Reducing blood pressure in middle age ‘most important for heart disease risk’

By Lilian Anekwe

BMJ Group News

Reducing your blood pressure in middle age lowers your risk of heart diseases for the rest of your life, a study shows. Also, people who have low blood pressure at the age of 55 years have the lowest lifetime risk of heart disease, heart attacks, and strokes.

What do we know already?

High blood pressure increases your chances of having a heart attack or a stroke. It can also lead to kidney disease and heart failure. Taking steps to try and reduce your blood pressure is one of the most important ways to reduce your risk of heart and kidney diseases. Taking drugs to reduce your blood pressure can help, as can making changes to include healthier habits into your lifestyle.

But we don’t know what effect making these changes has at different times in your life and if there is any advantage to making changes to your blood pressure in middle age. We don’t know how this might affect the chances that you will have heart diseases in your lifetime (lifetime risk).

So researchers collected information from seven previous studies of 61,585 men and women with heart diseases. They looked at the changes in their blood pressure measurements taken at least 10 years apart, then recorded how many of them went on to have heart disease, a heart attack, or a stroke over a typical period of 14 years. From this they were able to estimate the lifetime risk of these heart diseases, and the effect of low and high blood pressure on their lifetime risk.

What does the new study say?

The researchers calculated that a lifetime risk of eight percent was a meaningful level of risk of heart disease. They showed that the higher a person’s blood pressure was, the younger they tended to be when they reached that level of additional risk.

Starting at age 55 years, which was taken to be a mid-point for middle age, the lifetime risk of heart disease was 53 percent for men and 40 percent for women. This means that around five in every 10 men and four in every 10 women in the study would get a heart disease in their lifetime, regardless of their blood pressure levels.

But people who were able to lower their blood pressure to a healthy level or who had a healthy blood pressure level and maintained it, had the lowest lifetime risk of heart diseases.

People whose blood pressure was less than 120/80 mm Hg had a lifetime risk of heart disease between 22 and 41 percent.

But in people whose blood pressure had reached 160/100 mm Hg or higher or who had been treated for high blood pressure by the age of 55 years, the lifetime risk of heart diseases was between 42 and 69 percent.