Correlation between plasma homocysteine and ischemic heart disease in young Adults

Introduction

Cardiovascular events account for one-third of all the fatalities worldwide. Heart disease and stroke kill more than 600,000 people per year in industrialized nations, such as the US. Deaths caused by cardiovascular diseases are most often caused by ischemic heart disease.¹ Atherosclerosis, the hardening and constriction of the coronary arteries that carry blood and oxygen to the heart, is a defining characteristic of ischemic heart disease. Coronary angiography is the most reliable method for diagnosing coronary artery disease is coronary angiography.² Figure 1 shows the diseases associated with ischemic heart disease. The etiology and course of atherosclerotic cardiovascular disease remain unexplained by established risk factors according to recent observational studies. Furthermore, 30% of individuals who present with myocardial infarction do not exhibit any of these risk factors.³ An increasing number of studies point to atherosclerosis as an inflammatory disease and blood inflammatory biomarkers as potential cardiovascular disease CVD predictors.⁴ By lowering the levels of antithrombotic factors and endothelial-derived nitric oxide and boosting the levels of prothrombotic factors XII and V, homocysteine accelerates atherosclerosis. Since its discovery in 1932, homocysteine has been a subject of much speculation. The term homocysteine comes from the fact that its chemical characteristics are comparable to those of cysteine as shown in Figure 2.⁵ People naturally possess the amino acid homocysteine (Hcy), which is a thiol group containing amino acids. Two metabolic processes break down Hcy in the body, and the kidneys remove a small amount as waste. Folic acid and vitamins B6 and B12 are required for the chemical processes that break down Hcy. Therefore, the presence or absence of these vitamins affects serum total Hcy levels. Several medical conditions, including occlusive artery disease (particularly in the brain, heart, and kidney), venous thrombosis, megaloblastic anemia, osteoporosis, depression, Alzheimer’s disease, and pregnancy complications are associated with hyperhomocysteinemia (HHcy) and homocystinuria. High HCY levels are associated with a range of diseases in both children and adults.⁶ Deficits in vitamin B6, folate, and B12, or by administering foods rich in Met. Furthermore, many medicines, including lipid-lowering and anti-Parkinsonian medications, might increase Hcy levels when used in clinical practice. Folate, vitamin B6, and vitamin B12 supplementation have been demonstrated to lower Hcy levels in studies, but whether they also reduce some related diseases is still under debate.⁷ In 1933, Vincent du Vigneaud was the first to isolate Hcy from urinary bladder stones (s). At about the same time, a 4-day evaluation was conducted on an 8-year-old child of Irish-American descent hospitalized at Mass General Hospital for symptoms such as headache, vomiting, lethargy, indicators of abnormal mental development, and dislocated lenses in both eyes. There was a marked decline in the health, and he showed symptoms of stroke, including left-sided paralysis and aberrant reflexes. In addition, the boy’s temperature and blood pressure increased, but there were no outward symptoms of infection. He died from the disease a few days later. This case was published in the New England Journal of Medicine in 1933 as case 19,471. The cause of death was arteriosclerosis of the carotid artery with cerebral infarction.⁸ Over the past 20 years, there has been heated discussion between academics and doctors regarding the significance and consequences of increased plasma Hcy levels in pathology. The traditional view of folate’s causative function in pathogenesis has been cast into doubt by the finding that its treatment reduces plasma Hcy levels, but has no discernible effect on the course or outcome of illness. Research into homocysteine homeostasis is ongoing on a global scale because of its potential role as a cause, mediator, biomarker, and innocent bystander in neurological and cardiovascular illnesses.⁹ Methionine was heated with sulfuric acid to produce the desired amino acids. An increase in homocysteine levels has been associated with an increase in inflammation and oxidative stress in vascular endothelial cells as well as a decrease in endothelial nitric oxide production and bioavailability. Strong evidence suggests that oxidation plays a role in the process linking increased Hcy levels to atherosclerosis. To highlight the significance of this finding, it is necessary to mention that Vincent du Vigneaud was awarded the Nobel Prize in Chemistry in 1955 “For his work on biochemically important sulfur compounds, especially for the first synthesis of a polypeptide hormone”.¹⁰ In addition to causing occlusion or constriction of capillaries, hyperhomocysteinemia inculcates direct damage to endothelial cells, which in turn causes hyperplasia of smooth muscle cells. Elevated homocysteine levels in the blood are positively associated with hypertension and an increased risk of cardiac complications. Higher blood homocysteine levels are associated with an increased risk of aspirin resistance. Because of this, many people believe that homocysteine is its own risk factor for coronary artery disease. While the vascular toxicity of hyperhomocysteinemia is well established, there is a lack of data on how it alone affects coronary artery disease in younger people, devoid of the combined and synergistic effects of other traditional risk factors.¹¹

