Experts say tighter standards would show just how much hypertension there is in the Australian population.

If the standards of the recently revised American guidelines for the diagnosis and management of hypertension were adopted here, the proportion of Australian adults classified as having high blood pressure would double, according to the authors of a new article in the Medical Journal of Australia.

The American guidelines, released by the American College of Cardiology (ACC) and the American Heart Association (AHA), drop the definition of hypertension in the general population from 140/90 mmHg down to 130/80 mmHg.

As a result, the “crude prevalence of hypertension in the US among adults increased from 31.9 per cent to 45.6 per cent by changing the threshold alone, affecting an additional 31 million people”, the paper states.

Adopting the ACC/AHA guidelines throughout Australia would double the proportion of adults classified as having hypertension,” they wrote.

“That is, of the 18 million individuals aged 20 years and over, the health status of 4.5 million would change.

“It would also increase the proportion of adults recommended for antihypertensive therapy based on blood pressure readings in the general population, and even more so in populations with chronic diseases (individuals who reported having diabetes, heart disease or chronic kidney disease).

“There would be an increase in the proportion of adults who would require intensification of their antihypertensive therapy due to failure to meet blood pressure targets.”

Professor Garry Jennings from the University of Sydney and colleagues say hypertension is “a sleeper” in the Australian health scene.

“In a national survey, 71 per cent of the population with blood pressure levels 140/90 mmHg, our present threshold, were not aware they had hypertension,” they wrote.

“We recently found that community awareness of high blood pressure as a forerunner of heart disease and stroke is very low in Australia. Without better community awareness and engagement, we are unlikely to make progress.

“If the ACC/AHA guidelines do nothing more than provoke a debate on how we can use new evidence to devise better strategies, we should be grateful.”

Jennings and colleagues concluded that at this time, “we do not feel it is the time to make such change to the Australian guidelines”, preferring to monitor the effects of the new guidelines in the US, ongoing trials and further analysis.