FEATURES OF DYSLIPOPROTEINEMIA IN TYPE 2 DIABETES MELLITUS PATIENTS WITH PRIOR MYOCARDIAL INFARCTION
Authors: Altunina N.V. 
Published: November 2020

Relevance. In diabetes mellitus (DM), atherosclerotic plaques contain more fat, are more inflammatory, and show a higher risk of thrombus formation than in individuals without diabetes. One of the significant factors in the development and progression of atherosclerosis in these patients is atherogenic dyslipidemia, which includes a wide range of disorders and often precedes the onset of diabetes for several years. Therefore, it is relevant to study the features of dyslipidemia in patients with diabetes after myocardial infarction (MI).

Objective: to study changes in blood lipid spectrum parameters, including Apolipoproteins (Apo A-1, Apo B) and lipoprotein (a), in postinfarction patients with type 2 DM.

Materials and methods. 119 patients (77 men and 42 women; mean age 61.09 ± 0.92 years) were examined, of which 42 were patients with coronary heart disease (CHD) who suffered from MI and type 2 diabetes (main group), 39 patients with a history of MI without concomitant diabetes (comparison group I) and 38 patients with type 2 diabetes without MI (comparison group II). The control group consisted of 30 healthy individuals, comparable in age and sex. Total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDLC) were determined in venous serum by enzymatic colorimetric method. According to the formulas, the level of cholesterol in very-low-density lipoproteins (VLDLC) was calculated; cholesterol in low-density lipoprotein (LDLC), coefficient of atherogenicity (CA). The level of lipoprotein (a) – LP (a), Apo A-1, and Apo B were determined by immunoturbidimetry. Blood sampling in patients was performed on an empty stomach.

Results. In the main group, significantly higher rates of TC, TG, LDLC, VLDLC, AF, Apo B, and the ratio of Apo B/Apo A-1, compared with non-diabetic postinfarction patients. At the same time, there was a significantly lower concentration of HDLC, Apo A-1, and LP (a) – in patients with a history of diabetes mellitus. When comparing the indicators of patients in the main group with patients with isolated type 2 diabetes, there were significantly higher levels of LDL cholesterol and CA, as well as significantly lower concentrations of HDL cholesterol and apo A-1 in patients of the main group. The analysis of lipid metabolism in the comparison groups revealed a difference in the level of TG, LDL cholesterol, and Apo B, which have higher levels in patients with isolated type 2 diabetes, and the level of LP (a) – significantly higher in postinfarction patients, in contrast to diabetics. The results indicate deeper disorders of lipid metabolism in post-infarction patients with diabetes than in non-diabetic post-infarction patients, which may be due to insulin resistance, hyperinsulinemia, and hyperglycemia.

Conclusions. Dyslipoproteinemia in postinfarction patients with type 2 diabetes is characterized by a decrease in the content of antiatherogenic HDL cholesterol and its protein Apo A-1, moderate hypertriglyceridemia, increased levels of LDL cholesterol, VLDL cholesterol, and Apo B, which causes higher values of cholesterol and increases AF. Elevations in lipid profile parameters such as TG, LDL cholesterol, and Apo B are more associated with diabetes, while higher concentrations of LP (a) are characteristic of postinfarction non-diabetic patients.