According to the findings of a recent study that was published in the journal Current Medical Research and Opinion, high levels of lipoprotein(a) were associated with repeated coronary heart disease events in elderly people.
A glycoprotein apolipoprotein and a low-density lipoprotein (LDL) structure make up the lipoprotein(a) structure. High levels of lipoprotein(a), according to recent research, contribute to atherosclerotic cardiovascular disease and aortic valve disease.
It is thought that lipoprotein(a) is a risk factor for cardiovascular disease and death that is comparable to LDL. As a result, patients may be less likely to experience cardiovascular events in the future if lipoprotein(a) levels are decreased.
A previous study with a 16-year follow-up conducted by the same researchers found a correlation between lipoprotein(a) levels and coronary heart disease among adults in Australia over the age of 60. There was a 45 percent increased risk in the first presentation of coronary heart disease in the top quartile of the distribution of lipoprotein(a). However, the connection between elevated levels of lipoprotein(a) and the possibility of recurrent cardiovascular disease has only recently been the subject of research.
In the current study, participants from the Dubbo study were invited to participate in a second study examining the relationship between elevated lipoprotein(a) levels and the risk of having the same coronary heart disease event multiple times.
For demographic, cardiovascular, and psychosocial risk assessments, baseline observations were recorded. Blood tests, anthropometry, a resting electrocardiogram, and blood pressure were some of the medical assessments that were carried out. After a 12-hour fast, blood samples were taken to measure the levels of glucose, lipoproteins, and lipids.
Prior angina or myocardial infarction—changes in the resting electrocardiogram that were recorded during the baseline measurements—were used to define prevalent coronary heart disease at the beginning of the study.
From hospitalization or death records and postal surveys that were carried out every two years to confirm the patient’s vital status, incident coronary heart disease events that might have occurred between the first and second studies were identified.
The levels of lipoprotein(a) were measured with a sandwich ELISA, a modified enzyme-linked immunosorbent assay (ELISA). The cholesterol content of lipoprotein(a) was also taken into account when calculating LDL cholesterol levels.
The independent association between elevated lipoprotein(a) levels and recurrent coronary heart disease was found using the Cox proportions hazard regression model.
The current study included 399 cases of coronary heart disease with median lipoprotein(a) levels of 130 mg/liter. In contrast, cases without recurrent coronary heart disease had median lipoprotein(a) levels of 105 mg/liter. Lipoprotein(a) levels differed slightly between people who had and did not have recurrent coronary heart disease.
Older age, male gender, low levels of high-density lipoprotein (HDL) cholesterol, and high levels of triglycerides were additional significant differences between those with and without recurrent coronary heart disease. Additionally, diabetes, atrial fibrillation, and antihypertensive medications were frequently utilized in recurrent coronary heart disease cases. Recurrent coronary heart disease patients did not have higher LDL cholesterol levels.
As a result of the highly skewed distribution of lipoprotein(a) levels, individuals with elevated levels were identified and their relative risk of coronary heart disease was determined using multivariate models.
To this end, for people with lipoprotein(a) levels higher than 300 mg/liter, the excessive relative risk was 37% when contrasted with people with lipoprotein(a) levels lower than 300 mg/liter. Essentially, for people with lipoprotein(a) levels higher than 500 mg/liter, the overall risk expanded to 59% when contrasted with those with lipoprotein(a) levels lower than 500 mg/liter.
Notably, this study did not find that the body’s LDL concentration after accounting for the 30% lipoprotein(a) derived cholesterol was a predictor of coronary heart disease.