Thursday, 16 November 2017

New 130/80 high blood pressure guideline by American Heart Association means more people in Singapore - 1 in 3 - have hypertension

New US standard redefines high blood pressure
Stricter limit of 130/80 means action should be taken sooner, including adoption of lifestyle changes: Report
The Straits Times, 15 Nov 2017

LOS ANGELES • High blood pressure was redefined on Monday by the American Heart Association (AHA), which said the disease should be treated sooner, when it reaches 130/80mm Hg, and not the previous limit of 140/90.

Doctors now recognise that complications "can occur at those lower numbers", said the first update to comprehensive US guidelines on blood pressure detection and treatment since 2003.

A diagnosis of the new high blood pressure does not necessarily mean a person needs to take medication, but that "it's a yellow light that you need to be lowering your blood pressure, mainly with non-drug approaches", said Dr Paul Whelton, lead author of the guidelines published in the AHA journal, Hypertension, and the Journal of the American College of Cardiology.

Healthy lifestyle changes include losing weight, exercising more, eating healthier, not smoking, avoiding alcohol and salt, and reducing stress.

The new standard means nearly half (46 per cent) of the US population will be defined as having high blood pressure. Previously, one in three (32 per cent) had the condition, which is the second leading cause of preventable heart disease and stroke, after cigarette smoking.

The normal limit for blood pressure is considered 120 for systolic, or how much pressure the blood places on the artery walls when the heart beats, and 80 for diastolic, which is measured between beats.

Once a person reaches 130/80, "you've already doubled your risk of cardiovascular complications compared to those with a normal level of blood pressure", said Dr Whelton.

"We want to be straight with people - if you already have a doubling of risk, you need to know about it."

The new guidelines are expected to lead to a surge of people in their 40s with high blood pressure - once considered a disorder mainly among people aged 50 and older.

"The prevalence of high blood pressure is expected to triple among men under age 45, and double among women under 45," according to the report.

Damage to blood vessels is already beginning once blood pressure reaches 130/80, said the guidelines, which were based in part on a major US government-funded study of over 9,000 people nationwide.

The category of prehypertension, referring to those with systolic pressure of 120-139, no longer exists. The report said: "People with those readings now will be categorised as having either elevated (120-129 and less than 80) or stage 1 hypertension (130-139 or 80-89)."

Medication is recommended for people with stage 1 hypertension only "if a patient has already had a cardiovascular event such as a heart attack or stroke, or is at high risk of heart attack or stroke based on age, the presence of diabetes mellitus, chronic kidney disease or calculation of atherosclerotic risk".

The proper technique must be used to measure blood pressure, and levels "should be based on an average of two to three readings on at least two different occasions", according to the new guidelines.

Dr Satjit Bhusri, a cardiologist at Lenox Hill Hospital in New York, said he agrees with the change "because it allows for early lifestyle changes to be addressed".

He added: "It is important, however, to realise that the change in the definition does not give course to increased prescriptions of medications. Rather, it brings to light the need to make lifestyle changes."


More hypertensives here if Singapore adopts new rate
By Salma Khalik, Senior Health Correspondent, The Straits Times, 15 Nov 2017

Overnight, Singapore will have one in three people suffering from high blood pressure instead of one in four - if it adopts a new cut-off rate recommended by the American Heart Association (AHA).

But the vast majority of these newly diagnosed hypertensives, classified as "high blood pressure stage 1", will need to make only lifestyle changes to reduce their risk of getting heart attacks and stroke.

The stricter rate recommended by the AHA is 130/80 versus the existing 140/90.

It is based on solid evidence, said Professor Tan Huay Cheem, director of the National University Heart Centre, "so there's no reason to reject these recommendations".

But he added: "We should still treat patients with stage 1 hypertension with lifestyle changes and start drug treatment only if he has multiple other risk factors (for example, diabetes mellitus, etc)".

Prof Tan also said the 130/80 cut-off is for at least two readings done at home. The cut-off at clinics stays at 140/90 as anxiety tends to raise a person's blood pressure, he said.

