Dyslipidemia is a specific term that people tend to confuse with high cholesterol. This is not entirely true, keep reading to find out.
The global prevalence of dyslipidemia and particularly in the United States, is explicitly enormous. The estimation is that it affects nearly half of the US population. This is an alarming situation, in light of the association between dyslipidemia and cardiovascular disease.
In this article, there would be the most up to date information about dyslipidemia. It will include several questions people tend to ask themselves, and now they are going to get an answer from a doctor’s perspective.
What is a lipid and how is their metabolism?
Firstly, I must explain to you what is a lipid, which one of them is in the blood, and what is their function in the body.
A lipid is a molecule that does not simply dissolve in water; this is essential because it allows them to fulfill most of their roles in the body. The main functions of them comprise storing energy, communication between cells, and providing most of the cell surrounding structure.
Here we are going to focus more on three specific molecules, although the existence of way more of them. There are “fat” molecules that stand for triglycerides. Then, there are fatty acids ( tri-, di-, monoglycerides, and phospholipids), and cholesterol (molecules that contain the “sterol”).
The body transports these molecules by particular a protein called “lipoprotein.” These have a division based on their density:
- Very low-density proteins (VLDL).
- Intermediate density protein (IDL).
- Low-density lipoproteins (LDL).
- High-density lipoproteins (HDL).
Chylomicrons are very large, and they are formed in the intestines carrying dietary triglycerides and cholesterol to the liver and tissues.
Then, VLDL is synthesized in the liver because of chylomicrons degradation by the enzyme lipoprotein lipase (LPL) that takes out triglycerides from it. Similarly, the remnants of VLDL after this process all over again produces the IDL.
The liver clears most of the IDL, but the remnants of it, also due to triglycerides removal covert into LDL. Notably, in this process, enzymes remove triglycerides, so each resulting lipoprotein has a higher cholesterol proportion than its predecessor.
LDL is circulating in the blood, and its removal from it, among many other factors, depends on an LDL receptor (LDLr).
On the other hand, HDL is formed on tissues (not in the liver or intestine). And it contains specifically apoA, in contrast to al previous ones which contain apoB.
Is dyslipidemia the same as high cholesterol?
No, dyslipidemia strictly speaking stands for an abnormal amount of lipid levels in the blood. This situation comprises an increase or decrease of it, and it could be solely a lipid or many at the same time.
On the other hand, high cholesterol only pertains to blood cholesterol levels without taking into account many other factors. And, as you will see, multiple other lipids matter as much as LDL cholesterol level. So, high cholesterol is dyslipidemia, while dyslipidemia embarks many other disorders also.
Dyslipidemia typically comprises high serum triglyceride levels and/or LDL, plus decreased levels of HDL cholesterol. Importantly, LDL and HDL levels regulate the amount of total cholesterol in the body. HDL is the “good” cholesterol that carries cholesterol molecules from the tissues to the liver for posterior excretion of the body. So, an imbalance of them leads to high cholesterol levels.
Furthermore, the triglyceride level in blood besides LDL and HDL also represent an entity capable of causing cardiovascular diseases. Therefore, each lipid should be lookout closer when people have dyslipidemia.
What is the difference between hyperlipidemia and dyslipidemia?
Dyslipidemia comprises an imbalance of lipid levels in the blood, which includes either an increase or a decrease of them. An example of a decrease would be hypocholesterolemia.
On the other hand, hyperlipidemia would be a specific scenario of dyslipidemia where there is an increase in lipid levels.
Hyperlipidemia could be an increase in blood cholesterol levels. This situation exists due to a rise in the LDL and a decrease in HDL cholesterol levels. Other forms of hyperlipidemia include isolated high triglyceride levels, or mixed in which both triglyceride and cholesterol levels are high at the same time.
What are the risk factors for dyslipidemia?
Several risk factors are in association with developing dyslipidemia. Sadly, some of them can be modified, and others not.
Modifiable risk factors, which also account for metabolic syndrome, include:
- Diet high in saturated or trans fat (fried food f.e.)
- Having minimal physical activity.
- Smoking habit.
Disease that cause the LDL cholesterol to raise:
- Biliary obstruction. (liver disease)
- Kidney disease.
- Type 2 diabetes mellitus.
Medications that can raise LDL cholesterol level:
Furthermore, the ones not subjected to any modification are the inherited sources of dyslipidemia—the ones we carry in our family.
