Features of the Metabolism of Organic and Inorganic Matrix of Bone Tissue in Patients with Degenerative-Dystrophic Changes in the Hip Joint

Abstract

Summary. In 77 patients (37 men and 40 women) of different age groups who underwent hip joint replacement, the content of calcium, phosphorus, creatinine, alkaline phosphatase and hydroxyproline in blood serum was determined. The results of a study of biochemical markers showed the predominance of osteoporotic processes in patients of elder age groups, as is evidenced by an increase in the level of free hydroxyproline and a decrease in protein-bound hydroxyproline in blood serum, as well as by an increase in the level of hydroxyproline in daily urine excretion compared with reference indices. A decrease in calcium excretion with age both in men and women can be associated with a decrease in calcium intake and its absorption in the gastrointestinal tract, which is typical for the elderly. Calcium has the greatest importance in metabolic disorders of bone tissue. Maintaining the normal state of bones in adults is associated with continuously ongoing process called “bone remodeling”. Violation of remodeling in the direction of increasing bone resorption and reducing bone formation is considered as the main reason for the development of osteoporosis. The processes of bone formation and resorption are displayed in the blood and urine at the level of various enzymes from bone tissue, by products of bone matrix synthesis or cell destruction products. Biochemical markers of osteoporosis manifestations are specific, expressing bone synthesis and resorption processes. The violations of bone metabolism reflect most objectively not the absolute indicators of mineral metabolism and metabolites of the main bone tissue protein (collagen), but the coefficient of their ratios.