compared with people without obesity and or adverse metabolic profiles, new research suggests.
The latest data on this controversial subject come from an analysis of nearly 400,000 people in the U.K. Biobank. Although the data also showed that metabolically healthy obesity poses less risk than “metabolically unhealthy” obesity, the risk of progression from healthy to unhealthy within 3-5 years was high.
“People with metabolically healthy obesity are not ‘healthy’ as they are at higher risk of atherosclerotic cardiovascular disease [ASCVD], heart failure, and respiratory diseases, compared with nonobese people with a normal metabolic profile. As such, weight management could be beneficial to all people with obesity irrespective of metabolic profile,” Ziyi Zhou and colleagues wrote in their report, published June 10, 2021, in Diabetologia.
Moreover, they advised avoiding the term metabolically healthy obesity entirely in clinical medicine “as it is misleading, and different strategies for risk stratification should be explored.”
In interviews, two experts provided somewhat different takes on the study and the overall subject.
‘Lifestyle should be explored with every single patient regardless of their weight’
Yoni Freedhoff, MD, medical director of the Bariatric Medical Institute, Ottawa, said “clinicians and patients need to be aware that obesity increases a person’s risk of various medical problems, and in turn this might lead to more frequent screening. This increased screening might be analogous to that of a person with a strong familial history of cancer who of course we would never describe as being ‘unhealthy’ as a consequence of their increased risk.”
Dr. Yoni Freedhoff
In addition to screening, “lifestyle should be explored with every single patient regardless of their weight, and if a person’s weight is not affecting their health or their quality of life, a clinician need only let the patient know that, were they to want to discuss weight management options in the future, that they’d be there for them,” said Dr. Freedhoff.
‘Metabolically healthy obesity’ has had many definitions
Matthias Schulze, DrPH, head of the molecular epidemiology at the German Institute of Human Nutrition, Potsdam, and professor at the University of Potsdam, pointed out that the way metabolically healthy obesity is defined and the outcomes assessed make a difference.
In the current study, the term is defined as having a body mass index of at least 30 kg/m2 and at least four of six metabolically healthy criteria: blood pressure, C-reactive protein, triacylglycerols, LDL cholesterol, HDL cholesterol, and hemoglobin A1c.
In May 2021, Dr. Schulze and associates reported in JAMA Network Open on a different definition that they found to identify individuals who do not have an increased risk of cardiovascular disease death and total mortality. Interestingly, they also used the U.K. Biobank as their validation cohort.
“We derived a new definition of metabolic health ... that is different from those used in [the current] article. Importantly, we included a measure of body fat distribution, waist-to-hip ratio. On the other side, we investigated only mortality outcomes and we can therefore not exclude the possibility that other outcomes may still be related. [For example], a higher diabetes risk may still be present among those we have defined as having metabolically healthy obesity.”
Dr. Schulze also said that several previous studies and meta-analyses have suggested that “previous common definitions of metabolically healthy obesity do not identify a subgroup without risk, or being at risk comparable to normal-weight metabolically healthy. Thus, this study confirms this conclusion. [But] this doesn’t rule out that there are better ways of defining subgroups.”
Clinically, he said “given that we investigated only mortality, we cannot conclude that our ‘metabolically healthy obesity’ group doesn’t require intervention.”