Mechanisms of Bone Tissue Remodeling in Young Persons with Osteoarthritis on the Background of Obesity

Abstract

The purpose of the study was to determine the content of osteoprotegerin in the blood serum of patients with osteoarthritis, based on the stage of obesity and the state of bone mineral density. Materials and methods. Under surveillance there were 75 patients with osteoarthritis, which proceeded against the background of an altered body mass index. The comparison group consisted of 50 patients with osteoarthritis and normal body weight. The age of patients in both groups was comparable, and gender balance was observed between groups. The osteoprotegerin index (pg/ml) was studied in fasting blood serum by enzyme immunoassay (ELISA) using of the FineTest EH0247 reagents, China. The prevalence of osteoporotic conditions was assessed using dual-energy x-ray absorptiometry (DEXA), HOLOGIC Explorer QDR W Series Bone Densitometer (USA). Statistical analysis was performed using the software package Statistics 10.0 and Excel 2010. Cardinal and ordinal changes were compared using the Mann-Whitney test. Correlation was calculated using Spearman's rank correlations. In all statistical analysis procedures, the level of significance p was taken equal to or less than 0.05 (p <0.05). Based on body mass index, all patients in the main group were divided into 3 subgroups. Thus, changes in body weight were recorded in 75 patients with osteoarthritis (main group). 1st stage of obesity was found in 31 patients (42%); 2nd – 22 patients (29%) and 22 patients (29%) with osteoarthritis were overweight. Results and discussion. When studying the content of osteoprotegerin in the examined patients, it was found that both in the isolated course of osteoarthritis (92.29±1.68 pg/ml) and in its combination with obesity (124.03±3.2 pg/ml), there was an increase in this indicator when compared with the results of patients in the control group (65.64±0.64, p <0.05). In order to study the state of bone mineral density in patients with osteoarthritis, a densitometric study was performed using double energy X-ray absorptiometry – DEHA (device "Expert 1188", Lunar, USA), which allowed to diagnose osteoporotic conditions. Thus, signs of osteopenia were found in 11 patients (15%) of the main and 8 people (16%) of the comparison group. Manifestations of osteoporosis were found in 18 (24%) and 5 people (10%), respectively. In patients of the main group with osteopenia, the content of osteoprotegerin in the blood serum corresponded to 108.43±0.48 pg/ml, in the comparison group – 84.86±0.87 pg/ml. With the development of osteoporosis, this value exceeded the control values, however, it was somewhat lower than with osteopenia: 99.94±1.1 and 73.57±1.66 pg/ml, respectively. Conclusion. The course of osteoarthritis is accompanied by an increase in the production of osteoprotegerin, which indicates a violation of bone tissue remodeling through increased processes of its resorption. The level of blood serum osteoprotegerin in patients with osteoarthritis has a significant increase with weight gain and its maximum value is observed in patients with 2nd stage of obesity. In patients with osteoarthritis, the formation of osteoporotic conditions (osteopenia or osteoporosis) is observed, one of the markers of which can be considered an increase in the content of osteoprotogerin glycoprotein – cytokine, which is characterized by inhibition of osteoclast production