High lipoprotein(a) levels linked to repeated heart disease events in older adults

In a recent study published in the journal Current Medical Research and Opinion, researchers report that high lipoprotein(a) levels were linked to repeated coronary heart disease events in older adults.

Study: Lipoprotein(a) and the risk of recurrent coronary heart disease: the Dubbo Study. Image Credit: SUWIT NGAOKAEW / Shutterstock.com

Background

The lipoprotein(a) structure consists of a low-density lipoprotein (LDL) structure attached to a glycoprotein apolipoprotein. Recent studies indicate that high levels of lipoprotein(a) contribute to aortic valve disease and atherosclerotic cardiovascular disease.

Lipoprotein(a) is believed to be a similar risk factor as LDL for cardiovascular disease and mortality. Therefore, by reducing lipoprotein(a) levels, patients may be at a reduced risk for future cardiovascular events.

A previous study by the same authors demonstrated the link between lipoprotein(a) levels and the occurrence of coronary heart disease among adults in Australia above the age of 60 years, with a follow-up of 16 years. Within the top quartile of lipoprotein(a) distribution, there was a 45% excess risk in the first presentation of coronary heart disease. However, only recently have studies examined the relationship between increases in lipoprotein(a) levels and the possibility of recurrent cardiovascular disease.           

About the study

In the present study, researchers invited the participants from their first study, known as the Dubbo study, to participate in the second study examining the association between elevated levels of lipoprotein(a) and the risk of repeated coronary heart disease events.

Baseline observations for demographic, cardiovascular, and psychosocial risk assessments were recorded. A range of medical assessments was performed, including blood tests, anthropometry, resting electrocardiogram, and blood pressure. Blood samples were collected after 12 hours of fasting to measure glucose, lipoproteins, and lipids levels.

Prevalent coronary heart disease at the onset of the study was defined as previous angina or myocardial infarction—resting electrocardiogram changes recorded during the baseline measurements.

Incident coronary heart disease events that could have occurred over the 16 years between the first and second study were determined from records for hospitalization or death and postal surveys that were conducted to confirm the vital status of the patient every two years.

A modified enzyme-linked immunosorbent assay (ELISA) called sandwich ELISA was used to measure the levels of lipoprotein(a). LDL cholesterol levels were also determined and corrected for the cholesterol content from lipoprotein(a).

The Cox proportions hazard regression model was used to determine the independent association between elevated lipoprotein(a) levels and recurrent coronary heart disease.

Study findings

A total of 399 cases of coronary heart disease with median lipoprotein(a) levels of 130 mg/liter were included in the current study. Comparatively, the median lipoprotein(a) levels in cases with no recurrent coronary heart disease were 105 mg/liter. The difference between the lipoprotein(a) levels of individuals with and without recurrent coronary heart disease was mildly significant.

Other significant differences between those with and without recurrent coronary heart disease included older age, male gender, low high-density lipoprotein (HDL) cholesterol levels, and high triglyceride levels. Additionally, many recurrent coronary heart disease cases used anti-hypertensive therapies, atrial fibrillation, or diabetes. LDL cholesterol levels were not higher in individuals with recurrent coronary heart disease events.

The distribution of lipoprotein(a) levels was highly skewed, which led to identifying individuals with elevated lipoprotein(a) levels and using multivariate models to identify their relative risk of coronary heart disease.

To this end, for individuals with lipoprotein(a) levels higher than 300 mg/liter, the excessive relative risk was 37% as compared to individuals with lipoprotein(a) levels lower than 300 mg/liter. Similarly, for individuals with lipoprotein(a) levels higher than 500 mg/liter, the relative risk increased to 59% when compared to those with lipoprotein(a) levels lower than 500 mg/liter.

Notably, the concentration of LDL after correcting for the 30% lipoprotein(a) derived cholesterol in the body was not a predictor of coronary heart disease in this study.

Conclusions

High levels of lipoprotein(a) were a risk factor for recurrent events of coronary heart disease among individuals above the age of 60 years. For individuals with lipoprotein(a) levels of 355 mg/liter or greater, the possibility of another coronary artery disease event was 53% higher.

While the impact of treatments that focus on lowering lipoprotein(a) levels to limit the incidence of recurrent coronary heart disease remains unclear, the current study reported that low-density lipoprotein levels did not predict the risk of recurrent cardiovascular events.

Journal reference:
  • Simons, L. A., & Simons, J. (2023). Lipoprotein(a) and the risk of recurrent coronary heart disease: the Dubbo Study. Current Medical Research and Opinion, 1–6. doi:10.1080/03007995.2023.2214434
Dr. Chinta Sidharthan

Written by

Dr. Chinta Sidharthan

Chinta Sidharthan is a writer based in Bangalore, India. Her academic background is in evolutionary biology and genetics, and she has extensive experience in scientific research, teaching, science writing, and herpetology. Chinta holds a Ph.D. in evolutionary biology from the Indian Institute of Science and is passionate about science education, writing, animals, wildlife, and conservation. For her doctoral research, she explored the origins and diversification of blindsnakes in India, as a part of which she did extensive fieldwork in the jungles of southern India. She has received the Canadian Governor General’s bronze medal and Bangalore University gold medal for academic excellence and published her research in high-impact journals.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Sidharthan, Chinta. (2023, June 18). High lipoprotein(a) levels linked to repeated heart disease events in older adults. News-Medical. Retrieved on October 06, 2024 from https://www.news-medical.net/news/20230618/High-lipoprotein(a)-levels-linked-to-repeated-heart-disease-events-in-older-adults.aspx.

  • MLA

    Sidharthan, Chinta. "High lipoprotein(a) levels linked to repeated heart disease events in older adults". News-Medical. 06 October 2024. <https://www.news-medical.net/news/20230618/High-lipoprotein(a)-levels-linked-to-repeated-heart-disease-events-in-older-adults.aspx>.

  • Chicago

    Sidharthan, Chinta. "High lipoprotein(a) levels linked to repeated heart disease events in older adults". News-Medical. https://www.news-medical.net/news/20230618/High-lipoprotein(a)-levels-linked-to-repeated-heart-disease-events-in-older-adults.aspx. (accessed October 06, 2024).

  • Harvard

    Sidharthan, Chinta. 2023. High lipoprotein(a) levels linked to repeated heart disease events in older adults. News-Medical, viewed 06 October 2024, https://www.news-medical.net/news/20230618/High-lipoprotein(a)-levels-linked-to-repeated-heart-disease-events-in-older-adults.aspx.

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Study uncovers hidden proteins fueling heart disease and stroke