Relationship between cholesterol and cardiovascular disease

Cholesterol and Heart Disease – What’s the Evidence? - Students 4 Best Evidence

relationship between cholesterol and cardiovascular disease

The sheer amount of of information about the relationship between cholesterol and risk of heart disease can be overwhelming and sometimes. Studies evaluating over 20 million subjects show an association between higher LDL and increased risk of heart disease. For some, that is. What is Cholesterol? How Does High Cholesterol Cause Heart Disease? What Are the Symptoms of High Cholesterol? What Numbers Should I.

Put simply, cholesterol is essential for life. Triglycerides are another type of fat found in your blood. Again, your body makes some triglycerides and some comes from the food you eat. Triglycerides are used for energy and any excess is stored as fat.

relationship between cholesterol and cardiovascular disease

High levels of triglycerides are associated with increased risk of cardiovascular disease. How is cholesterol moved around the body? Cholesterol is a fatty substance which cannot dissolve in blood like oil and waterso it is carried around by proteins.

relationship between cholesterol and cardiovascular disease

These fat lipo and protein complexes are called lipoproteins. There are two main types: This controls the amount of cholesterol in the blood. HDL can also act as an antioxidant. High LDL cholesterol causes cardiovascular disease If there is too much LDL cholesterol in the blood, it can deposit in the walls of the arteries giving rise to cardiovascular disease. What kind of research was this? It has long been thought that cholesterol is a key cause of the fatty build-up in arteries atherosclerosis that causes heart disease.

Dietary Cholesterol, Serum Lipids, and Heart Disease: Are Eggs Working for or Against You?

However, the researchers say there are contradictions to this view. Recent research has suggested that total cholesterol becomes less of a risk factor for all-cause or cardiovascular mortality the older people get. Less is known about LDL specifically and that's what this research aimed to look at. A systematic review is the best way of gathering evidence from cohort studies that have looked at the link between an exposure or risk factor and an outcome.

However, the strength of a review's findings is only as good as the studies they include.

relationship between cholesterol and cardiovascular disease

In cohort studies, it is often difficult to directly attribute an outcome to a specific cause, and there is always the potential that other factors are influencing the outcome. What did the research involve?

relationship between cholesterol and cardiovascular disease

The researchers searched one literature database PubMed in December to identify English-language cohort studies that had included a general population sample aged 60 and over. Studies had to have taken baseline measures of LDL cholesterol and then followed participants up over time, looking at the link with all-cause or cardiovascular mortality.

Three authors reviewed potential studies and extracted data. From an initial 2, hits, 19 publications, covering 30 cohorts and including 68, participants, were included. The majority of studies were excluded outright, as they didn't seem to contain anything relevant in the study title or abstract summary. The other reasons for exclusion were non-English language, participants not being representative of the general population, not measuring LDL cholesterol at baseline, and not giving separate data for older adults or looking at mortality outcomes.

Dietary Cholesterol, Serum Lipids, and Heart Disease: Are Eggs Working for or Against You?

What were the basic results? That is, as LDL cholesterol went down, all-cause mortality went up — higher LDL was apparently linked to lower all-cause mortality. In 14 of these 16, this was said to be a statistically significant link. The remaining 12 cohorts found no link with all-cause mortality. Only nine of the identified cohorts specifically reported cardiovascular mortality.

Does High Cholesterol Cause Heart Disease?

Seven found no link between LDL cholesterol and cardiovascular mortality. The other two found that those in the lowest fourth quartile of LDL levels actually had the highest cardiovascular mortality. How did the researchers interpret the results?

relationship between cholesterol and cardiovascular disease

The researchers concluded that, "High LDL-C is inversely associated with mortality in most people over 60 years". They said their finding contradicts the cholesterol hypothesis: They consider that as they found older adults with high LDL live just as long as those with low LDL, this "provides the rationale for a re-evaluation of guidelines recommending pharmacological reduction of LDL-C in the elderly".

However, before accepting this as fact, there are many important limitations to consider — both to the review and the included studies — many of which the review authors themselves acknowledge: There is the potential that many studies relevant to this question may have been missed out. The review searched only a single literature database, excluded studies only available in non-English language, and excluded studies where the title and abstract did not appear to contain information on the link between LDL and mortality in older adults.

The study only looked at the link in older adults aged over