Genetics plays a major in high cholesterol. Familial hypercholesterolemia is the result of an impairment of the LDLr, hyper functionality of PCSK9 protein, or lipoprotein mutations (for example, ApoB).
Of those three possibilities, the most common is the impairment of the cholesterol receptor or LDLr. This situation results in a decrease in the cholesterol clearance activity in the body, ending in high levels of this lipid.
Two types of familial hypercholesterolemia exist, homozygous and heterozygous. The latter is more common, affecting approximately one in every 500 people. And, it is in association with LDL cholesterol of 200 to 450 mg/dL. Typically these patients will develop the cardiovascular disease before the sixty years.
The homozygous form is rarer. It affects one in 300,000 to 1,000,000 people. Here, the LDL is way higher than in the other form reaching a cholesterol level beyond 450 mg/dL that could reach 1000 mg/dL and more. If it does not receive treatment, patients could have complications by the age of twenty.
As you can see, not all people with obesity would have high cholesterol levels. And not all people with low weight are safe from lipid impairment. Therefore, it relies on many factors, including genetics, lifestyle, diseases, and medication.
Can your lack of sleep cause you to have high cholesterol?
This question is tricky. For now, let us say “yes” to that question, but this has a whole explanation that backs up in several studies. Let me thoroughly explain it.
Regular sleep duration is between six and eight hours of sleep. Below and above, would be short and long sleep duration, respectively.
Anything that is not a regular sleep is in association with many lousy outcomes, and that goes equally for short and long sleep durations. Also, this applies too for people with insomnia symptoms.
Furthermore, Patients with these characteristics of no regular sleeping have a higher risk of:
- High waist circumference.
- High blood pressure.
- Low HDL blood levels.
- High triglycerides.
- An increase in LDL cholesterol and total cholesterol.
- High fasting blood sugar.
- High C reactive protein ( a body inflammation marker in blood).
So, what does this tell you? Well, sleep disorders, in general, have a link to insulin resistance, which is in relation to dyslipidemia. Therefore, to high LDL cholesterol and triglyceride levels, plus a decrease of HDL in the blood.
What causes dyslipidemia?
Anything that impairs lipid metabolism will end up in dyslipidemia. So, let us review some essential elements and explain the most common causes of it.
Insulin resistance plays a leading role worldwide, causing dyslipidemia. People that gain weight because of their diet occur mostly due to high-calorie consumption. They suffer changes within their fatty tissue. It becomes unhealthy.
Furthermore, hyperinsulinemia (insulin resistance) is the most common metabolic disorder among obese people. And the critical element for developing what is known as “metabolic dyslipidemia.”
Insulin hormone functions as a suppressor of the liberation of free fatty acids to the blood. A process that is usually occurring within the fat tissue. Also, it stimulates the degradation of the lipoprotein rich in triglyceride and activates the liver to produce cholesterol. When there is resistance to its function in the fatty tissue, it will end on a lipid disorder. This ailment characteristics are:
- Higher blood triglyceride levels.
- Damaged HDL or decreased.
- Small and dense LDL molecules (the ones with the highest capability of causing damage)
Diabetes that comprises either a lack of production or function of the insulin hormone is even better at causing dyslipidemia. The liver would not be able to receive any of the lipoproteins. Therefore, VLDL, IDL, and LDL will persist in the blood for more extended periods. Also, the lack of insulin promotes a state in which there is a constant releasing of fatty acids by the fat tissue that the liver receives. It could end in liver disease.
Besides, it cannot be forgotten the genetic cause of the disease as familial hypercholesterolemia. Here most of the time is because of LDL receptor impairment, which is inherited from the parents and will end in a high LDL level
Can dyslipidemia cause hypertension?
Hypertension and dyslipidemia are frequently found together, to the point that both of them contribute to atherosclerosis formation; that, in the end, will lead to cardiovascular disease.
However, the question here is another one. If dyslipidemia is capable of causing hypertension? Well, it makes sense, plus some studies support that.
A study in Tokyo, Japan, brought some interesting results concerning this topic. The conclusion of them comprises that patients with alteration in their lipid levels were keener to develop hypertension in the long run. It includes:
- HDL cholesterol, either too high or too low.
- High LDL.
- High triglycerides.
Furthermore, it will be interesting for us to discuss why they are so closely related? Well, dyslipidemia and hypertension are pretty good, damaging the blood vessels. The outcome for that will be atherosclerosis.
Accordingly, not only high cholesterol causes atherosclerosis, but the intense pressure that hypertension causes to blood vessels similarly contributes to that end. It is important to note that atherosclerosis is also a risk factor for developing hypertension.
