Hypertension is far too often ignored. As it is largely symptomless, many people do not even know they have the condition, though it can lead to serious health problems such as heart failure, stroke, aneurysm, and kidney damage.
But last month, the spotlight was shone on the condition, when the United States adopted stricter blood pressure guidelines that led to nearly half of Americans being labelled as having hypertension.
Although Singapore did not follow suit, the change forced people here to be more wary of the condition.
In the US, high blood pressure is now defined as 130/80 mmHg (millimetres of mercury) or greater. This is lower than the previous guideline of 140/90 mmHg.
A lower cut-off level means more people will be alerted to the dangers of the condition, and hopefully be motivated to do something.
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. And a larger proportion of them are younger people under 45.
1. WHAT DO THE READINGS MEAN?
In Singapore, as in Australia or Europe, you are considered to have high blood pressure if your reading is 140/90 mmHg or more.
The top value, the systolic blood pressure, indicates how much pressure the blood is exerting against the artery walls when the heart beats. The lower value, the diastolic blood pressure, indicates how much pressure the blood is exerting against the artery walls while the heart rests between beats.
Studies show there is a doubling of the risk of death from ischemic heart disease and stroke with every 20 mmHg increase in systolic or 10 mmHg rise in diastolic pressure.
Still, doctors say it is important to note these numbers are guidelines. They are there to separate the low-risk group from the high-risk one.
Blood pressure also changes in response to activity, stress and one’s surroundings. For instance, it can shoot up while one is getting it measured at a doctor’s office.
“There is no suggestion that you will have a cardiovascular event immediately if you are above the norm,” said Dr Arthur Tan, a cardiologist at Gleneagles Hospital.
The main advantage of having it measured is to indicate if you are in a higher-risk group, and should take steps to lower the risk, he said.
Indeed, the new US recommendation was made largely in response to the results of a federally-funded study called Sprint, which was published in 2015. It was done to see whether treating blood pressure to a target systolic pressure of less than 120 mm Hg is superior to treating to less than 140 mm Hg, which was the commonly recommended target during the time the Sprint trial was conducted.
The study included data from 9,361 adults aged 50 or older with systolic blood pressure of 130 mm Hg or higher and at least one additional cardiovascular disease risk factor. It showed that a systolic blood pressure of less than 120 led to a 25 per cent reduction in the incidence of heart attack, heart failure and stroke, and a 27 per cent drop in the risk of death.
So, there is a real gain in working to get one’s blood pressure down.
2. WHAT HAS CHANGED?
Patients now recognise that a reading of 130/80 mmHg is considered a disease state in the US, said Professor Tan Huay Cheem, a senior consultant cardiologist and the director of the National University Heart Centre Singapore.
HIGH NORMAL, HIGH CONCERN