If our blood pressure guidelines lowered the cut-off for hypertension to match the new American standard, it would double the proportion of Aussie adults with the condition
So say Professor Gary Jennings from the University of Sydney and Executive Director of Sydney Health Partners and colleagues, writing in the Medical Journal of Australia.
The authors note that the American guidelines, released by the American College of Cardiology and the American Heart Association, dropped 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% to 45.6% by changing the threshold alone, affecting an additional 31 million people”, Prof Jennings and colleagues wrote.
“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.”
They write that “there are few things more controversial in medicine than when authoritative bodies shift the goalposts for common conditions and redefine normal values”.
“This is particularly the case when the normative values for common chronic disease risk factors in the community, such as blood pressure or cholesterol, are made more stringent. In the stroke of a pen, millions of people have a disease or a risk factor they did not have the day before. Is this ‘the medicalisation of life’ referred to by Illich?
“Is this medicalisation the danger or is the bigger problem that large swathes in the community are not aware that they are at risk of incidents such as heart attack, stroke and sudden cardiac death and need to protect themselves against these future catastrophic events?
“Blood pressure and most other risk factors for chronic disease are made common by the lifestyle of individuals. If redefining the cut-off for a condition such as hypertension increases the prevalence in the community, it could be asked if it is the community that is getting things wrong or if it is the well meaning authorities that review the evidence and present recommendations.”
Such a move would increase the proportion of Australian adults recommended for antihypertensive therapy based on blood pressure readings – both in the general population, but also more so for those with chronic conditions such as chronic kidney disease, heart disease or diabetes.
There would also be a rise in the proportion of adults who would need their antihypertensive therapy intensified due to failure to meet blood pressure targets.
“There are additional considerations if the ACC/AHA guidelines were to be adopted, including the economic impact of an increasing proportion of the population prescribed antihypertensive medication and the potential for non-compliance,” the authors write.
“Medication non-compliance for hypertension has been shown to be significantly associated with younger age groups, many of whom would be eligible for drug therapy under the new guidelines.”
Jennings and colleagues wrote that hypertension had arguably been “a sleeper” in the Australian health scene.
“In a national survey, 71% 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.
Recently a study published in JAMA Internal Medicine argued that adopting the US standards could do more harm than good.
This could be due to more people being labelled as unwell, even if they are at low risk of a disease and increasing the risk of anxiety and depression; negative effects due to blood pressure treatment; and difficulty getting insurance due to hypertension as a “pre-existing” condition.
And Sydney pharmacist and proprietor of Balmain Community Pharmacy and Blooms the Chemist Edgecliff, Caroline Diamantis, told the AJP that due to pharmacists’ accessibility within the community, they are well placed to help raise awareness of the importance of blood pressure control.
The number of people that we identify of being at a high-risk category and have no idea is huge,” she says.
“They’re the people we target and pharmacy is the perfect place. We are the most accessible people, they’re coming in to get a prescription for whatever it is, it might not even be related to blood pressure—and then they start saying, ‘oh gosh I’ve been so unwell, I’ve been short of breath for the last three months and I don’t know what’s wrong with me’. And that’s again leading conversations.
“The most important message is that we are accessible, very well clinically trained, we understand the impact of lifestyle choices and we have the tools in the store a finger touch away.”