PNIPU: Mathematical model of microcirculation in the body of patients with diabetes

Main article: Diabetes mellitus

2023: Announcement of a mathematical model of microcirculation in the body of diabetes patients

On February 13, 2023, representatives of the Perm Polytechnic reported on the development that will help avoid dangerous complications of diabetes mellitus. 

Interstitial fluid pressure distribution normal (a) and diabetes mellitus (b)

As reported, the number of patients with diabetes mellitus is constantly growing. This disease often leads to dangerous complications. For example, disorders of the blood supply can provoke diabetic foot syndrome - pathological changes in the nervous system, arterial and microvascular beds and the bone-joint apparatus of the foot. Non-invasive experimental methods are used to diagnose them by February 2023. But similar clinical manifestations can be caused by various diseases. Biomechanics of the Perm Polytechnic University have developed a mathematical model of microcirculation in the body of patients with diabetes mellitus. It will allow you to predict the dangerous consequences of the disease and optimize diagnostics. The results of the study, scientists published in the "Russian Journal of Biomechanics" (2022). Specialists of the PSMU named after Academician E.A. Wagner also took part in the work. The study was carried out with the financial support of the Perm World-Class REC "Rational Subsoil Use." 

At the heart of type 2 diabetes is impaired insulin regulation. This leads to chronic increases in plasma glucose, free fatty acids blood and the development of life-threatening vascular diseases and complications.

With diabetes mellitus, patients may experience reperfusion syndrome - a set of complications after the restoration of blood flow in organs and tissues, where blood supply was previously reduced. This causes damage to cells, tissues and organs at various levels and leads to the development of multiple organ failure. One of the most serious complications is diabetic foot syndrome, which combines pathological changes in the peripheral nervous system, arterial and microvascular bed and bone-joint apparatus of the foot. It often leads to the development of foot ulcers and gangrene. explained Natalia Shabrykina, project manager, associate professor of the Department of Computational Mathematics, Mechanics and Biomechanics of the Perm Polytechnic Institute, candidate of physical and mathematical sciences

Diabetic foot syndrome leads to the development of ulcers in about 25% of patients, scientists say. A quarter of ulcers do not heal, putting patients at risk of amputation, with five years of mortality after which occurs in the range of 39 to 68% of cases. Statistically, 40 to 60% of non-traumatic lower limb amputations worldwide are caused by diabetic complications, and 80% follow diabetic foot ulcers. 

Isolines and current lines for interstitial fluid flow rates normal (a) and in diabetes mellitus (b)

In addition, diabetes mellitus can lead to other diseases: damage to the vascular system of the eyes, pathologies kidneys and the nervous system. Their frequency and severity are determined by microvascular complications. Scientists Perm Polytechnic University and colleagues proposed a mathematical model of microcirculation in the body, which will allow predicting these complications in advance and improving the treatment of patients. Note here that data filtration rate measurements obtained by capillaroscopy are compared. 

The model allowed to describe the biomechanical effects that occur in capillaries at the microlevel. For "re-creation" diabetic conditions scientists set a larger capillary radius, increased distance in it and increased hydraulic wall conductivity. They analyzed various microcirculation parameters: capillary radius and length, hydrostatic pressure at its arterial and venous ends, oncotic pressure, blood viscosity, hydraulic conductivity of the capillary wall, as well as hydraulic conductivity and tissue porosity. This made it possible to identify which of them affect the pressure and filtration in the vessels. 

The model was able to explain why vascular repair after injury causes an exacerbation of diabetic foot syndrome. Diabetes mellitus changes the structure of capillaries, increases the hydraulic conductivity of the capillary wall and the viscosity of the blood and leads to insufficient lymphatic drainage. These changes can be exacerbated by a drop in pressure at the arterial end of the capillary. When blood flow is restored, the expanded capillary and increased wall permeability dramatically increase the filtration rate. At the same time, due to the malfunction of the lymphatic vessels, the necessary drainage is not provided. This causes swelling and microcirculation disorders. explained the researcher

According to scientists, the development can be used to identify the causes of microcirculation disorders.