A climbing heart rate over several years could signal a shorter lifespan in middle-aged men, French researchers have found.
Dr. Xavier Jouven, a cardiologist at the Georges Pompidou European Hospital in Paris, says that of the two basic heart-related measurements done in the family doctor’s office – pulse and blood pressure – the latter has received most of the attention over the past several decades.
“During the same time, we did not look at heart rate as a risk factor,” Jouven says. “And in fact we underestimate … the role of heart rate as a potential risk factor.”
He says previous research has shown a high resting heart rate – the pulse measured when the body is at rest – is associated with a higher risk of death, but his is the first study to link changes in heart rate over a period of years with mortality risk.
The study involved 4,320 men ages 42 to 53 years who were recruited between 1967 and 1972 and had yearly standardized physical examinations over the next five years. Doctors determined heart rate by measuring the men’s pulse at the wrist over one minute, after the patients had rested on their back for five minutes.
During a followup of more than 20 years, 1,018 men died from various causes. After adjusting for other heart disease risk factors, the researchers found that men whose resting heart rate increased by more than seven beats per minute were 47 per cent more likely to have died than men whose heart rate remained relatively stable. In contrast, men whose resting heart rate decreased by more than seven beats per minute had an 18 per cent lower mortality rate.
Jouven says the changes in heart rate could at least partly be explained by changes in physical activity, but the researchers were unable to track this over time.
The benefits of a drop in heart rate were most evident in men who had a heart rate of more than 75 beats per minute to begin with. If their pulse remained relatively stable over five years, their long-term mortality risk was 79 per cent higher than men with a stable heart rate of 61 to 75 beats per minute. But those who decreased their heart rate by more than seven beats per minute had a mortality rate that was not significantly different from this group