Emerging concepts in metabolically healthy obesity

Abstract

Obesity is a major risk factor for noncommunicable diseases that is responsible for more than 70% of early deaths in the world. In the 1980's decade, some studies started to describe a "benign" obesity phenotype, named "metabolically healthy obesity" (MHO), which represents obesity without comorbidities such as hypertension, cardiovascular diseases, insulin resistance, diabetes, dyslipidemia or metabolic syndrome. However, it is still unclear if this "benign" obesity phenotype is really favorable or just a transition status to unhealthy obesity and if these subjects presented subclinical levels of cardiovascular risk that are not commonly detected. To further elucidate these issues, the investigation of pathophysiological mechanisms that can increase cardiovascular risk in MHO individuals, such as hormones and cytokines, may offer some responses. In parallel, the evaluation of subclinical cardiovascular derangement, using the systemic microcirculation as a proxy, may be an alternative to anticipate overt cardiovascular disease. Overall, further studies are needed to better understand the pathophysiology of MHO as well as to identify high-risk individuals who deserve more intensive management.

Keywords: Obesity; cardiovascular risk; cytokines; hormones; metabolically healthy obesity; microcirculation.

Figure 1

Major hormones associated with obesity pathogenesis and their association with metabolically healthy obesity. Abbreviations: HOMA-IR: homeostasis model assessment of insulin resistance index; MHO: metabolically healthy obesity; MUO: metabolically unhealthy obesity.