A heart rate above 75 per minute at rest, around age 50, is linked to an increased risk of heart disease over the next 11 years. It would also double the risk of premature death in men.
Resting heart rate – the number of heartbeats per minute without significant physical activity – generally changes with age. A normal resting heart rate is between 50 and 100 beats per minute (bpm). The researchers wanted to know what impact an above normal resting heart rate could have on long-term health, but also if it influenced the risk of premature death (before the age of 75). The results were published in the journal open-heart.
A 21-year study
They show that an increased rate in men in their 50s is associated with an increased risk of heart disease over the next 11 years. To reach this conclusion, the researchers studied a group of men aged 50 and over randomly selected from the general population, all born in 1943 in Gothenburg, Sweden. In 1993, out of a total of 1,450 people who completed a lifestyle questionnaire, 798 had a family history of cardiovascular disease and high stress levels. They also had a full medical examination including their resting heart rate. This allowed them to be divided into four categories: 55 bpm or less; 56-65bpm; 66-75bpm; and more than 75 bpm.
Resting heart rate was measured again in 2003 and 2014, (654 and 536 people respectively) to track any changes in heart rate, treatment, death or death from heart disease or stroke, up to 2014. During the 21-year surveillance period, 119 of 798 men died before their 71st birthday, 237 (almost 28%) developed cardiovascular disease, and 113 (just over 14%) developed coronary heart disease.
Twice the risk of death in those over 75 btm
According to the study’s findings, men with a resting heart rate above 55 bpm in 1993 were more likely to smoke, be less physically active and be more stressed than those with a lower rate. They were also more likely to have other risk factors for cardiovascular disease, such as higher blood pressure and weight.
In those with a resting heart rate above 75 beats per minute in 1993, researchers found about twice the risk of death from any cause, cardiovascular disease and coronary heart disease, compared to those with a resting heart rate of 55 or less.
On the contrary, in those with a stable heart rate between 1993 and 2003, the risk of cardiovascular disease was reduced by 44% over the next 11 years compared to a resting heart rate which had increased during this period. The researchers point out that this is an observational study which, as such, does not establish the cause.
The research was limited to men and the age of the participants may have been an influential factor, the researchers point out. Nevertheless, it shows that it can be important to monitor changes in resting heart rate over time, to anticipate a risk of future cardiovascular disease.
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