High cholesterol and COVID-19: what’s the connection?

Cholesterol is a waxy, fatty substance in your body. It’s important for things like making cell membranes and producing certain hormones and vitamins.

Experts have observed changes in cholesterol levels in people with COVID-19. Specifically, LDL-C, HDL-C, and total cholesterol levels drop when a person has COVID-19.

According to a research paper 2022, various other viral, bacterial and parasitic infections can lead to similar results. Here are some examples of other viruses that can cause changes in cholesterol levels:

Experts currently do not know how COVID-19 causes cholesterol levels to drop. Overall, experts believe that increased inflammation during infection influence various pathways associated with the production, transport and metabolism of cholesterol in the body.

With COVID-19, the magnitude of a drop in cholesterol levels may be related to the severity of the disease. A research report 2022 found that upon admission to hospital, people with severe COVID-19 had lower levels of:

• total cholesterol
• LDL-C
• HDL-C

According researchers, HDL-C has anti-inflammatory and anti-thrombotic properties. It is therefore possible that a sharp drop in HDL-C during COVID-19 could increase the risk of problems due to high levels of inflammation and blood clots.

Although cholesterol has important functions in the body, too much of it can be harmful. When there is too much cholesterol in your blood, you usually have high cholesterol.

The Centers for Disease Control and Prevention (CDC) estimate that approximately 38% of adults in the United States have high cholesterol. As such, you may be wondering if high cholesterol increases your risk of contracting COVID-19.

Currently, high cholesterol is not on the CDC list of conditions that increase the risk of COVID-19. However, several conditions that often occur with high cholesterol include:

High cholesterol can increase your risk of getting COVID-19

A study 2021 found that higher body mass index and cholesterol were linked to COVID-19 cases and deaths.

The researchers suggested the finding may be one of the reasons regions of the world with a high prevalence of obesity and high cholesterol have seen more COVID-19 cases and deaths.

Another one study 2021 used data from the UK Biobank to examine the effect of cholesterol on susceptibility to COVID-19. After their analysis, the researchers found that higher total cholesterol levels were linked to increased susceptibility to COVID-19.

How does high cholesterol increase your risk?

Cholesterol is present in the membranes of cells in the body. As such, it is possible that higher cholesterol increases susceptibility to COVID-19 by promoting viral entry into host cells.

A study 2021 studied this idea. In one lab, experts loaded cell membranes with a blood-derived cholesterol supplement. Experts exposed cell membranes to a test virus with the spike protein of SARS-CoV-2, the virus that causes COVID-19. The researchers found that infection was higher in cholesterol-laden cells.

They suggested that since the virus infects cells with higher cholesterol more efficiently, this may add another reason why COVID-19 may be more severe in older people, as they may be more likely to have underlying medical conditions like high cholesterol.

High HDL-C may protect against COVID-19

A study 2022 also looked at the effect of cholesterol level on the risk of developing COVID-19. The researchers found that high levels of HDL-C were linked to a lower risk of contracting COVID-19.

Experts have found the lowest level of risk in people with high levels of HDL-C and low levels of LDL-C.

Unlike the other studies discussed, other types of cholesterol, such as total cholesterol and LDL-C, were not independently associated with the risk of developing COVID-19.

Long COVID is a collection of symptoms that can last for weeks, months, or even years after contracting COVID-19. People with long COVID can experience a wide variety of symptoms. Here are some examples :

Having COVID-19 can change cholesterol levels. But do some people continue to have altered cholesterol levels even after recovering from COVID-19?

A study 2021 follow-up of people who came to the hospital for COVID-19 after 3 to 6 months. Compared to their levels at admission, LDL-C and HDL-C levels improved significantly at the follow-up appointment.

Having high cholesterol may actually increase your risk of long COVID as well as prolonged symptoms of other non-COVID illnesses. At least, that’s according to a 2022 study.

The study involved people with a wide range of COVID-19 severity, from asymptomatic individuals to those with long COVID. It also included people who tested negative for COVID-19 but had prolonged COVID-like symptoms.

The researchers looked at different blood biomarkers. Unhealthy lipid levels, including cholesterol, linked to longer duration of symptoms for those who had tested positive for COVID-19 and those with other similar illnesses.

COVID-19 vaccines can be great tools to prevent serious illness and death from COVID-19. However, given the information about COVID-19 and cholesterol, you might be wondering if the COVID-19 vaccine can impact cholesterol levels as well.

There is currently a 2021 case report of altered lipid levels after vaccination. In it, a person experienced elevated triglyceride levels after receiving their second dose of the Pfizer-BioNTech vaccine.

However, the problem is that this individual suffered from an inherited condition called familial hypercholesterolemia, in which LDL-C levels rise dramatically.

There is currently no evidence that the COVID-19 vaccine impacts cholesterol levels in the general population.

COVID-19 can cause cholesterol levels to drop. The magnitude of this decline is related to the severity of the disease. Most people’s cholesterol levels rise again after recovery.

Having high cholesterol can increase your risk of getting COVID-19 and having long COVID. As such, consider taking steps to prevent illness, such as staying up to date on your COVID-19 vaccines.

High cholesterol levels can increase the risk of cardiovascular disease, which can have serious consequences, such as heart attack and stroke. If you have high cholesterol, see your doctor to manage it.