Metabolically healthy and unhealthy obesity: contemporary views on the main differences. Review

Abstract

The review is devoted to discussion of the actual medical and social problem of obesity which is an independent risk factor for many chronic noninfectious diseases including cardiovascular pathology. However, since not all people with obesity demonstrate metabolic complications and obesity itself doesn’t negatively influence on the course of diseases or pathological states or threaten with a premature death from them, the review emphasize on the existing of two obesity phenotypes: metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO). Some contemporary views on the main differences between existing obesity phenotypes are expounded in the review. The definition of MHO, contemporary criteria of its revelation and its prevalence in population are elucidated in detail in the review as well as some risk factors of transformation of MHO to MUO with a consideration of the latter signs are also discussed. The data about existing risks of adverse clinical outcomes in MHO compared with MUO are presented. The contemporary views on the main differences between MHO and MUO based on such characteristics as insulin action, diet, physical activity, duration and quality of sleep, adipose tissue biology (distribution of fat accumulations, adipogenesis and lipogenesis, adipocyte size, oxygenation of adipose tissue, extracellular matrix remodeling and interstitial fibrosis, immune adipose tissue cells and inflammation, lipolytic activity of adipose tissue and adiponectin production) are interpreted in the review. MHO is emphasized to be a new conception for stratification of the patients at high risk of cardiovascular and metabolic diseases. Taking into account that different criteria of healthy metabolism are used today for evaluation of MHO, the future investigations should propose not only united definition of MHO but select some contingents of persons with MHO whose are at high risk of cardiovascular and metabolic diseases.