A new study involving a team from Galway, has questioned an element of recent lower, blood pressure thresholds, recommended in revised 2017 American medical guidelines, which are also in use here.

The US guidelines changed the definition of hypertension from a blood pressure of 140/90 or more, to a blood pressure of 130/80 or more.

The Irish team along with other researchers found that the 130/80 specific blood pressure pattern did not appear to adversely affect a patients' health.

As a result they concluded that patients with a bottom blood pressure number of over 80, but a normal top blood pressure number below 130 are potentially at risk of being over treated.

Blood pressure levels are denoted by two numbers, one above the other.

The top number is the systolic pressure, when a heart beats to pump blood out.

The bottom one is the diastolic pressure, when the heart is resting between beats.

The Irish team worked with US investigators and their research is published today in the Journal of the American Medical Association.

They specifically looked at the new guidelines for the bottom blood pressure number, which was reduced from 90 to 80.

The team has warned that it could mean up to 150,000 blood pressure patients here potentially receiving treatment with no additional benefit.

Professor Bill McEvoy, Medical & Research Director of the National Institute for Prevention and Cardiovascular Health, said that although there are differences between American and European guidelines, in how blood pressure is defined, in general both sets of guidelines recommend a target blood pressure of 130/80 be achieved, for those who are receiving treatment to lower their blood pressure.

He said that the study findings could have implications for Irish adults, as clinicians could now be aiming to get the lower number (diastolic) to less than 80, despite the patient having a normal top (systolic) blood pressure of below 130.

The US recommendation to lower the threshold was based on expert opinion, not on clinical trials.

The Irish team is from the National Institute for Prevention and Cardiovascular Health and the National University of Ireland Galway.