High blood pressure still biggest risk factor for death in Australia

An analysis of nearly 30,000 deaths has shown high blood pressure is the biggest mortality contributor in Australia.

New research led by UNSW Sydney and The George Institute for Global Health (TGI) confirms that high blood pressure (hypertension) persists as the leading risk factor for death in Australia, reinforcing the need for a concerted national effort to shift the dial on blood pressure control.

Published today in PLOS ONE, the new study confirmed that in the 30 years between 1990 and 2019, raised systolic blood pressure (SBP) remained the leading risk factor for deaths with an identified cause, followed by dietary risks and tobacco use.

In Australia, 34 per cent of adults have high blood pressure – and it is estimated that a 25 per cent reduction could save approximately 37,000 lives annually.

Only 32 per cent of Australians with hypertension have reduced their blood pressures to within the healthy range, compared to 68 per cent of people in Canada, and around half of Australians with high blood pressure are not even aware they have it.

“Effective population-level blood pressure control is an urgent national health priority. Australia lags well behind other high-income countries in blood pressure control and this study shows it is past time for us to act,” said lead author, Alta Schutte, Professor of Cardiovascular Medicine from UNSW and TGI.

“Prevention, detection, and effective treatment are our best weapons against heart disease and stroke. We have these weapons, and we should be using them.”

Losing ground – but we don’t know why

The researchers analysed three decades of Australian data from 1990 to 2019 in the Global Burden of Disease Study to determine the leading risk factors related to deaths overall and to cardiovascular deaths specifically in that time.

According to the analysis, raised SBP contributed to 24 per cent of deaths (29,056 people) from all causes in Australia in 1990, dropping to 14 per cent (21,845) in 2010 and remaining static at 14 per cent (25,498) in 2019. In a similar pattern, raised SBP contributed to 54 per cent, 44 per cent and 44 per cent of cardiovascular-related deaths in 1990, 2010 and 2019 respectively.

Beyond the well-known links with serious cardiovascular conditions, high blood pressure is also implicated in cognitive decline and poorer outcomes in COVID, as well as kidney disease and pregnancy complications.

With the data showing an initial improvement but no subsequent reduction during the past decade, there is a need for renewed attention and investment.

“We know from the existing body of evidence that the initial effect was likely due to the arrival of new medications,” Prof. Schutte continued. “It is hard to pinpoint exactly why we are losing ground, but we do know that refocusing on ensuring effective detection and treatment in primary care would move the dial.

“We also know that there are better approaches to treatment now. Single pill combination therapies that combine two or three low-dose blood pressure lowering medications in one are not only more effective in lowering blood pressure, but also easier for people to take consistently, and cheaper.”

Age and gender differences were also discovered in the study. The contribution of raised blood pressure to stroke-related deaths in men aged 25-49 years was higher than other age groups, exceeding 60 per cent and increasing steeply over time between 1990 and 2019, raising concerns that this group may be falling through the cracks.

“As the evidence shows, elevated blood pressure can occur at any age, so it is an important thing to screen for in people of any age or sex,” commented Professor Garry Jennings, Chief Medical Advisor at the National Heart Foundation, also an author on the paper.

“In particular, men younger than 50 would be advised to have their blood pressure checked at their next GP appointment,” he said.

National taskforce

Prof. Schutte and Prof. Jennings, along with Professor Markus Schlaich, chair of Hypertension Australia, are authors on the paper and founding members of the National Hypertension Taskforce, which was established in 2022 and officially launched by the Australian government in December that year.

The taskforce, a partnership between the Australian Cardiovascular Alliance and Hypertension Australia, aims to improve Australia’s blood pressure control rates from 32 per cent to 70 per cent by 2030 and will release its first roadmap towards this goal on 18 March 2024 at Parliament House, Canberra.