A new study shows that lowering blood pressure more with a target of 120 instead of 140 mm Hg systolic can cut deaths by 25 per cent. A third of U.S. and Canadian adults have high blood pressure. So millions could be affected by the new findings. But U.S. government-funded researchers who ran the study say it’s too soon for anyone to change what they are doing just yet.
“This is huge – I mean, 25 per cent less deaths and a third – 33 percent – less heart attacks, strokes and heart failure – that’s huge,” says Dr. Julia Lewis, a kidney specialist at Vanderbilt University who took part in the new study.
Normally, systolic blood pressure should be less than 140 mm Hg (mercury) and diastolic pressure of less than 90 mm Hg. It is written as – systolic over diastolic (for example 120/80 mm Hg). Blood pressure is lowest in the early morning, rises as the day progresses, and then dips down during the night and earliest hours of the morning. Blood pressure can fluctuate under different circumstances.
World Health Organization says that hypertension (high blood pressure) causes seven million premature deaths worldwide each year. Hypertension affects 22 percent of Canadians. It is estimated that 25 percent of the 42 million people with high blood pressure in the United States are unaware that they have hypertension. These patients probably have no symptoms. That is dangerous. That is why it is called a silent killer.
The incidence of hypertension increases with age. Most elderly Canadians have high blood pressure – probably due to thickening of blood vessels. No cause is identified in 80 to 95 percent of people with hypertension. This is known as idiopathic or essential hypertension. Others have hypertension due to primary disease of kidneys or due to certain hormonal disorders.
Blood pressure also varies from minute to minute, depending on levels of stress and physical activity. “White-coat hypertension” means a person’s blood pressure is up in the doctor’s office but not elsewhere.
Hypertension can be prevented and treated with lifestyle changes – with or without medication. Eat a healthy diet, lose weight if you are overweight, do not smoke, limit alcohol intake, eat a low salt diet, minimize sugar intake, do regular exercise, relax and learn to manage stress with laughter and meditation.
If your doctor wants you to take pills to control your blood pressure then make sure you take it regularly. Research has shown that 50 per cent of the patients with high blood pressure discontinue their antihypertensive medications by the first year. This is not good.
The U.S.-funded study is not quite finished but the effects on the heart were strong and clear. Getting blood pressure to 120 or lower reduced rates of cardiovascular events, such as heart attack, stroke and heart failure by a third. It reduced the deaths from any cause by 25 percent.
The research team is still studying the effects of lower blood pressure on dementia, memory loss and kidney function. Other studies have suggested lower blood pressure can help reduce or delay dementia symptoms and boost kidney function.
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