Not long after the start of the global coronavirus pandemic, it was apparent that many people infected with SARS-CoV-2 were developing persistent and, in some cases, debilitating health problems. Now known widely as post-Covid syndrome or Long COVID, the most common symptoms of this condition are fatigue, attention problems, headaches, muscle or joint pain, and weakness. But those are just the start. Medical researchers have also linked SARS-CoV-2 to lingering complications in multiple organs and systems, and some recent work has found that new-onset cholesterol problems may be an under-recognized but common complication of COVID-19.
“We’ve been doing research on the long-term consequences of infection, and we see a lot of patients come in with fatigue, brain fog, and the other symptoms most people associate with Long COVID,” says Dr. Ziyad Al-Aly, director of the Clinical Epidemiology Center and Chief of the Research and Development Service at the VA Saint Louis Health Care System. “But we’ve also seen people who have never had any metabolic problems develop new-onset diabetes or hyperlipidemia, and so we decided to take a scientific and systematic look at the metabolic consequences of infection.”
In a study appearing in the January 2023 issue of the journal Lancet Diabetes and Endocrinology, Al-Aly and colleagues examined the health records of more than 150,000 users of the VA health system. They found that unvaccinated people who had been infected with SARS-CoV-2 were significantly more likely to develop high cholesterol and other unhealthy levels of blood fats than people who had not been infected. “What we found was a very clear signal that people who had had COVID-19 had a higher risk of cholesterol problems that included higher LDL, higher total cholesterol, higher triglycerides, and lower levels of so-called good cholesterol,” he says. “And these were all new events, meaning they were showing up in people who had no history of cholesterol problems.”
How common are these complications, according to his study findings? “Out of 100 adults infected with the virus, anywhere between one and four could end up with high cholesterol as a result,” he says. “That may sound small, but when you’re talking about billions of people who have been infected, this could translate to millions of people around the world having cholesterol problems that they did not have before.”
Al-Aly’s research isn’t the only work linking COVID-19 to cholesterol problems. Other high-quality studies have turned up the same connection. While many questions remain to be answered, experts who have examined this post-COVID phenomenon say it could present serious health risks to millions of Americans—but that there are things you can do to protect yourself.
More evidence of a connection
In August of 2022, the journal Lancet Infectious Diseases published a COVID-19 study focusing on unvaccinated Swiss military personnel. “Shortly after the pandemic started, the surgeon general of the Swiss Armed Forces asked for a study designed specifically to examine the impact of COVID-19 infection in young recruits,” says Dr. Patricia Schlagenhauf, principal investigator of the study and a professor in the Epidemiology, Biostatistics and Prevention Institute at the University of Zurich in Switzerland. The average age of the 501 participants in her group’s study was 21, and all of them were healthy enough to engage in military training. The researchers compared the health outcomes of those who’d had COVID-19 to those who hadn’t, and their analysis included metabolic, pulmonary, cardiovascular, reproductive, and psychiatric symptoms or conditions. “We were quite surprised to see that there was very little difference between the groups,” Schlagenhauf says. “But a couple of differences were significant, and one was that the group who had previously been infected had higher blood cholesterol, higher BMI, and higher LDL than the group who didn’t have any exposure to the virus.” In essence, her study turned up the same results as the VA study—albeit in a younger group of people and with different methods of testing.
How could COVID-19 cause cholesterol problems to develop in people who, prior to infection, had no sign of elevated blood lipids? “I can’t answer that,” Schlagenhauf says. “Some people have said maybe those who had COVID didn’t do as much exercise, or maybe they were more homebound and ate more, but I don’t think that’s the reason.”
While Al-Aly agrees that it’s impossible to say with certainty what might be causing the cholesterol issues in people who have had COVID-19, he says several plausible hypotheses have been proposed. “One of them has to do with microbiome dysbiosis,” he says. The human oral and gastrointestinal tracts are populated by trillions of bacteria that assist in various metabolic processes, including the breakdown and absorption of food molecules. “If, following infection, the microbiome is disturbed, this could lead to metabolic disturbances including higher cholesterol,” he says. In support of this hypothesis, several studies have shown that COVID-19 can disrupt the composition of the human microbiome, and people who develop these post-infection microbiome disruptions may be at greater risk for Long COVID complications.
“Another hypothesis,” he says, “is that the virus might persist in the body—not the full live virus but fragments of it—and this could cause low-grade chronic inflammation that could disturb the regular metabolic machinery.” In this scenario, he says the virus might not be detectable with standard tests, and yet the pieces of the virus that remain could create “a chronic-stress kind of situation” where the body hoards calories and converts those into lipids. This could lead to high cholesterol, high triglycerides, and the other metabolic complications his study turned up. Here again, some research on Long COVID (and other types of post-viral syndromes) has found that even after all live and infectious parts of a virus are cleared, fragments of viral genes may continue to influence the body’s metabolism or immune functioning in ways that could cause ongoing health problems, including high cholesterol.
