Researchers call for individualized criteria for diagnosing obesity

With soaring obesity rates in the U.S., the American Medical Association has classified obesity as a disease. This major shift in healthcare policy brings much needed medical attention to obese patients. However, this definition of obesity focuses on a single criterion of Body Mass Index (BMI), which includes a large group of persons with high BMI who are metabolically healthy and not at high risk for type 2 diabetes, cardiovascular disease or obesity-associated cancers.

In a review article published online in Endocrinology, Gerald V. Denis, PhD, professor of pharmacology and medicine and James A. Hamilton, PhD, professor of physiology and biophysics at Boston University School of Medicine (BUSM), discusses the importance of eliminating healthy obese persons from unnecessary pharmaceutical treatments of the disease.

Previous studies have shown that the total volume of fat around the heart in obese persons is detrimental to some organ functions, but that total pericardial fat is not predicted by BMI. Thus, noninvasive imaging, such as magnetic resonance imaging (MRI), of pericardial fat could help to identify cardiovascular risks that are not clearly coupled with BMI. In addition, this could provide an opportunity to find blood biomarkers, which are the best indicators of relative metabolic status.

"These insights strongly suggest that BMI alone is insufficient to classify patients as obese and unhealthy; metabolism, body composition, fat deposition and inflammatory status must be part of a comprehensive health evaluation," said Denis.

Certain non-obese individuals may also benefit from a noninvasive imaging approach, as well. Although not apparent physically, many lean people experience significant risks for these same diseases because of chronic low-level inflammation and fat deposition in or around vital organs. Where BMI alone would exclude this group from screenings, weighing more factors that contribute to pericardial fat could save lives.

"By using a more individualized approach, some obese persons can be relieved of the additional stigma of classification in a major disease category. In addition, unnecessary medical interventions and costs can be reduced," added Hamilton.