Their relationship will have a thorough explanation right on the next question about how dyslipidemia leads to atherosclerosis. Therefore, overall, how it leads to cardiovascular diseases.
How does dyslipidemia lead to atherosclerosis?
Atherosclerosis is the primary cause of heart disease and stroke. Several conditions can lead to it, such as hypertension, dyslipidemia, diabetes, and obesity. This situation is possible because all of them can prompt damage for atherosclerosis development.
What is necessary to cause atherosclerosis? Three stages are essential to have this condition, such as oxidative stress, blood vessel wall damage, and chronic inflammation.
People with dyslipidemia that develops atherosclerosis receives a specific name for it, atherogenic dyslipidemia. In this situation, it is pretty common to find a particular cell called “macrophage” within the wall of the blood vessel. Also, this atherosclerotic process will occur in the blood vessel section, where there is more inflammation, like the branching points of the arteries.
Furthermore, these cells will be embedded with cholesterol causing it to produce more inflammation and damage within the blood vessel. Besides, it is typical in patients with dyslipidemia to have a stress oxidative state in which there is direct blood vessel wall damage that contributes to atherosclerosis.
The outcome of all these processes is pretty clear. There is damage to the blood vessel wall due to oxidative stress, among other causes. Later, thanks to a breach within the artery wall. It will exist a direct deposit of the LDL cholesterol inside the blood vessel wall. The macrophages will ingest that LDL cholesterol and turn into an unhealthy cell that will similarly encourage inflammation. This situation will become a vicious cycle that only gets worse and progress over time.
Finally, in atherosclerosis, there is a plaque formation within the blood vessel that causes a narrowing of the arteries (see the image below). This situation makes a person susceptible to further developing high blood pressure, which also contributes to atherosclerosis expansion.
Can dyslipidemia cause diabetes? Or is dyslipidemia a complication of diabetes?
This question is fantastic because it allows us to embark again on many of the terms we just recently saw. Consequently, be prepared to refresh your memory.
First, let me give you the answer. For now, the evidence suggests that insulin resistance is the trigger of dyslipidemia, and not high blood glucose (diabetes). However, it is essential to note that insulin resistance also plays a leading role in causing prediabetes, diabetes, and metabolic syndrome.
In the three of them, it would be possible to find dyslipidemia, even when there is no rise in the sugar blood yet. Hence, all the scientific community has turned their faces towards insulin resistance, rather than high glucose in blood states, for explaining the lipid disorder.
Importantly, insulin resistance is the first step in people with prediabetes or when the blood sugar has not even increased yet.
This scenario is the same for patients with metabolic syndrome, which have an insulin resistance state. Also, for people with diabetes, insulin resistance only progresses and gets worse. Therefore, dyslipidemia here could get even more detrimental.
It is pretty common to find patients with diabetes that also has dyslipidemia, for that the term diabetic dyslipidemia. And the problem is that both of them act together and potentiate atherosclerosis. Therefore, the likelihood of dying by cardiovascular disease increases. So, both of them need to receive treatment.
The conclusion could be that a lack of insulin or its function would end on both diabetes and dyslipidemia, independently or together; however, in these situations, which are pretty common in obese people. They are frequently found together playing a significant role in causing disease.
Is dyslipidemia a heart condition?
Dyslipidemia is not heart disease or condition. It is a metabolic disorder that tends to cause blood vessel or vascular disease, which ends up directly affecting the heart. Therefore, dyslipidemia is a disease that causes complications, and they are mostly found in this organ, among others.
Importantly as we just saw, dyslipidemia, among other diseases, plays a significant role in promoting and the progression of atherosclerosis, which is in direct relation to coronary artery disease, hence heart disease.
Atherosclerotic cardiovascular disease yields awful complications. Coronary artery disease could end on a heart attack (myocardial infarction) and overall heart dysfunction and illness.
A thorough description of the cardiovascular and other complications of dyslipidemia will be in the complications question.
How does kidney failure affect dyslipidemia?
Let us first clarify terms for answering this question. What is kidney failure? Which are the causes of kidney failure? What is chronic kidney disease? Then, I explain to you how it reaches to the point of causing dyslipidemia by an entirely different mechanism not discussed before in this article.
Kidney failure is when this organ cannot cope with its functions for any reason. This situation is terrible because the kidneys are the organs in charge of filtrating all the toxic molecules and wastes of the body, among many other functions. Interestingly, kidney failure could exist acutely and be reversible in some cases, or chronic.