Figure 1. Ischemic heart disease: a schematic depicting the pathophysiological mechanisms.¹²

Figure 2. Structure of homocysteine.¹³

Methods

A total of 80 people were involved, with 40 serving as patients and 40 as controls. We included all cases and controls in the study who were either younger than 40 years or older than 25 years. Forty people served as controls and had no ischemic heart disease. The 40 patients served as cases with coronary angiographic evidence of moderate-to-severe stenosis in one or more main coronary arteries. A Performa was framed, and all relevant information of each performa was recorded. The procedure was described to the patient and written consent was obtained. A universal sampling technique is used for this purpose. To create a control group for comparison with the patient group, members were randomly selected from the general community. Both groups included patients of varying sex, ethnicity, geographical location, and socioeconomic status in their respective studies. Criteria for exclusion: Patients who were chosen for the study did not have any history of diabetes, myocardial infarction, angina, or autoimmune diseases, and they did not take any steroidal anti-inflammatory drugs or receive treatment for cancer. The two sets of patients were as follows.

Extraction was performed immediately after venous blood was collected from the participants’ forearms. Separated from the cycles of freezing and thawing, the specimens were kept at -20°C. Before centrifuging the mixture for 20 min, serum was left to coagulate. Ther liquid was then collected. Statistical Package for the Social Sciences (SPSS) was used for statistical analysis. Version 23 was updated. Data are presented as mean values with or without standard deviation (mean ± SD). The T test was used to compare parameters across the various study groups. In this study, to be considered statistically significant, the p-value must be less than or equal to 0.05. This study utilized the Human Homocysteine (Hcy) ELISA Kit.

Result

The participants in the case group had a mean age of 31.12±4 years and 40 participants in the control group had a mean age of 33.35±4.5 years. In the case group, there were 24(60%) males and 16(40%) females, while in the control group, there were 26(65%) males and 14(35%) females with a significant association between case and control and sex.

Regarding age distribution, the majority of cases in group 17(42.5%) were between 25-29 years, 15(37.5) were between 30-34 years, and 8(20%) were between 35-39 years. In the control group, 17 patients (42.5%) were between 35-39 years, 12(30%) between 30-34 years, 8(20%) between 25-29 years, 2(5%) ≥ 40 years, and only 1(2.5%) between 20-24 years as shown in Table 1.

The mean homocysteine level in case group was 40.21±14.47 mmol/L and 9.23±2.41 mmol/L in control group with p value <0.001 as it shown in Table 2.

The mean serum triglyceride levels in the case group were 118.42±14.145 mg/dl while 121.11±14.616 mg/dl in the control group (p = 0.412), as shown in Table 3.

The mean serum cholesterol level in the case group was 141.47±24.565 mg/dl, while in the control group was 156.31±19.017 mg/dl (p = 0.004), as shown in Table 4.

Regarding the homocysteine level and its association with sex, 20(50%) of male and 10(25%) of female had intermediate homocysteine levels, while 4(10%) of male and 6(15%) of female had mild homocysteine levels, as shown in Table 5.

