Pathogenetic features in patients with various phenotypic forms of obesity and osteoarthritis: focus on meta-inflammation

Background. Obesity occupies one of the leading places in the structure of non-communicable diseases and according to modern views it is a trigger factor for the occurrence of concomitant pathology, in particular, osteoarthritis. The driving force in osteoarthritis pathogenesis is not only an increase in mechanical load on the joints, but also the production of inflammatory mediators and hormones by adipose tissue, which subsequently leads to metabolic disorders in the osteoarticular system. In regard of the heterogeneity concept of obesity an important task is to study the relationship between the pathogenetic features of various obesity phenotypes and osteoarthritis development. However, despite numerous studies, there are many unresolved questions and controversial points of view on this problem. Purpose – based on the study of literary sources, mainly over the last 10 years, to analyze the pathogenetic features of obesity phenotypes and their relationship with the occurrence and progression of osteoarthritis, as well as to determine the role of inflammation in the structure of these disorders. Materials and Methods. Literature data obtained as a result of an electronic search in the MEDLINE/PubMed, Google Scholar and Web of Science databases using the following Keywords: «obesity», «metabolically healthy obesity», «metabolically unhealthy obesity», «osteoarthritis», «meta-inflammation» was studied and analyzed. Results. Obesity is characterized by a variety of phenotypes, such as: metabolically unhealthy obesity, metabolically healthy obesity, metabolic obesity with normal body weight. While metabolically healthy obesity has more favorable clinical features compared to metabolically unhealthy obesity due to the absence of metabolic disorders and lower levels of inflammatory markers, its verification is complicated with the absence of unified diagnosis criteria. The pathogenesis of osteoarthritis is closely related to obesity: the complex interaction of the metabolic syndrome components leads to the development of chronic low-level inflammation. These processes contribute to disruption of the blood and nerve supply to the joint, synovitis and cartilage destruction thus promoting osteoarthritis onset and progression. Patients with metabolically healthy obesity and metabolic obesity with normal body weight have a lower prevalence of osteoarthritis in comparison with metabolically unhealthy obesity. Conclusions. Involvement of inflammatory factors in the pathogenesis of osteoarthritis and its association with obesity and metabolic syndrome favor the relevance of studying the relationship between obesity and osteoarthritis. However, despite the results of numerous research works related to the influence of metabolic syndrome on the development of osteoarthritis, there is lack of studies on the relationship of osteoarthritis with other phenotypes of obesity, such as metabolically healthy obesity and metabolic obesity with normal body weight. The potential for transition from metabolically healthy to metabolically unhealthy obesity defines metabolically healthy obesity as a transient condition. Regarding this, further study is needed to develop unified and adequate criteria for obesity phenotypes to determine adequate management tactics and prevent the development of its complications and associated musculoskeletal system pathology.