Conversely, chronic kidney disease is when there is a constant and irreversible loss of kidney function. The causes for it are several, including dyslipidemia and other classical disorders as diabetes or hypertension.
Therefore, in this question, the referral would always be to a chronic kidney disease, which its progression leads to irreversible kidney failure, hence dyslipidemia, since chronic kidney disease interferes with the regulation of primary metabolic pathways, as we will see further.
Typically patients with chronic kidney disease will develop this lipid profile:
- Increased triglyceride in blood.
- Increased VLDL in the blood.
- Decreased levels of HDL.
- Variable levels of LDL.
Progressive renal failure, especially the one concerning protein loss through the urine, impairs lipid transport mechanisms in the body. This situation reflects on the lipid panel I just pointed you, but what is happening?
Several factors collaborate in this matter. Firstly, protein loss stimulates the liver to produce more LDL. There is an enhancement of the enzyme in charge of producing cholesterol, which causes high cholesterol levels. Secondly, there is an enzyme lost through urine that affects HDL function, and VLDL clearance (which is rich in triglyceride).
Does it have any signs or symptoms?
Most of the time, dyslipidemia will be a disease without any signs and symptoms, which is a situation to worry because most people are unaware of their condition.
The signs and symptoms that could exist are the ones from other diseases that frequently coexist or are complications of dyslipidemia, such as diabetes, hypertension, coronary artery disease, stroke, liver disease, and more.
However, some symptoms and signs could appear solely because of the high lipid level in the body. It mostly occurs in the genetic causes of high cholesterol, rather than the ones because of insulin resistance. It could be the following:
- Patients could manifest joint pain.
- Skin manifestations could be present as planar xanthomas (in the hand, elbows, buttocks, and knee).
- Tendon xanthomas (in the back of the hand and the Achilles tendon in the ankle).
The xanthomas are skin lesions that result from cholesterol accumulation in the skin. They could be present in several forms throughout the body. Also, it is not a disease, rather an expression of an underlying metabolic disorder. You can see how they look in the following images.
Can it cause complications?
Dyslipidemia can yield a lot of complications, either alone or in combination with other diseases. It includes disorders due to atherosclerosis and others like cancer. I will show you the most important ones.
Importantly, dyslipidemia is an essential link between obesity and the development of type 2 diabetes mellitus, cardiovascular disease, and certain types of cancer.
Furthermore, dyslipidemia alone is a cardiovascular risk due to its core participation in atherosclerosis development. This situation is real for the three most important manifestations of this disease, as can be hypertriglyceridemia (high triglyceride blood level), high LDL cholesterol, and low HDL cholesterol.
Each one of those elements alone has been found in relation to cardiovascular risk. Therefore, not only high cholesterol causes damage.
Typically, atherosclerosis of the heart arteries causes coronary artery disease. The occlusion of these essential blood vessels could end in catastrophic events like heart attacks (myocardial infarction).
Besides, when the atherosclerotic plaques are stable but growing. It will narrow arteries space for the blood flow in the long term, hence developing a coronary heart disease in which the heart chronically lacks sufficient oxygen. This situation can lead to heart insufficiency.
The other essential complications are stroke, peripheral artery disease, and kidney disease. Remember that dyslipidemia mostly causes vascular disease due to atherosclerosis. Therefore, all the major organs are a target of atherosclerosis. It can affect arteries in organs, such as the brain, heart, and kidney. Also, It could affect big blood vessels as the femoral artery, which diminishes the blood flow to the legs, hence causing disease.
How do you diagnose dyslipidemia?
The diagnosis of dyslipidemia needs a lipid profile that determines the specific lipid abnormality within the person. It will require the patient to fast from the previous night at least 12 hours, and then, a blood sample will be analyzed.
However, it is essential to highlight that a blood sample of a patient that is not fasting will only change the triglycerides analysis. While still the total cholesterol and HDL cholesterol because they do not significantly differ in people that just recently ate will be without meaningful modifications because of it. Therefore, in this condition, both of them are ready for analysis.
The laboratory tests include:
- Total cholesterol. (it is increased when above 200 mg/dL)
- LDL-C. (it is increased when above 160 mg/dL)
- HDL-C. (It is decreased when below 40 mg/dL)
- Triglyceride levels. (Normal less than 150 mg/dL, borderline high 150-199 mg/dL, high 200-499 mg/dL, and very high greater than 500 mg/dL)
Total cholesterol is the result of adding HDL, LDL, and 20% of the triglyceride levels. This talks about the overall cholesterol in the body. Also, these numbers are essential to calculate the cholesterol ratio.
