A new report has found that a significant number of Australians could be living with undiagnosed, untreated or uncontrolled high blood pressure
The report, from the Baker Heart and Diabetes Institute and published in the Journal of Hypertension, compared standard “office” measures of blood pressure with 24-hour measures of blood pressure in city and regional areas across the country.
The authors say that increasingly, ambulatory blood pressure monitoring is being recognised as a “superior prognostic method” for determining the risk of cardiovascular events and that the traditional clinic measurement model has some limitations.
“Specifically, misdiagnosis occurs in a considerable proportion of patients,” they write. “The main issue is white-coat hypertension characterised as measurement above hypertension thresholds in the presence of the physician.
“Another common issue is masked hypertension in which patients are deemed normotensive but exceed hypertension thresholds at other times during their normal daily life. Importantly, ABPM provides measures of blood pressure during sleep at night, which is an important prognostic measure for long-term cardiovascular risk.”
The analysis was a sub-study of the AusDiab3 project, the national, population-based survey initiated in 1999-2000 to measure the level of diabetes and cardiovascular risk factors in the population. In this research, 508 participants, 47% of whom were men, were analysed.
“The mean field office SBP/DBP was 127/73mmHg and mean 24-h BP was 121/73mmHg,” the authors wrote. “The day time SBP from ABPM was 126mmHg which is similar to the field office value but the day DBP was 3.5mmHg lower than the field office DBP.
“Over the 24-hour period, the ABPM recordings followed the usual pattern of nocturnal dipping in SBP and DBP with a smooth transition taking several hours to reach the daytime peak from the night time nadir.”
The study found masked hypertension in about one in five participants.
Nearly half of the study group had high blood pressure, but only a quarter were taking medication to treat it.
Among those were taking such medication, men were three times more likely than women to still have blood pressure readings that were too high.
Head of Neuropharmacology at the Baker Institute, Professor Geoff Head, said the findings highlighted the importance of “out of office” blood pressure assessments and considerable gaps in effectively diagnosing and treating high blood pressure.
“Although the common assessment of hypertension has been via clinic measurements, this technique has limitations,” said Professor Head.
Professor Head described the findings as staggering and is calling for additional measures to diagnose and treat blood pressure.
“High blood pressure is a major risk factor for heart attack and stroke. These results clearly suggest we need to make changes in screening and treatment plans as soon as possible,” he said.
Prof Head is calling for a 24 hour blood pressure test to be made available under Medicare. He said patients that could not afford the more effective method of diagnoses were missing out on potentially life-saving treatment.
“The answer is two-fold. First we have to encourage GPs to diagnose high blood pressure using the most appropriate methods and the second is to make screening cheaper for those who cannot afford it,” he said.
“High blood pressure in Australia is a growing issue and unfortunately one that is linked to many deadly conditions.”
Meanwhile a study involving scientists from The University of Western Australia and the Royal Perth Hospital Medical Research Foundation has revealed 50 per cent of Australians living with high blood pressure do not realise they have the condition.
The research is part of a global study published in the European Heart Journal Supplements for May Measurement Month, a health campaign centred around Hypertension Day (Friday 17 May) to create awareness of high blood pressure.
The research found of 3817 people involved in the Australian component of the study, 31.2 per cent had high blood pressure and only half of them were aware of it. Of those who received treatment, 40 per cent still had blood pressure above the recommended level.
Australian study lead UWA Professor Markus Schlaich, who holds the Dobney Chair in Clinical Research at the Royal Perth Hospital Medical Research Foundation said the results were alarming.
“Even though effective treatments for this condition are widely available, only half of the people affected by it are being treated, and of those treated only 60 per cent are having their blood pressure adequately controlled,” Professor Schlaich said.
“This tells us that the majority of people who have high blood pressure may have never had it measured and are unaware of their condition.”