To study the prevalence of type II diabetes mellitus as a high–risk factor in patients with coronary heart disease undergoing coronary artery bypass grafting on a beating heart

Objective . To study the prevalence of type II diabetes mellitus in patients with coronary heart disease who are to undergo coronary artery bypass grafting on a beating heart. Materials and methods. The study included 991 patients: 786 (79.3%) men and 205 (20.7%) women aged 39 to 84 years, with a mean age of (64.3 ± 1.4) years. Men were aged 39 to 84 years, with a mean age of (62.7 ± 1.7) years, and women were aged 44 to 82 years, with a mean age of (66.0 ± 2.4) years. All study participants underwent coronary artery bypass grafting in the period from 2018 to 2021. The frequency of type II diabetes mellitus in different clinical groups of the study was analysed, taking into account its clinical course, compensation status and patient gender. Statistically, the data were processed using the (cid:548)(cid:240) criterion with the Yates correction. Results. It was found that the incidence of type II diabetes mellitus is 2.5 times higher in patients with coronary heart disease than in the general population. The prevalence of type II diabetes mellitus is statistically significantly higher in women with two and three or more coronary arteries. Conclusions. The annual reports of the International Diabetes Federation and numerous scientific studies on type II diabetes mellitus prove that this pathology is extremely common, creates a risk of coronary heart disease, complicates its course, treatment and rehabilitation of patients. A statistical analysis of the prevalence of type II diabetes mellitus showed that in the cohort of patients to undergo coronary artery bypass grafting on a beating heart, it is statistically significantly more common in women with two and three or more coronary arteries affected.

Type II diabetes mellitus (T2DM) and arterial hypertension (AH) often accompany the clinical course of coronary heart disease (CHD), pathogenetically complicate it, worsening the prognosis of surgical treatment and rehabilitation, and significantly reduce the quality of life of patients [1].These diseases are extremely common in all populations of the world's population.Having a hereditary component, they are often inherited by a polygenic type, i.e. by a linked group.These diseases are also characterised by high rates of mortality and disability among the working-age population [1][2][3][4].
Every year on 14 November, the World Diabetes Day is celebrated.The media widely cover the issue of the extreme prevalence of this pathology.According to the International Diabetes Federation, about 537 million adults worldwide have type II diabetes, i.e. every 10th inhabitant of our planet.Experts predict that by 2030 the number of such patients will increase to 643 or even 700 million [5].In Ukraine today, about 1 million 300 thousand people have this disease, i.e. every 30th citizen of Ukraine has T2DM, and its prevalence is increasing every year.
It has been established that T2DM is one of the main risk factors for the development of circulatory system diseases (CVD) [6].And additional risk factors for CVD include impaired glucose tolerance, which subsequently leads to the development of T2DM [7].
Many patients with coronary heart disease have type II diabetes.For such patients, it is important to control blood pressure (BP), body weight, cholesterol, heart rate, and, during the COVID-19 pandemic, blood oxygen saturation, as they are at extremely high risk [5].
Thus, the study of the prevalence of T2DM in a cohort of patients with coronary artery disease who are to undergo coronary artery bypass grafting (CABG) on a beating heart is an urgent medical and social problem of our time.
The aim of the study was to investigate the prevalence of T2DM in patients with coronary artery disease who are to undergo CABG on a beating heart.

