Abstract
The proteolysis system is a link between inflammation and oxidative stress. The relationship between proteolysis and functional indicators of sarcopenia, depending on the severity of type 2 diabetes (T2D), has not been studied. Objective. To study the association of parameters of proteolysis, inflammation and oxidative stress in elderly patients with sarcopenia against the background of T2DM. Materials and methods. Тhe study included 73 patients aged 69.2±6.0 years with T2DM, divided into 3 groups: 1 — presarcopenia, 2 — sarcopenia, and 3 — comparison. The control group consisted of 9 patients aged 65.6±7.0 years. The activity of elastase- and trypsin-like proteinases, their inhibitors, and the concentrations of 8-isoprostan, TNF-α and IL1-β were determined. Statistical analysis was performed using StatTech v. 4.1.2. Results. The activity of α1-proteinase inhibitor increased with a decrease in muscle mass (p<0.05). The activity of elastase-like proteinases in sarcopenia decreased 30% compared to the comparison group and 28% compared to presarcopenia (p<0.05) with trypsin-like proteinases (p<0.05), but also with elastase-like proteinases (p<0.05). In patients taking metformin, the activity of elastase-like proteinases was 16% lower, and the activity of trypsin-like proteinases was 37% lower compared to patients who did not take the drug. The activity of elastase-like proteinases was directly proportional to the content of 8-isoprostanes in probable sarcopenia and inversely proportional in sarcopenia (p<0.05). In contrast, the relationship between IL-1β and sarcopenia was negative in presarcopenia and positive in sarcopenia (p<0.05). Trypsin-like proteinases showed a positive relationship with IL-1β in both presarcopenia and sarcopenia (p<0.05). A positive relationship with IL-1β was also found for α1-proteinase inhibitor (p<0.05). Conclusions. The imbalance of the proteolysis system in patients with DM 2 and sarcopenia is characterized by a decrease in the ratios of El/α2-MG, El/α1-PI, and Tr/α1-PI. Increased proteinase activity is accompanied by a decrease in muscle strength and endurance and correlates with an increase in 8-isoprostanes and a decrease in IL-1β in individuals with presarcopenia. In sarcopenia, a decrease in the activity of proteinases occurs against the background of a decrease in 8-isoprostanes and IL-1β and an additional decrease in the functional capacity of skeletal muscles.