Discussion

The primary goal of the current investigation was to determine the function of homocysteine in cardiovascular disease. Although there have been significant attempts to lower the mortality rate of cardiovascular illnesses in recent decades, effective prevention and treatment strategies have not met expectations, especially for high-risk individuals.¹⁴ Consequently, new risk factors for coronary artery disease (CAD) and their prevention have become the primary focus of contemporary research. Myocardial infarction (MI), heart failure, and stroke are outcomes of atherosclerosis, the most prevalent underlying pathology. When the arterial intima is continuously damaged by inflammation, it leads to arteriosclerosis, which is characterized by increased permeability to plasma, fibrosis, calcification of plaques, and deposition of plasma lipids. The idea that atherosclerotic disease is linked to high homocysteine levels was originally proposed more than 40 years ago because of the atherothrombotic mechanism that causes endothelial dysfunction. According to multiple studies, patients’ risks of cardiovascular disease and death are enhanced by 10% when their homocysteine levels are high. The main conclusion of this study was that hyperhomocysteinemia increases the risk of coronary artery disease (CAD) and myocardial infarction (MI) in the adult Iraqi population. Our findings demonstrated a markedly elevated homocysteine concentration in patients with myocardial infarction compared to healthy controls, suggesting a robust correlation between hyperhomocysteinemia and cardiovascular disease and its consequences, such as myocardial infarction. This confirms previous research linking elevated homocysteine levels to an increased risk of coronary heart disease in individuals who have suffered acute myocardial infarction. Further evidence linking homocysteine levels to an increased risk of coronary artery disease was found in research conducted by Schaffer and Al-Obaidi.^15,16 There is substantial evidence that increases in homocysteine cause damage to endothelial cells, decrease vascular flexibility, and alter the hemostasis process. Research has shown that high homocysteine levels are a cause of coronary artery disease (CAD), and other studies have shown that this new atherogenic risk factor might be a consequence of preclinical vascular illnesses. Traditional risk factors for coronary artery disease (CAD), such as hyperlipidemia, smoking, hypertension, and inflammation, may be amplified by high homocysteine levels. Research¹⁷ found no association between hyperhomocysteinemia and coronary artery disease (CAD) in individuals devoid of hypertension, diabetes, and dyslipidemia. Recent research in the Middle East, particularly in the Kurdistan region and Iraq, has examined the association between blood total homocysteine levels and coronary artery disease (CAD), but has failed to identify any effects on other risk factors for cardiovascular disease. A study conducted by Al-Gazally et al. corroborated these findings¹⁸ by investigating the prevalence of homocysteine in the Iraqi population and found that it was significantly higher in the groups affected by ischemic stroke and myocardial infarction, suggesting that it may serve as a standalone risk factor for coronary artery disease (CAD). Multiple Iranian studies¹⁹ demonstrated that elevated homocysteine levels are a distinct determinant of an increased risk of coronary artery disease (CAD), as greater serum homocysteine levels were detected in patients with abnormal angiography than in the control group. Our findings demonstrate that pure hyperhomocysteinemia, in the absence of traditional risk factors, can have a harmful effect on the cardiovascular system, even in the absence of other risk factors. The results demonstrated that regardless of whether the patient had one or more main coronary arteries narrowed to a moderate to severe degree, all young patients with coronary artery disease had elevated homocysteine levels in their blood. It is critical to address hyperhomocysteinemia immediately, because it is a controllable risk factor. Reducing cardiovascular morbidity and mortality can be achieved through primary and secondary prevention efforts by focusing on this area.

Conclusion

Hyperhomocysteinemia increases the risk of cardiovascular thrombosis in younger patients with coronary artery disease. Recent evidence points to increased homocysteine plasma concentration as a novel, preventable risk factor for atherosclerotic vascular disease. There are several ways in which an increase in homocysteine concentration can cause vascular alterations, according to the available experimental data. More research is needed to put these results into context.