Materials and methods of the study
All study participants (n=991), with a mean age of (64.3 ± 1.4) years and a range of ages from 39 to 84 years, were treated in the Department of Coronary Artery Disease Surgery at the Amosov National Institute of Cardiovascular Surgery in 2018-2021.The study included 786 (79.3%) men, whose mean age was (62.7 ± 1.7) years, and the age range was from 39 to 84 years, and 205 (20.7%) women, whose mean age was (66.0 ± 2.4) years, and the age range was from 44 to 82 years.
Inclusion criteria: confirmed diagnosis of coronary heart disease, age over 18 years.Criteria for exclusion of patients UJCS.2023 July/August; 90(4) The Ukrainian Journal of Clinical Surgery from the study: left ventricular (LV) aneurysm, acquired and congenital heart disease, and postinfarction ventricular septal deformity.The material for the study and analysis was an extract from the medical record of an outpatient (inpatient) patient (form No. 027/o), and a medical record of an inpatient (form No. 003/o).To confirm the diagnosis of coronary artery disease, peculiarities of localisation, severity, extent of coronary artery disease (CAD), number of affected CAD, and assessment of the functional state of the LV myocardium, all study participants underwent selective coronary angiography by the Judkins method.In addition, all study participants underwent clinical and diagnostic examination in accordance with the protocol for inpatient care.For therapeutic purposes and in accordance with the study inclusion criteria, all participants underwent CABG on a beating heart (of pump) with mandatory determination of the degree of cardiovascular risk before surgery using the EuroSCORE II scale (European System for Cardiac Operative Risk Evaluation).Statistically significant differences were determined at a significance level of p<0.05 by the test with the Yates correction.
The materials used in this study do not violate the principles of bioethics if published (extract from Minutes No. 4 of the meeting of the Institute's Bioethics Committee of 20.11.2020).All patients who participated in the study signed an informed voluntary consent.
The difference between the average age of the women who participated in the study -(66.0 ± 2.4) years, and the average age of men -(62.7 ± 1.7) years was not statistically significant (p 0.05).
The presence of T2DM was established based on medical and life history data, as well as biochemical blood tests.
In the study cohort (n=991), T2DM was detected in 256 patients with CHD, which was 25.8% and higher than the prevalence of T2DM reported by the International Diabetes Federation, according to which one in 10 people has this disease.This can be explained by the specificity of our sample -the comorbidity of synergistic pathologies such as CAD, hypertension, T2DM, overweight, etc.
To ensure the adequacy of the analysis of the presence of diabetes mellitus, its frequency was studied in clinical groups of patients with one, two, and three or more CAD lesions, taking into account the clinical grade, the state of compensation for diabetes mellitus, which is important for the possibility of performing CABG on a working heart, and the patient's sex (Table 1).
The frequency of T2DM in women was as follows: in the clinical group with one CAD lesion -50.0%; two CAD lesions -66.7%, three or more CAD lesions -42.4%.Thus, it was found that the highest incidence of T2DM was in women in the clinical group with two CAD lesions (66.7%), and the lowest -in women in the clinical group with three or more CAD lesions (42.4%).The difference between these indicators is statistically significant: p=0.03, 2 = 4.59 (Table 2).
We also studied the incidence of T2DM in men in different clinical groups (Table 3).
It was established that the highest incidence of T2DM was in men with lesions of three or more CAD (21.5%), and the lowest incidence of T2DM was in men with lesions of one CAD (11.1%), but the difference between these indicators was statistically insignificant (p 0.05).
Subsequently, we performed a comparative analysis of the obtained rates of T2DM in men and women in each clinical group (Table 4).
Thus, we found that the incidence of DM II in men was 20.6% (162 out of 786), and in women -45.9% (94 out of 205).Thus, the incidence of T2DM is statistically significantly higher in patients with coronary artery disease who are to undergo CABG on an exercising heart (p=0.0001, 2 = 52.7).It was also found that T2DM in clinical groups with two CAD lesions and with three or more CAD lesions was statistically significantly more common in women than in men (p=0.0001, 2 = 24.87 and p=0.0001, 2 = 30.21,respectively).Next, the clinical degree and state of compensation of T2DM in the study participants were assessed.It should be noted that no decompensated state of T2DM was detected in the patients who participated in the study, because the presence of T2DM decompensation would make it impossible to perform CABG on a working heart.Regarding the severity of the clinical course of T2DM, it was found that out of 256 patients with T2DM, 170 (66.4%) had a mild clinical course.The remaining 86 (33.7%) patients had moderate severity of T2DM (see Table 1).

The Ukrainian Journal of Clinical Surgery
When analysing the severity of the clinical course of T2DM in men and women, no statistically significant differences were found (p 0.05).At the same time, it was found that the incidence of mild T2DM in women was 6.0% higher than in men, and the incidence of moderate T2DM was higher in men than in women: 35.8 and 29.8%, respectively (see Figure ).

Discussion
It was found that the prevalence of T2DM in the participants of this study was 25.8%, which means that every 4th person had this disease.The obtained frequency of T2DM exceeds the corresponding figure given in the report of the International Diabetes Federation by 2.5 times, i.e., according to the report, every 10th person has T2DM [7,8].This discrepancy can be explained by the specificity of our sample of patients who were to undergo CABG on a beating heart and had appropriate indications for surgery.However, the development of CVD and, in particular, CHD depends on many factors [9,10], including hereditary component, age, lifestyle, eating behaviour, stress, bad habits (smoking and alcohol consumption), elevated blood pressure and heart rate, comorbidities (hypertension, T2D, cardiac arrhythmias, overweight and obesity), which synergistically affect not only the development of CHD but also its course [10,11].

Conclusions
Based on the current understanding of the risk factors for CHD and the prevalence of all CVDs, it is necessary to take into account the impact of comorbidities such as T2DM, which is often present in patients of cardiac surgery centres.The presence of T2DM obliges doctors to identify difficulties during surgery and rehabilitation of this group of patients.An analysis of the incidence of T2DM in patients with coronary artery disease who were to undergo CABG on a beating heart showed that T2DM was detected in every 4th of them, exceeding the average population prevalence by 2.5 times.The annual reports of the International Diabetes Federation and numerous scientific studies on T2DM prove that this disease is extremely common and creates an additional risk of developing coronary heart disease in the general population, as well as significantly complicates its course.A statistical analysis of the prevalence of T2DM revealed that in the cohort of patients proposed for CABG on a beating heart, T2DM is statistically significantly more common in women with two and three or more CAD lesions.
Financing.Budgetary.This study was performed within the framework of the applied research work "Development and implementation of a system for preventing complications and improving the effectiveness of surgical treatment of coronary heart disease in high-risk patients", state registration number 0120U103769.
Authors' contributions.Sas S. S. -design, collection and processing of material, writing the text and preparing it for publication; Rudenko S. A. -formulation of the concept, conclusions.
Competing interests.The authors have no conflict of interest.
Consent for publication.All authors approved the paper to be published.