FOEDRC Research Reveals that Excess Belly Fat is Linked to Early Death in Postmenopausal Women

September

It has long been known that increased abdominal fat, is a major risk factor for developing diabetes. A new study done by Yangbo Sun, MD, PhD, and colleagues, under supervision of Wei Bao, MD, PhD, assistant professor in the Department of Epidemiology and a member of the FOEDRC, has identified  a concerning new and underrecognized complication of increased belly fat,  namely a high-risk for premature death particularly in post-menopausal women, who might not be obese or overweight. They found that women with normal weight (body mass index [BMI] 18.5-24.9 kg/m2) and central obesity (waist circumference >88 cm), are at increased risk of death from any cause, from cardiovascular disease, or from cancer.

Current public health guidelines for obesity prevention and control, focus on promoting a normal BMI, but rarely do they address central obesity, which is actually common in the general population. People with a normal weight are usually considered low risk, regardless of their waist size. However, compelling evidence has indicated the importance of waist circumference, in addition to body mass index, in assessing health risks. This new study was based on a nationwide prospective cohort of 156 624 postmenopausal women enrolled in the Women’s Health Initiative at 40 clinical centers in the United States between 1993 and 1998. These women were observed through February 2017. According to their BMI and waist circumference, these women were classified into six groups: (1) normal weight without central obesity (BMI, 18.5-24.9; WC, ≤88 cm), (2) normal weight with central obesity (BMI, 18.5-24.9; WC, >88 cm), (3) overweight without central obesity (BMI, 25.0-29.9; WC, ≤88 cm), (4) overweight with central obesity (BMI, 25.0-29.9; WC, >88 cm), (5) obese without central obesity (BMI, ≥30.0; WC, ≤88 cm), and (6) obese with central obesity (BMI, ≥30.0; WC, >88 cm). During more than 20 years of observation, women with normal weight central obesity, compared with women with normal weight and no central obesity, had a 31% higher risk of death from any cause, a 25% higher risk of death from cardiovascular disease, and a 20% higher risk of death from cancer. These risk estimates are similar to those among women who had obesity with central obesity, the highest risk subpopulation. This new study has sent a clear message that waist size is important, even among those with normal weight. Further investigations are needed to determine the best intervention strategies such as diet and lifestyle modifications to reduce the long-term risk among people with normal weight central obesity. Future guidelines will need to include waist circumference to help reclassify health risks among people with normal weight.