Under-50s with IDH have increased risk of heart attack, study finds

Study shows lifestyle changes key for those with particular blood pressure condition

Known as isolated diastolic hypertension (IDH), the American Heart Association defines it as a diastolic blood pressure greater than 80mmHg and systolic blood pressure less than 130 mmHg

People under 50 with a particular form of high blood pressure affecting up to 11 per cent of the adult population are more at risk of a heart attack or death, a global study led by NUI Galway has found.

The researchers found over-50s with high diastolic blood pressure and normal systolic blood pressure – a high value on the bottom blood pressure reading – are not at increased risk of cardiovascular disease, yet the condition increases risk of cardiovascular events among younger people.

Known as isolated diastolic hypertension (IDH), it is defined by the American Heart Association as a diastolic blood pressure greater than 80mmHg and systolic blood pressure less than 130 mmHg.

The research was led by Prof William McEvoy, consultant cardiologist at Galway University Hospitals and medical director of the National Institute for Prevention and Cardiovascular Health.


The findings published in the US journal Hypertension examined data from 11,135 patients. All underwent a 24-hour blood pressure assessment, considered more accurate than office-based blood pressure measurement when managing cardiovascular risk. The study does not give a breakdown on under-50s with the condition but previous US research showed one in eight 20-55 year olds had IDH, which is likely to be replicated in Ireland.

“While IDH is less common than other forms of blood pressure, it can be seen in 6-11 per cent of the adult population and is more common in younger adults. What we found is that only patients with IDH who are younger than 50 are at greater risk of heart attack or cardiovascular events,” Prof McEvoy said.

Previous research left unanswered questions, he said. Patients under 50 with IDH need to tackle unhealthy lifestyle and diet issues. “They also need more close monitoring of their systolic blood pressure – the top value on the blood pressure reading – as they are more likely to develop high systolic blood pressure values that may require drug treatment.”

Their findings do not necessarily mean young adults with IDH be treated with blood pressure lowering medications. “While they are at increased risk of cardiovascular events, the actual likelihood of an event is still low in young people,” he added.

They should make healthy changes to lifestyle and defer drug treatment, while ensuring they have annual blood pressure checks, unless elevated systolic blood pressure develops.

Kevin O'Sullivan

Kevin O'Sullivan

Kevin O'Sullivan is Environment and Science Editor and former editor of The Irish Times