ROLE OF OSTEOPROTEHERIN IN BONE TISSUE METABOLISM IN PATIENTS WITH OSTEOARTHRITIS AND OBESITY

Abstract

SUMMARY. Osteoarthritis (OA) leads to the degeneration of the articular cartilage, and as a cause of disability it ranks first among the diseases of the musculoskeletal system. Currently, a number of researchers believe that OA can be considered in the context of metabolic syndrome, one of the components of which is obesity. According to modern concepts, muscle tissue is one of the most important human endocrine organs, since it produces a large amount of biologically active substances, hormones and special cytokines (myokines). The latter are cellular regulators of growth and degradation, and support the function of muscle mitochondria. Thus, in the course and progression of OA in patients with increased body weight and obesity, two endocrine-dependent organs "compete" – adipose and muscle tissues. In this case, we should expect not a potentiation of their impact, but a new qualitative effect. And this result of the combined course can be considered the formation of secondary osteoporosis. The aim – to optimize the diagnosis of osteopenic conditions in young people with osteoarthritis occurring against the background of overweight/obesity by determining the role of osteoprotegerin in the formation of complications. Materials and Methods. The research included the evaluation of osteoprotegerin values in 75 people with osteoarthritis (OA) proceeding against the background of obesity (main group), and 50 patients with isolated OA (comparison group). The control group consisted of 37 apparently healthy individuals. The diagnosis of OA was established based on the order of the Ministry of Health of Ukraine dated 10/12/2006 "On the provision of medical care to patients with osteoarthritis", the unified diagnostic criteria of the Association of Rheumatologists of Ukraine (2004) and the criteria of the American College of Rheumatology. The presence and severity of obesity was assessed according to the criteria of the International Diabetes Federation (IDF, 2005) based on the calculation of the body mass index (BMI) according to the Quetelet index. Results. When calculating the content of osteoprotegerin (OCG) it was found that in both examined groups this value exceeded the control values: 1.9 times in patients of the main group and 1.4 times in the comparison group. When the BMI changes in all groups of subjects, there was a significant increase in the OCG relative to control indicators. It was also found that the development and course of osteoarthritis in patients with overweight or obesity occurs against the background of increased serum osteoprotegerin. Conclusions. The course of osteoarthritis is accompanied by a significant increase of serum osteprotegerin, the level of which increases with increasing body weight. Serum osteoprotegerin indicator correlates with the radiological stage of the disease and has a maximum value at third stage of the disease. The presence of OA in obese patients is an unfavorable background for the formation of osteoporotic conditions, one of the mechanisms of which is an increase in serum osteprotegerin, a glycoprotein with an apoptotic effect at the level of osteoclasts.