mortality risk than women with a waist circumference of 27 inches or less, and this translated to about a five-year lower life expectancy after age 40.
Importantly, risk increased in a linear fashion such that for every 2 inches of greater circumference, mortality risk went up about 7 percent in men and about 9 percent in women.
Thus, there was not one natural 'cutpoint' for waist circumference that could be used in the clinic, as risk increased across the spectrum of circumferences.
Another key finding was that elevated mortality risk with increasing waist circumference was observed at all levels of BMI, even among people who had normal BMI levels.
Because of the large size of this pooled study, researchers were able to clearly show the independent contribution of waist circumference after accounting for BMI, James Cerhan, a Mayo Clinic epidemiologist and lead author of the study said.
Cerhan added that BMI is not a perfect measure, and it doesn't discriminate lean mass from fat mass, and it also doesn't say anything about where your weight is located.
The study is published in the March edition of Mayo Clinic Proceedings.
