Structural and functional state of bone tissue in young people with a combined course of osteoarthritis and obesity

Abstract

In recent years, an increase in the number of patients with osteoarthritis(ОА) against the background of obesity is considered not from the point of view of mechanicalstress on the joints by an overweight patient but by the active synthesis of hormone-likesubstances by adipose tissue, which have a metabolic effect on all processes in the body. A largenumber of different chemical compounds (calcium, phosphorus, magnesium, uronic acids,tartrate-resistant bone phosphatase, and a number of others) are involved in the remodeling ofbone tissue, the balance between which determines the strength and mobility of the bone. Among
 such biochemical markers, the glycoprotein osteoprotegerin is considered. The osteoprotegerininhibits the differentiation of osteoclast precursors into osteoclasts and also regulates theirresorption in vitro and in vivo. It works by binding to RANKL on osteoblast / stromal cells,thereby blocking the RANKL-RANK ligand interaction between osteoblasts / stromal cells andosteoclast precursors.The aim of our study to establish the content of osteoprotegerin in the blood serum of youngpatients with osteoarthritis and obesity and to analyze its role in the formation of structural andfunctional changes in bone tissue. The work was performed on 75 young patients (average age -30.92 ± 0.55 years) with OA, which was established in patients with various stages of obesity; forthe comparison group, 50 individuals with an isolated course of OA of the same age (30.95 ±0.55 years) and duration of anamnesis were selected; control indicators were obtained whenexamining 37 apparently healthy individuals. The diagnosis of OA was confirmed by acomprehensive assessment of patients' complaints, anamnesis data, objective and instrumentalstudies (X-ray examination of the affected joints) while focusing on the "Protocols for themanagement of patients with osteoarthritis." The presence and severity of obesity were assessedaccording to the criteria of the International Diabetes Federation (IDF, 2005) based on thecalculation of body mass index (BMI) according to the Kettle formula. The indicator ofosteoprotegerin (pg / ml) (bone tissue glycoprotein) was investigated in fasting blood serum byenzyme-linked immunosorbent assay (ELISA) using FineTest EH0247 reagents, China. Theprevalence of osteoporotic conditions was assessed by dual-energy X-ray absorptiometry(DEXA) using the HOLOGIC Explorer QDR W Series Bone Densitometer (USA). The content ofosteoprotegerin in blood serum was studied as a biochemical marker of damage to the bone andcartilage tissue. The data obtained allowed us to say that in both groups - patients with OA (92.3± 1.68 pg / ml) and patients with a combination of OA with obesity and increased body weight
 (124.03 ± 3.2 pg / ml) - there was an increase in this glycoprotein when compared with thecontrol values ​​(65.64 ± 0.64), (p <0.001). The performed densitometric study allowed us toobtain the following results: osteopenia was identified in 15% of patients in main group and in36% - in comparison group; osteoporosis was identified in 24% of patients in main group and in10% - in comparison group.The course of osteoarthritis in young people is accompanied by theformation of osteoporotic conditions, which more often (24% versus 10%), with the addition ofobesity, lead to the development of osteoporosis. The development of osteoporotic changes inpatients with osteoarthritis and in combination with obesity is accompanied by an increase in thesynthesis of osteoprotegerin, a glycoprotein involved in the processes of bone tissue remodeling.