Your heart rate is influenced by many different factors like how fit you are, when your last cup of coffee was, or doing something stressful like public speaking. Perhaps it isn’t surprising, then, that we need to look at more than one genetic variant to give you information about how your DNA affects your heart rate!
When heart rate was studied in over 180,000 people, 21 different variants were significantly associated with heart rate. This means that the presence of a specific letter (A,T,C, or G) at a specific position in the genome was more common in people with higher heart rate. Rather than choosing just one of these variants to tell you about how your DNA affects your heart rate, we add them together to calculate your result.
Each one of these 21 SNPs has two possible versions—a version that increases heart rate and a version that does not. We look at each variant and determine the overall balance of increasing and non-increasing versions you have.
Researchers using this approach were able to show that people who were in the top 5% had a resting heart rate that was on average 2 beats per minute faster than people who weren’t in the top 5%. Similarly, people who were in the bottom 5% of heart rate increasing versions had a resting heart rate that was on average 2 beats per minute slower than people who weren’t in the bottom 5%.
Your result can’t tell you exactly what your resting heart rate is at this moment, or any other. But it can give you a sense of how genetics might contribute to that value by potentially influencing it by just a few beats.