High blood pressure, or hypertension, affects many people globally and contributes to serious health issues like heart disease, stroke, and kidney disease. While lifestyle and genetics are known contributors, research is exploring the potential role of viral infections. This field investigates how viruses might influence blood pressure regulation and contribute to chronic hypertension.
Understanding the Link Between Viruses and Hypertension
Research indicates that viruses can play a part in developing or worsening high blood pressure in some individuals. This connection is a recent focus for scientists, distinct from temporary blood pressure increases during acute illness. The understanding points towards long-term effects of viral infections on the cardiovascular system, contributing to persistent hypertension.
Mechanisms of Viral Impact on Blood Pressure
Viruses may influence blood pressure through several biological pathways. One significant mechanism involves inflammation. Viral infections can trigger a sustained inflammatory response that damages blood vessel walls, causing them to narrow or become less flexible, which in turn elevates blood pressure. This process can involve immune cells releasing signaling molecules called cytokines, such as tumor necrosis factor-alpha (TNF-alpha), which then stimulate the release of endothelin-1, a peptide that constricts blood vessels.
Another pathway is endothelial dysfunction, where viruses directly damage the inner lining of blood vessels, known as the endothelium. This injury can lead to impaired blood vessel function, affecting their ability to regulate blood flow and increasing vascular resistance. Some viruses also interfere with the renin-angiotensin system (RAS), a complex hormonal system central to blood pressure regulation. For example, SARS-CoV-2, the virus causing COVID-19, enters cells via the ACE2 protein, an enzyme involved in dampening the effects of angiotensin II, a powerful vasoconstrictor.
The body’s immune response to a viral infection can also affect vascular health. Chronic immune activation, characterized by increased levels of certain immune markers, has been linked to chronic hypertension. Additionally, certain viruses can impair kidney function, leading to fluid retention and elevated blood pressure. For instance, viral-induced endothelial dysfunction in the kidneys can result in vasoconstriction and increased vascular permeability, altering blood flow and resistance within the kidneys.
Specific Viruses and Their Clinical Relevance
Several specific viruses are being investigated for their links to hypertension.
Cytomegalovirus (CMV), a common herpesvirus affecting many adults, has been associated with increased arterial stiffness and elevated blood pressure. Studies suggest that CMV infection can independently cause an increase in blood pressure and contribute to artery hardening. CMV may do this by stimulating renin expression, an enzyme in the renin-angiotensin system that raises blood pressure.
The Epstein-Barr Virus (EBV), another widespread herpesvirus, is also suspected of affecting blood pressure regulation. Research indicates that hypertension is associated with an increased risk of EBV reactivation. While the precise mechanisms are still being explored, chronic inflammation from persistent viral infections may promote disease progression, including cardiovascular effects.
SARS-CoV-2, the virus responsible for COVID-19, has shown a significant association with new-onset or exacerbated hypertension. An analysis of over 45,000 people with SARS-CoV-2 infection found a notable link between the virus and persistent high blood pressure, even in those with no prior history. This risk was higher in hospitalized and non-hospitalized cases compared to influenza. The virus’s impact on the cardiovascular system is considered a contributing factor.
This understanding of viruses influencing blood pressure has clinical relevance for diagnosis and treatment. Given the potential for new-onset hypertension after infections like COVID-19, monitoring blood pressure after certain viral illnesses may become important, especially for at-risk individuals (over 40, men, Black adults, or those with existing conditions). This knowledge can help healthcare providers identify and manage hypertension earlier, influencing diagnostic and treatment strategies for patients recovering from specific viral infections.