An international study led by academics from Vrije Universiteit Amsterdam (VU) and the University Medical Center Groningen (UMCG) is the first to find genes that influence the beat-to-beat variability of the heart. The genes that cause a low variation in heart rate also appear to increase the resting heart rate and blood pressure, two risk factors for cardiovascular disease. Nature Communications publishes the outcome of this research today.
Low heart rate variability rate is a predictor of cardiovascular disease, still one of the most common causes of death. The results increase our understanding of differences between people’s autonomic nervous system, which plays a key role in the occurrence of stress. The genes that the scientists discovered influence the body’s autonomic nerve, which slows the heart rate after excitement and exertion. In a healthy person, there is great variation in time between two heart beats. The higher the variation in heart rate, the lower the chance of cardiovascular disease.
Relationship between heart rate and blood pressure
Principal investigator Ilja Nolte (UMCG): ‘We found genetic variants in eight areas of the human genome, so we can now say with great certainty that they influence the variation in time between two heart beats (heart rate variability). Two of the genes regulate the firing frequency of pacemaker cells in the right atrium of the heart. They produce proteins that play a role in the transmission of the signals that travel through the nerves of the brain to the heart and can cause beat-to-beat variation in the heart rate.’
According to UMCG professor Harold Snieder, the clear relationship between genetic variants for heart rate variability and blood pressure represents a breakthrough: ‘This confirms the theory that the autonomic nervous system plays a significant role in the development of high blood pressure.’ The genetic variants that influence heart rate variability do not appear to be any different in people with ancestors from Africa or Latin America than in people with European ancestors. In the study, over 53,000 participants from Europe and the United States underwent an ECG and provided blood samples or cheek swabs for DNA testing.
Physical and mental health
VU professor Eco de Geus believes that these findings may also make it possible to investigate current expectations of the role of autonomic nerve activity in physical and mental health. De Geus: ‘Particularly if we combine the findings with research in our Netherlands Twin Register, where we have a great deal of information on the genes of a large group of people. These results should make it possible to test cause and effect relationships without conducting expensive experimental research.’