Dr Chee Tek Siong, a cardiologist in private practice and a board member of the Singapore Heart Foundation, shares Prof Tan's view and said treatment would be given to high-risk cases, who have issues like diabetes, high cholesterol, obstructive sleep apnea and kidney failure.

The AHA estimates that only one in five of the stage 1 hypertensives might need medication to reduce blood pressure. The rest should be given advice to make lifestyle changes and have their blood pressure checked after three to six months, he added.

Lifestyle changes include reducing salt in one's diet and eating more potassium-rich foods like bananas, potatoes, avocado and dark leafy vegetables, exercising more, drinking less alcohol and not smoking.

Dr Paul Chiam, a cardiologist at Mount Elizabeth Novena Hospital, highlighted the need for people to know the importance of strict blood pressure control "as we know that better BP (blood pressure) control does lead to fewer strokes, heart and kidney disease".

Dr Daniel Yeo, a cardiologist at Gleneagles Hospital, noted that Canada and Australia adopted the stricter cut-off last year, so the AHA's move was no surprise.

* Singapore to keep 140/90 threshold for hypertension
Singapore won't take up new US cut-off for hypertension
MOH will keep to value used in Europe, Australia; adopting new US limit may affect insurance coverage, say doctors
By Salma Khalik, Senior Health Correspondent, The Straits Times, 18 Nov 2017

Singapore will not be adopting the new, stricter high blood pressure definition of 130/80 that the American Heart Association (AHA) has recommended.

It will continue to use the current 140/90 to indicate hypertension. This is the value also used in Europe and Australia, a Ministry of Health (MOH) spokesman said.

She added: "Essentially, while these new guidelines change the definition of hypertension for US patients, they do not change the approach to management in a major way."

This is because despite the new cut-off, about 80 per cent of the newly defined hypertensives in the United States will not require any medication, only lifestyle changes.

Based on the new definition, 46 per cent of Americans are now considered to be suffering from high blood pressure, up from 36 per cent.

The spokesman said MOH will continue to review the evidence of the new AHA guidelines and how they apply to the local population.

She added: "Blood pressure can be kept in the healthy range by living a healthy lifestyle such as having a balanced diet, avoiding excess salt intake, having regular physical activity and not smoking."

Dr Chin Chee Tang, a senior cardiologist at the National Heart Centre Singapore, said doctors have always known that the effects of blood pressure on health are a continuum, so thresholds for "normal" or "not normal" are not always useful.

Dr Chin said: "The lower the blood pressure is, the lower the risk of adverse outcomes. This has to be tempered with the increased risk of potential side-effects of treatment."

He said the main advantage of the new US cut-off is it could "increase awareness of the dangers associated with high blood pressure, and hence an earlier drive for individuals to optimise their blood pressure".

But the downside of a lower threshold includes implications for insurance coverage. It would also affect future research and treatments by making comparisons more difficult, he said.

Dr Chia Shi Lu, head of the Government Parliamentary Committee for Health, said "there is no reason for us or other countries to adopt that standard as yet" because it is very much like the debate over the cut-off point for diabetes or cholesterol levels.

These are all continuums, and a person does not suddenly tip over from being healthy to unhealthy at a particular point.

Dr Chia said: "If we change, suddenly, we will have many more people classified as hypertensive, and this may result in unnecessary treatment for many."

Like Dr Chin, he said it might also affect health insurance coverage, such as an increase in premiums to cover the additional risk, "which may in fact be very little".

The ministry has taken the right approach, said Dr Chia, an orthopaedic surgeon at Singapore General Hospital. He added: "There is no solid basis for saying now that a systolic pressure of 130 is significantly riskier."

The 2010 National Health Survey found that 23.5 per cent of people in Singapore are hypertensive, with one in four not being aware of it.

More than half the people aged 60 years and older have high blood pressure.

According to the World Health Organisation, raised blood pressure is responsible for 7.5 million deaths a year, or almost 13 per cent of all deaths.

It is a major risk factor for heart diseases and stroke. People who are obese or diabetic are more likely to have hypertension.

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