Getting COVID-19 is linked with developing high blood pressure within six months after having the infection, especially in people with a preexisting heart condition, or those who are older than 40, Black, or male, according to new research published on August 21, 2023, in the American Heart Association (AHA) journal Hypertension.
Researchers compared people diagnosed with COVID-19 with those diagnosed with the flu, another respiratory virus, and found that those with COVID-19 were more than twice as likely to develop hypertension.
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“Given the sheer number of people affected by COVID-19 compared with influenza, these statistics are alarming and suggest that many more patients will likely develop high blood pressure in the future, which may present a major public health burden,” said senior study author Tim Q. Duong, PhD, a professor of radiology and the vice chair for radiology research at Albert Einstein College of Medicine and Montefiore Health System in New York City, in an AHA release.
Vivek Bhalla, MD, an associate professor of medicine at Stanford Medicine and a nephrologist at Stanford Health in California, who was not involved in the study, agrees: “This study has potential implications for hypertension care, particularly the burden of care, in the U.S.”
First Study to Investigate the Development of Hypertension in People With COVID-19
While COVID-19 is typically more severe in patients with preexisting high blood pressure, including higher rates of hospitalization and death compared with people with normal blood pressure, it hasn’t been clear whether the SARS-CoV-2 virus may in fact trigger the development of high blood pressure or worsen preexisting hypertension, says Dr. Duong.
For the study, researchers used health data from electronic medical records at the Montefiore Health System in the Bronx, New York, which serves a large, racially and ethnically diverse population.
Researchers compared about 45,000 people with COVID-19 between March 1, 2020, and February 20, 2022, and nearly 14,000 people with influenza without COVID-19 between January 2018 and February 20, 2022. All participants had no history of hypertension, and returned for a follow-up within three to nine months after testing positive for COVID-19 or influenza.
More Than 1 out 5 People Hospitalized With COVID-19 Developed Hypertension
Researchers found that 21 percent of people hospitalized with COVID-19 developed high blood pressure, compared with 16 percent of people hospitalized with the flu.
In the participants who had COVID-19 but weren’t hospitalized, 11 percent developed high blood pressure, compared with just 4 percent who had flu but weren’t hospitalized.
Among the people who got COVID-19, the highest risk for hypertension was in those over 40, men, Black individuals, or people with preexisting conditions, such as chronic obstructive pulmonary disease, coronary artery disease, or chronic kidney disease.
High blood pressure was also more common among people infected with SARS-CoV-2 who were treated with vasopressors (drugs that help raise blood pressure when it’s so low you can’t get enough blood to your organs) and steroids, according to the findings.
Study Only Included People Who Sought Care
The authors allow that there are several limitations to the findings: The only people included in the analysis were those who interacted with the healthcare system during the follow-up period and who might be more likely to have severe COVID-19. It’s also possible that some participants had undiagnosed high blood pressure. Finally, vaccine status, which might affect severity of COVID-19 illness, may not have been included in the healthcare system database if COVID-19 vaccines were administered outside of the system.
Although there are several limitations to the study, the findings are intriguing, says Luke Laffin, MD, a cardiologist and the co-director of the Center for Blood Pressure Disorders at Cleveland Clinic in Ohio. While not involved in this study, Dr. Laffin was the lead author in a study published in December 2021 in Circulation that found blood pressure increased during the COVID-19 pandemic among U.S. adults with or without preexisting hypertension. “The new data suggest that COVID-19 infection may be part of the reason for this increase, along with other factors such as lifestyle changes,” he says.
Why Might COVID Make High Blood Pressure More Likely?
Although the study wasn’t designed to uncover why COVID-19 might increase the risk for hypertension, the authors put forth the theory that the virus could infect heart cells and disrupt blood pressure regulation. They also said that acute kidney injury, a common complication during COVID-19 hospitalization, could also be a factor.
The theories suggested by the authors are among the potential mechanisms for this blood pressure increase, but we don’t really know the cause, says Laffin. “We do know emerging data suggests inflammatory and immune-mediated pathways play a role in the development of hypertension, so these pathways may be implicated,” he says.
“Many of the risk factors for hypertension after COVID-19 infection, such as age, Black race, chronic kidney disease, and vascular disease are shared risk factors for the incidence of hypertension in general, so perhaps the findings in this study reflect an acceleration of disease rather than uncovering a novel mechanism of hypertension per se,” says Dr. Bhalla.
Nearly Half of U.S. Adults Have High Blood Pressure
Blood pressure is simply a measurement of the pressure of blood pushing against the walls of the arteries. If blood pressure stays high (known as hypertension) for a long time, it can cause damage to organs, including your heart, brain, kidneys, and eyes.
Nearly half of U.S. adults (47 percent) have hypertension, which is defined as having a systolic blood pressure greater than 130 millimeters of mercury (mmHg) or a diastolic blood pressure greater than 80 mmHg, or as taking medication for hypertension, according to the Centers for Disease Control and Prevention (CDC).
“Hypertension control rates are already very poor in the United States. If COVID-19 infection is the cause of even higher blood pressure, then we must be even more attune to our patient’s risk factors for hypertension and perform appropriate screening so they can be treated if they do have hypertension,” says Laffin.
Screening for high blood pressure is especially important because the condition usually has no symptoms, per the CDC.