The dissertation work is devoted to studying the influence of chronic hyperglycemia on the features of morphogenesis, chemical composition and biomechanical parameters of long tubular bones of the skeleton in the age aspect. Hyperglycemia is a consequence of acute insulin deficiency, which leads to disruption of carbohydrate, protein, fat and water-salt metabolism. This blocks the entry of glucose into insulin-dependent tissues, as a result, a severe energy deficit occurs in them. Experimental data on changes in growth parameters, the formation of bioelement composition and three-dimensional characteristics of bones under conditions of hyperglycemia give a new idea of the reaction of bone tissue taking into account the age characteristics of the organism. For a comprehensive study of the influence of chronic hyperglycemia, an experimental design was determined, which involved the use of 216 white laboratory rats of young, mature and senile age. In order to establish the effect of hyperglycemia on long tubular bones, the experimental animals were divided into two series: experimental and control, each of which was divided into three groups: young, mature, senile - depending on age, each of which was divided into six subgroups depending on the term of the experimental study. The experimental series included rats introduced into a state of hyperglycemia by means of a single intraperitoneal injection of a solution of alloxan dihydrate at a dose of 150 mg/kg of body weight in 0.9% sodium chloride solution. The animals were removed from the experiment on the 30th, 60th, 90th, 120th, 150th and 180th day. For the study, femurs and humerus bones were removed and studied using osteometric, histomorphometric, ultramicroscopic, immunohistochemical, chemical-analytical, biomechanical, computed tomography, and statistical methods. In young rats, the following changes were found against the background of hyperglycemia: the body weight deficit by the 180th day was 42.6% (p < 0.001), the glucose level varied from (19.30 ± 1.69) mmol/l (p < 0.001) at the beginning of the experiment to (13.20 ± 2.26) mmol/l (p < 0.001) at the end of the experiment, the level of glycosylated hemoglobin (HbA1c) increased from (7.0 ± 0.66)% (p < 0.001) to (9.43 ± 0.96)% (p < 0.001). According to osteometry, the linear indices of the femur and humerus of rats of the experimental and control series increased most intensively in young rats. In rats of this age group under conditions of prolonged hyperglycemia, a slowdown in the growth of osteometric indicators was observed compared to control rats. Thus, the maximum length of the femur (MCL) on the 30th day of the experiment in young rats was (18.96 ± 1.16) mm, the humerus (11.94 ± 0.77) mm (p < 0.001), which is 18% and 19% less compared to rats of the control series. The width of the mid-diaphysis of the SHD corresponded to the indicators (1.60 ± 0.37) mm and (1.07 ± 0.13) mm, which is 5% and 4.7% less compared to the control. SHE and SHE in the indicated age periods were not characterized by significant indicators. The indicators of the SHPE of the femur were (2.71 ± 0.26) mm, of the humerus – (2.07 ± 0.13) mm, the SHDE of the femur was (2.85 ± 0.22) mm, of the humerus – (2.09 ± 0.15) mm, which is marked by a slight percentage change in growth indicators compared to the indicators of rats of the control series. The indicated tendency to slow down the growth indicators of the studied bones in animals of the experimental series compared to the control was maintained until the end of the experiment. Thus, on the 180th day of the experiment, in young rats of the experimental series, the difference in the growth of osteometric indicators compared to the control increased and was: the MDC of the femur was (26.95 ± 1.06) mm (p < 0.001), the humerus – (16.80 ± 0.79) mm (p < 0.001), which is 20% and 21% less compared to the control, at the same time, the indicators of the SSD, SPE and SDE significantly increased, they increased to (1.72 ± 0.42) mm, (3.10 ± 0.04) mm and (3.26 ± 0.21) mm, respectively, the difference with the control was 7%, 8% and 7%. The body weight deficit of mature rats of the experimental series was observed at the level of 24% (p < 0.001), glucose values varied from (14.80 ± 1.30) mmol/l (p < 0.001) on the 30th day to (11.30 ± 1.10) mmol/l (p < 0.001) on the 180th day, HbA1c was 2 times higher than the norm. According to osteometry, the linear indicators of the femur of mature animals were marked by a slight percentage of increase compared to the indicators of young rats. The average indicators of the MIC of the femur and humerus on the 30th day of the experiment were slightly lower than those of the animals of the control series by 11.2% and 5.2%. The SRD compared to the control was lower by 5.3% and 4.2%, respectively. The average values of the SPE and SDE of the femur and humerus also did not differ significantly.
