Researchers from Copenhagen University Hospital followed over 3,000 middle aged people over a period of 16 years, from 1985 to 2001. At the end of the study period, the researchers found that around 40 percent of the participants had died.
The researchers found that even an increase of ten and 22 beats a minute increased the risk of premature death by 16 percent. The researchers suggested that a rise in resting heart beat was linked with lower levels of physical fitness, higher blood pressure and weight and higher levels of circulating blood fats.
Says Dr Valerie Gladwell, senior lecturer in physiology at the University of Essex, who was not associated with the study, "According to this study, those individuals with a heart rate measured above 90 beats per minute appear to have a threefold increase in risk of death. This is interesting and may suggest that individuals with heart rates greater than 90 may be more susceptible to death, maybe due to an imbalance of their nervous system."