Having high blood pressure may more than double the risk of severe Covid-19 in people who become infected with the virus, even in those who are fully vaccinated, according to a research letter in Hypertension, published online in July.
Using the medical records of 912 Covid patients who had received at least three doses of an mRNA vaccine (Pfizer or Moderna) before becoming infected with the Omicron variant during the winter 2022 surge, the investigators correlated the severity of their illnesses with medical variables that have been associated with poorer Covid outcomes, including hypertension, diabetes, heart disease, chronic kidney disease, chronic obstructive pulmonary disease, asthma, and obesity, as well as longer time since last vaccination dose. The patients, 145 (16 percent) of whom were hospitalized, were all in the medical system at Cedars-Sinai Medical Center in Los Angeles.
In this analysis, older age, kidney disease, prior heart attack, heart failure, and time from last vaccine to infection were associated with significantly increased risk of hospitalization for Covid—but the greatest risk factor was hypertension, even after the presence of other chronic conditions was accounted for. Although the mechanism behind the relationship is still unclear, the investigators speculated that delayed clearance of the virus and a prolonged inflammatory response in people with hypertension may be contributing factors.
Considering that nearly half of all U.S. adults have hypertension (defined as a systolic blood pressure of more than 130 or a diastolic blood pressure greater than 80), the findings are important and suggest that it is not just older people with underlying medical conditions who are at most risk for developing severe Covid. According to the lead author, Joseph E. Ebinger, M.D., “Breakthrough Omicron infection severe enough to cause hospitalization can happen to an adult of any age, especially if a person has high blood pressure, even if they have no other major chronic disease. The people who are most at risk are not necessarily who we think they are. They are not the sickest of the sick, and this was a surprising finding.”
Some caveats: The study did not look at whether hypertension was under control in the participants, so it’s not known whether reducing high blood pressure would stave off severe Covid in infected individuals. Also, the study was done before the current Omicron variants began circulating, and it was conducted at a single medical center. More studies are needed to see if the findings apply to the latest dominant strains of the Covid virus and to a wider population—but before such research is in, it remains prudent to keep your blood pressure down to avoid a range of health problems.
