Release Date: 01/16/2023 Episode Length: 01:18:54
3 Key Takeaways
Smoking, high blood pressure and elevated LDL cholesterol are the leading causes of heart disease
Measuring LDL and apoB in the blood is the best way to evaluate risk for heart disease
People should get evaluated for risk of heart disease in their 20's and make the lifestyle changes necessary to slow the onset of atherosclerosis, this may include taking medications
In this episode, Peter emphasizes the significance of comprehending cardiovascular disease and why early intervention is essential. He also gives a basic overview of lipoproteins and debunks the misconceptions of the terms "good cholesterol" and "bad cholesterol." Allan Sniderman talks about the measurements taken in routine blood tests and their limitations, before explaining why apoB is a superior indicator of risk. Furthermore, Tom Dayspring explains apoB's causal role in atherosclerotic cardiovascular disease (ASCVD) and the treatment goals for its concentration. Peter also describes how early and aggressive reduction of apoB levels could revolutionize the prevention of cardiovascular disease. Understanding Atherosclerosis
Atherosclerosis specifically refers to the build-up of fatty deposits (plaques) in the inner lining of arteries
These plaques can restrict blood flow, increase the risk of blood clots, and eventually lead to serious health problems such as heart attack, stroke, or peripheral artery disease
Atherosclerosis is an unavoidable disease that affects everyone eventually
It can be serious and even fatal in some cases, with over 50% of people's first heart attack being deadly
However, there are ways to reduce the risk of this condition and delay its onset
Women and men both get heart disease, but women usually experience it about 10 years later than men
About 1/3 of women will have a serious cardiac event (heart attack, stroke, or death) after age 65, for men the number is over 50%
Being aware at a young age can help prevent these events from happening earlier in life
Defining ASCVD and the Role of Cholesterol
Cholesterol is a type of molecule that is essential for the body's functioning
It makes up part of cell walls and is needed for hormones such as estrogen, testosterone, and cortisol
Atherosclerosis (ASCVD) occurs when too much cholesterol builds up on the artery walls instead of staying dissolved in the blood circulation
This buildup causes plaques that reduce the efficiency of the arteries by blocking the flow of oxygen to certain parts or organs of the body
The main consequence of ASCVD is an increased risk of heart attack, stroke, and peripheral artery disease (PAD)
Cholesterol is only found in animal products
Eating food with cholesterol does not necessarily increase the cholesterol levels in the bloodstream, but eating too much can still be harmful
Why Early Prevention of Atherosclerosis is Critical
Lifestyle changes such as diet, exercise and stress reduction are the best ways to reduce the onset of arterial disease
People who have family history of atherosclerosis should put more effort into healthy habits
Doctors prescribe statin drugs to help prevent atherosclerosis in patients who have an increased risk of getting heart disease
To predict who might get sick, doctors look at "10-year risks" based on factors such as age, sex and ethnicity
Cholesterol levels only have a small effect on these predictions (about a 4% chance)
However, even patients with low-risk numbers can still get sick before 60 years old, so looking only at 10-year predictions is not enough
Doctors should gather all the health information about their patients when deciding whether they need medicine or not
Patients should be treated differently based on their risk of getting an infarct or stroke, which is measured using a 'causal benefit model' that projects the risk over 20-30 years
The risk can change depending on the starting age (35, 45, or 55), and these changes can also be calculated
Lipids and Lipoproteins: Why there is no “Bad” or “Good” Cholesterol
Cholesterol is essential for life because it helps cells to be fluid
The liver produces more cholesterol than needed but other parts of the body may need extra during times of stress
Cholesterol cannot dissolve in water, so it is transported around the body with the help of lipoproteins (LDL and HDL)
Cholesterol is a type of fat in the blood and is measured in two forms: LDL and HDL cholesterol
Good and bad cholesterol is not an accurate term; what matters is what the particle size and function
The most important test for predicting heart disease risk looks at ApoB concentration as it includes all types of dangerous lipids
Don't worry about whether cholesterol is good or bad, just understand there are multiple variables that dictate risk for heart disease
Limitations of standard blood panels
Getting a report from the doctor is not always straightforward
Doctors get five different numbers, but they only need four of them:
Total cholesterol, LDL cholesterol (usually calculated), HDL cholesterol, VLDL cholesterol (estimated), and apoB
The key value that doctors look at is the LDL because it shows if someone has an increased risk of heart disease from too much fat in their blood
Triglyceride levels are also important because people with higher levels may be more likely to develop heart problems, but there is no evidence yet that it directly causes these issues
apoB as the Superior Metric for Risk Prediction
Mendelian randomization is a method of studying the relationship between genes and disease risk
Scientists use this approach to better understand causality in the link between certain genes and diseases, making the results more reliable than just observational data alone
The study of genes involved in disease risk helps scientists understand why some people get sick from certain diseases but not others
For example, scientists may look at genes related to cholesterol levels and their connection with heart disease risk factors such as high LDL-cholesterol and low HDL-cholesterol levels
Peter Attia emphasizes the importance of measuring both LDL-C and apoB levels to diagnose and treat patients at risk for serious illnesses, like heart disease and stroke
ApoB is a type of cholesterol that increases the risk of cardiovascular disease, and having too many apoB particles can lead to damage in cells and weaken protection against illness
Peter Attia believes there is no limit to the benefits of reducing apoB levels, and modern drugs make it possible to bring levels down to 20-40 mg/dL
He suggests reducing apoB levels by 50% as a first step for those with higher risks, then seeing if it can be reduced further without harm
How Early and Aggressive Lowering of apoB Could Change the Course of ASCVD
Smoking, high blood pressure, and high levels of lipoproteins (LDL, VLDL) are the main causes of ASCVD (atherosclerotic cardiovascular disease)
To accurately measure "bad" lipids, it is recommended to measure apoB instead of just LDL cholesterol numbers or particle numbers
If someone who is 40 years old has elevated apoB levels, it is important to lower it as soon as possible to reduce the risk of ASCVD
Lowering apoB levels further than previously suggested may help prevent deaths from atherosclerotic diseases, starting as early as age 20
It may be beneficial to give medicine to people with genetic abnormalities such as familial hypercholesterolemia when they are teenagers to prevent ASCVD.
A goal of having an apoB level lower than 60 by the late 30's or early 40's is recommended
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