Late last year, a number of unexplained pneumonia cases surfaced in Wuhan, China. Later scientists revealed that it is caused by a familiar group of pathogens, coronavirus. The WHO later named this virus, COVID-19. The virus is highly contagious, infecting millions in the last couple of months.
From previous studies, it is considered that angiotensin-converting enzyme (ACE2) is the receptor for the COVID-19 virus to enter the host cell. ACE2 is a widely expressed receptor in several organ systems of the human body, including cardiovascular and respiratory systems. The enzyme helps in catalyzing angiotensin II to angiotensin 1-7, which is the peptide counteracting proinflammation caused by Angiotensin II.
Studies have proven that hypertension is a common condition that co-occurs in patients with COVID-19. A previously conducted study, involving 1099 COVID-19 patients reported that 23.4% of the population also suffered from hypertension. Due to the coexisting status of hypertension and COVID-19 and the involvement of ACE2 in hypertension, the authors of this study speculate that hypertension may directly be involved with the pathogenesis of COVID-19.
To confirm if hypertension affects the progress and prognosis of COVID-19, the published study was conducted. The study involved 310 patients from the Central Hospital of Wuhan and Wuhan Jinyintan Hospital. All the participants according to the WHO were tested positive for COVID-19. The study was later divided according to high blood pressure (hypertensive and non-hypertensive group). To avoid unwanted complications, the hypertension group was further segregated to exclude patients with other complications other than hypertension.
All the participants were monitored closely and the entire course of the disease was recorded. The median age of the participants in the study was 62 years and the prevalence rate of hypertension was 36.5%. The authors speculate that the high prevalence rate of hypertension in the study group could be due to the high median age. The study also revealed that COVID-19 patients with high blood pressure showed higher mortality.
Evidence suggests that an imbalance of cytokines could be a possible correlation between COVID-19 and hypertension. An increase in cytokines like IL-6, IL-7, and tumor necrosis factor is associated with the development of hypertension. It should also be noted that the increased levels of cytokines, may potentially activate excessive inflammatory reactions, resulting in cell and lung damage.
Overall the comparative study conducted using COVID-19 patients with and without hypertension showed that patients who were hypertensive were more likely to be severely affected with COVID-19 compared to the non-hypertensive group. It must be brought to light that there might be a small number of people with hypertension not recorded because the diagnosis of hypertension in this study was extracted from medical history data.
Finally, the authors conclude that much larger groups need to be studied since the current result could be due to the higher aged participants. In the future, additional complications also need to be analyzed like ARDS, renal injury focusing on its risks associated with hypertension and COVID-19.