Osteoprotegerin as a diagnostic indicator of chronic lower limb ischemia due to obliterating atherosclerosis combined with type 2 diabetes mellitus, and prognostic factor in its surgical treatment

Objective . To determine the concentration of osteoprotegerin in venous blood plasma in chronic lower limb ischemia due to obliterating atherosclerosis combined with type 2 diabetes mellitus, and the effect of its dynamics on the disease progression after open and roentgen-endovascular surgeries. Materials and methods . Concentration of osteoprotegerin in venous blood plasma was studied in 221 patients with chronic lower limb ischemia of atherosclerotic genesis. Two groups were formed: Group 1 (n=92) – patients with obliterating atherosclerosis without carbohydrate metabolism disorders, Group 2 (n=129) – patients with obliterating atherosclerosis and concomitant type 2 diabetes mellitus. The comparison groups included patients with type 2 diabetes mellitus without signs of obliterating atherosclerosis (Group 3, n=16), and conditionally healthy patients (Group 4, n=51). 78 patients were followed for 24 months after revascularization surgery in Group 2. The patients were divided into Group 2A (with preserved lower limb, n=60; 76.92%) and Group 2B (with amputated lower limb, n=18; 23.08%) depending on the outcome of the operation. Results. The combination of obliterating atherosclerosis of the lower limbs and type 2 diabetes mellitus is characterized by an increase in the concentration of osteoprotegerin in plasma compared to healthy individuals, patients with isolated atherosclerosis of the arteries of the lower limbs, as well as isolated type 2 diabetes mellitus (p<0.001). The threshold value of the osteoprotegerin level, the excess of which indicates a high probability of the presence of obliterating atherosclerosis in patients with type 2 diabetes mellitus is 189.37 pg/ml. The initial osteoprotegerin values in patients of Group 2A (with preserved lower limb after arterial revascularization) and Group 2B (with amputated lower limb) limb after arterial revascularization) were comparable. However, in patients of Group 2A, the concentration of osteoprotegerin gradually decreased significantly after 14 days and 3 months, while in patients of group 2B this indicator increased, preceding the amputation of the lower limb in the above-mentioned periods. Conclusion. Osteoprotegerin of venous blood plasma can be considered as one of the diagnostic factors for the presence of obliterating atherosclerosis in patients with type 2 diabetes mellitus. It is advisable to study its dynamics in the postoperative period for carrying out a set of therapeutic measures to prevent an unfavorable outcome of arterial revascularization.