Antihypertensive therapy does not increase the chance of becoming ill with COVID-19, finds a new study funded by the Biomedical Research Centre (BRC) at Guy’s and St Thomas’ NHS Foundation Trust.

The population-based study used the CPRD GOLD database of anonymised electronic health records, representative of patients from general practices across the country. Analysis of nearly 17,000 COVID-19 cases and over 70,000 matched controls found no evidence that antihypertensive therapy was associated with increased risk of COVID-19 diagnosis or mortality.

Most classes of antihypertensive therapy showed negative associations with COVID-19 diagnosis. This suggests there could be a protective effect of some classes of antihypertensive therapy against COVID-19, although further evidence is needed for conclusive results.

Antihypertensive drugs have been implicated in COVID-19 through upregulation of the angiotensin-converting enzyme 2, which is the receptor through which the virus enters the body.

Studies have so far produced conflicting results, with methodological and sampling issues leading to estimated associations being susceptible to bias.

Associations were sensitive to adjustment for confounding and healthcare-seeking behaviours, but there was no evidence that antihypertensive therapy is associated with increased risk of COVID-19 diagnosis or mortality.

Lead author, Dr Emma Rezel-Potts, Research Associate from King’s College London said: “Antihypertensive drugs represent the most frequently prescribed medicines in the UK, used by 15% of adults with long-term conditions. These pre-existing conditions are prevalent among those receiving healthcare for COVID-19 and have also been associated with high COVID-19 case fatality rates, raising concerns about possible associations with antihypertensive treatment (AHT).

“Our studies indicate there is no causal relationship between AHT and susceptibility to COVID-19. This study adds to the evidence that antihypertensive therapy may be safely continued during the COVID-19 pandemic.

“Most classes of antihypertensive drugs actually showed a negative relationship with COVID-19 diagnosis, suggesting a potentially protective effect. This is a promising finding but one that is not conclusive and requires more research.

“Early on in the pandemic, testing was not widespread so studies exploring the relationship between AHT and COVID-19 were restricted to only the most severe cases. We accounted for healthcare-seeking behaviours in our modelling which was important to reduce bias in our findings.”

The full study can be found on the British Journal of Clinical Pharmacology website.