Read More: How to Lower Your Cholesterol Naturally
Many unanswered questions
The evidence that SARS-CoV-2 can cause new cholesterol problems is compelling. However, it’s unclear whether these cholesterol problems are permanent or temporary.
“We were looking at people more than six months post-COVID,” Schlagenhauf says. She and her group are planning follow-up research featuring the same study participants—work that should provide important data on the durability of Long COVID symptoms and complications, including cholesterol problems. But, as of right now, she can’t say whether the blood-lipid issues her study identified will linger indefinitely. Al-Aly says much the same of his group’s work (although in his paper, the cholesterol problems were still present a full year after infection).
Also unclear: whether SARS-CoV-2 was the sole cause of the new-onset health problems observed in these research studies. Al-Aly says some people may have been headed for cholesterol problems even if they had not contracted SARS-CoV-2. “We found that the risk of developing hyperlipidemia following infection was higher in people who already had risk factors for hyperlipidemia,” he says. (According to the U.S. Centers for Disease Control and Prevention, risk factors for high cholesterol include preexisting health conditions, such as Type 2 diabetes and obesity, as well as a history of smoking or poor diet.) “There are potentially two pathways at play,” Al-Aly says. First, the infection could be the sole cause of a person’s new-onset high cholesterol or related health issues. “Or two, the virus could be accelerating existing problems,” he says. In other words, someone who would have developed cholesterol problems in five or 10 years got them earlier because of the infection. “Both of these could be happening,” he adds.
The long-term health implications of any post-COVID metabolic or cholesterol changes are another gap in the data that only time and follow-up research can fill. “At the levels we observed, these changes could lead to heart attacks, stroke, and all the other complications associated with high cholesterol or triglycerides,” Al-Aly says. However, it remains to be seen whether these complications will arise.
Finally, the research to date is based on infections with early forms of the SARS-CoV-2 virus. “Our work was prior to Omicron, and it’s possible that newer variants don’t have the same effects,” Schlagenhauf says. However, she doubts this will be the case. “I think the mechanisms causing the changes are likely similar with all the variants,” she says. Again, only time and follow-up research will provide solid answers.
How to protect yourself
The pandemic may have peaked, but the risk of contracting SARS-CoV-2 is not going away any time soon. While widespread vaccination has helped limit the virus’s severity, and also, to some extent, a person’s risk for Long COVID complications, many people may still be at risk for cholesterol or metabolic issues following infection.
What can you do to safeguard yourself? Despite the lack of robust data, some more of Al-Aly’s research has found that vaccination against SARS-CoV-2 reduces the risk of hyperlipidemia by 20%. There are other reasons to think the vaccines may offer some protection. “We found that the severity of the initial infection really mattered,” he says. While even some people who had asymptomatic COVID-19 went on to develop cholesterol problems, he says that people who were very sick during their initial infection were much more likely to have the types of lingering Long COVID metabolic issues documented in his study. “The risk was more robust in people who needed ICU care or were hospitalized,” he says. Since vaccination helps reduce the risk of both severe COVID-19 disease and long-COVID symptoms, it is reasonable to think—though evidence is lacking—that it may also protect against metabolic or cholesterol complications.
Regardless of vaccination status, Al-Aly says it is prudent for anyone who has been infected—and especially those adults who are already at risk for high cholesterol—to get their blood lipids checked by a health care provider. “I would say that if you’ve been infected, you now have a risk factor for hyperlipidemia, and so our advice is to have yourself checked to identify any disturbances or abnormalities,” he says. “Discovering high cholesterol early and managing it is associated with better outcomes.”
If your provider does identify elevated cholesterol or triglyceride levels, Al-Aly says all the usual treatments and remedies—such as exercise, a healthy diet, and statins or other cholesterol-lowering drugs—are appropriate. “Of course there needs to be a discussion between patient and provider, but all the normal remedies are still applicable,” he notes.
It is an unfortunate certainty that, for years to come, the effects of the pandemic will continue to impact human health in a variety of ways. Metabolic and cholesterol problems may be part of the virus’s legacy. However, experts say that with proper monitoring, people can protect themselves from the most dangerous risks of any virus-related cholesterol or metabolic complications. Plus, follow-up work should help researchers gain a better grasp on Long COVID’s risks and remedies. In the end, the lessons of this pandemic may help protect people from viruses of the future.