Dark and Light Side of Obesity: Mortality of Metabolically Healthy Obese People

Lev M Berstein


Expert Rev Endocrinol Metab. 2012;7(6):629-632. 

In This Article

Abstract and Introduction


The health effects of different obesity phenotypes remain unclear. In this observational voluminous study with prospective linkage to mortality records, participants were classified as metabolically healthy (zero or one metabolic abnormality) or unhealthy (two or more metabolic abnormalities) based on blood pressure, HDL-cholesterol, diabetes, waist circumference and low-grade inflammation signs. Obesity was defined as a BMI of 30 kg/m2 or greater. The association between metabolically healthy obesity and risk of cardiovascular disease and all-cause mortality was examined after follow-up, on average, of more than 7.0 ± 3.0 years. Participants with 'standard' (metabolically unhealthy) obesity were at elevated risk of cardiovascular disease and all-cause mortality compared with their metabolically healthy obese counterparts. No significant difference in mortality has been found between metabolically healthy obese and referent group (metabolically healthy nonobese participants). By adding new information to the data collected previously, this important paper calls for further clarifications, including an analysis of mortality in cancer and diabetic patients with various obesity types.


What is obesity? Some say that obesity is a condition of excess of body fat, others will underline that obesity is a multifaceted and heterogenous notion. In a sense, both constatations have 'right of existence' while the latter seems to be more close to the reality. Indeed, medical definitions are important when they explain how terminology is related to human health. If one admits that obesity is heterogenous, it leads him to the thought that different types of obesity are not equal to each other in regard to their health outcomes. This idea has circulated for several years and even decades, but only recently has it started to become more popular and helpful practically due to the step-by-step accumulation of facts and data.

In the paper published recently in the Journal of Clinical Endocrinology and Metabolism by two authors, Mark Hamer and Emmanuel Stamatakis, from University College of London,[1] it was concluded that obese people without metabolic disturbances (metabolically healthy obese [MHO]) are not at increased risk of cardiovascular and all-cause mortality after, on average, 7-year follow-up. Because approximately a fifth (22%) of all obese participants in this study belonged to the MHO group, such a conclusion may be considered as very important and its publication as truly deserving of an evaluation.