Cholesterol ratio is a division of the total cholesterol number by the HDL number. It should always be below 5, with an optimal average number of 3.5 for males. For females, the maximum would be 4.4 and the average 3.3. The increase in this ratio above the limits is in association with cardiovascular complications.
Patients with a history of cardiovascular disease or high risk of having it, and possible familial hypercholesterolemia could benefit from these other measurements:
- Lipoprotein A.
- Apolipoprotein B.
- Apolipoprotein A1.
Similarly, people that have high cholesterol levels and within the range or slightly altered HDL and triglycerides are particular. The doctor would want to do further assessments because this situation highly suggests a genetic cholesterol disorder.
How do you treat dyslipidemia?
Firstly, people with lipid disorders should be encouraged to change their overall lifestyle regardless if medication is prescribed to them or not.
Solely by lifestyle modification, including physical activity and diet, can downplay LDL-C by 5 to 15%. This means that 14 to 5% of the population will no longer need medication.
Firstly, primary prevention is used in patients with high risk but no manifestations yet of atherosclerosis. Then, there is secondary prevention in which patients have overt signs of atherosclerosis.
Primary prevention is encouraged for all the patients at risk. First, these people will have changes to their lifestyle, and there is going to be a determination of their cardiovascular risk. In the end, if necessary, there will be an offering about lipid-lowering drug therapy.
On the other hand, the recommendation for secondary prevention is beginning statin therapy as soon as possible.
The statin is a type of drug that lowers lipids; in fact, it is the preferred among all. The primary function is to halt specifically the enzyme in charge of producing cholesterol in the liver.
Therefore, the statin removes cholesterol from the blood. To this day, statin solely (statin monotherapy) is the indication for most of the patients to lower total cholesterol.
However, for every rule, it exists an exception. There are some cases where patients are receiving maximum doses of statins and are not improving. In that scenario, it is possible to add another drug to potentiate the effect.
Is there an alternative to taking statins?
Yes, there are many other options besides the statin, although for now, not as effective. Also, the familial hypercholesterolemia can receive other special treatment. Let me show you.
The other drugs for lipids disorders include:
- Bile acid sequestrants.
- Omega-3 fatty acids.
Importantly, from all of them. Niacin has a double effect because it reduces the liver production of lipid molecules, plus it is the drug that most increases HDL cholesterol, up to 30%.
For patients with familial hypercholesterolemia is a different situation. They could have the worse elevations of cholesterol. Therefore, the disease most difficult to handle, even by drugs.
When the maximum dose of the statin is reached, many other options come to play. There are various, such as PCSK9 inhibitor, ApoB antisense oligonucleotide, and microsomal triglyceride transport protein inhibitor. The former has formidable outcomes in those patients requiring additional aid in lowering cholesterol levels.
How do you prevent dyslipidemia?
Dyslipidemia prevention mostly relies on lifestyle changes. It includes diet and physical activity. The essential here will be not only to prevent dyslipidemia, but the patient is preventing the cardiovascular (CVD) risk of it.
Overall, CVD risk is higher in people that do not have a healthy lifestyle because many disorders are in association with it, such as dyslipidemia, obesity, metabolic syndrome, diabetes, hypertension, atherosclerosis, and more.
For reading about a healthy diet and how much exercise is needed, please pass through the next two questions.
Does exercise increase HDL cholesterol in those who need it the most?
Regular exercise that is about 30 minutes per day for five days a week at a minimum intensity of brisk pace is beneficial. However, not alone.
People should also moderate alcohol consumption, smoking cessation, weight reduction. All of this, plus regular exercise, can increase HDL up to 10%.
What foods are not suitable to eat when you have high cholesterol?
The recommended diet includes the following:
- Whole grains.
- Olive oil.
- Canola oil.
- Low-fat dairy products.
- Fish rather than animal products.
The diet limits or not encourage the consumption of:
- Sugar-sweetened beverages.
- Red meat.
- Fried food.
What can I do if I have most of the risk factors?
This tool is a dyslipidemia symptoms checker. Its design uses the most up to date information, trying to englobe the most common risk factors for this disease.
Therefore, feel free to use it to determine how likely it is for you to have dyslipidemia. It is free, and it will only take a few minutes.