New York, Aug 21 : Covid-19, caused by SARS-CoV-2 virus, is significantly associated with the development of high blood pressure in adults with pre-existing heart conditions, finds new study based on analysis of electronic medical records of more than 45,000 people. 'While Covid-19 is typically more severe in patients with preexisting high blood pressure, including higher rates of hospitalisation and mortality compared to people with normal blood pressure, it is unknown whether the SARS-CoV-2 virus may trigger the development of high blood pressure or worsen pre-existing hypertension,' said Tim Q. Duong, Professor of radiology at Albert Einstein College of Medicine and Montefiore Health System in New York City. The retrospective observational study, published in the journal Hypertension, is the first to investigate the development and risk factors associated with persistent high blood pressure in people with Covid infection compared to influenza, a similar respiratory virus. Hypertension is classified as having top and bottom numbers greater than or equal to 130/80 mm Hg. The study included 45,398 people with Covid-19 -- hospitalised between March 1, 2020 and February 20, 2022 -- and 13,864 people with influenza without Covid -- hospitalised between January 2018 and February 20, 2022 -- who returned to the hospital system for any medical reasons within an average follow-up period of six months. The analysis found 21 per cent of people hospitalised with Covid and 11 per cent of those who were not hospitalised for Covid developed high blood pressure, compared to 16 per cent of people hospitalised with influenza and 4 per cent of those not hospitalised for influenza. People hospitalised for Covid were more than twice as likely and those not hospitalised are 1.5 times more likely to develop persistent hypertension compared to people hospitalised and non-hospitalised with influenza, respectively. People infected with SARS-CoV-2 who were over 40 years old, or those with preexisting conditions, such as chronic obstructive pulmonary disease, coronary artery disease or chronic kidney disease, had an elevated risk of developing high blood pressure. Persistent high blood pressure was more common among people infected with SARS-CoV-2 who were treated with vasopressor and corticosteroid medications during the pandemic. 'Given the sheer number of people affected by Covid-19 compared to 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,' Duong said. 'These findings should heighten awareness to screen at-risk patients for hypertension after Covid-19 illness to enable earlier identification and treatment for hypertension-related complications, such as cardiovascular and kidney disease.' Isolation, psychosocial stress, reduced physical activity, unhealthy diet and weight gain during the Covid pandemic may have contributed to the development of high BP among the participants, the researchers said. /IANS