Summary: New research suggests that inherited genetic differences can shape how heart rate and blood pressure respond to exercise, potentially signaling long-term cardiovascular risk.
Source: The Physiological Society.
Genetic variants in skeletal muscle receptors influence blood pressure and heart rate responses to exercise, and may help identify individuals at increased risk for future cardiovascular conditions, according to new research published in The Journal of Physiology.
It is normal for heart rate and blood pressure to rise during physical activity, but the degree of change varies widely between individuals. Prior studies have linked unusually large blood pressure increases during exercise with a greater likelihood of developing chronic hypertension later in life. Understanding the reasons for these individual differences is therefore important for identifying at-risk people and enabling early monitoring or intervention.
This recent study points to inherited differences in muscle sensory receptors as one contributing factor. Receptors located in skeletal muscle detect metabolic and mechanical changes during contraction and send signals to the cardiovascular control system. The researchers found that two common single-nucleotide polymorphisms (SNPs) in these receptors were associated with larger blood pressure responses during exercise, particularly in men.
The investigation, led by scientists at the University of Guelph (Canada), measured continuous heart rate and blood pressure in 200 healthy young adults before and during a brief static handgrip exercise. Participants also provided DNA samples for genotyping to identify specific receptor polymorphisms. The handgrip task used a 2-minute contraction at 30% of each participant’s maximal voluntary effort, followed by circulatory occlusion and a standardized mental stress test as an internal control.
Although the study is limited by its sample size and by the use of a single static exercise model, the associations with receptor variants were statistically significant. Further research will be needed to confirm these findings across different exercise types, larger cohorts, and diverse populations.
Philip J. Millar, corresponding author of the study, noted: “These results suggest that specific receptor variants can contribute to larger blood pressure responses during exercise—a trait that is linked to future risk to the heart and blood vessels. It is important to investigate why these effects were stronger in men and to determine the mechanisms through which these genetic variants alter cardiovascular reflexes during physical activity.”
Source: Andrew Mackenzie — The Physiological Society
Publisher: Organized by Neuroscience News.
Image source: Public domain image credited in the original article.
Original research: Abstract for “TRPV1 and BDKRB2 receptor polymorphisms can influence the exercise pressor reflex” by Karambir Notay, Shannon L. Klingel, Jordan B. Lee, Connor J. Doherty, Jeremy D. Seed, Michal Swiatczak, David M. Mutch, and Philip J. Millar in The Journal of Physiology. Published September 11, 2018. doi: 10.1113/JP276526
MLA: The Physiological Society. “Your Genes Determine How Your Heart Rate Responds to Exercise.” Neuroscience News, 12 September 2018.
APA: The Physiological Society (2018, September 12). Your Genes Determine How Your Heart Rate Responds to Exercise. Neuroscience News.
Chicago: The Physiological Society. “Your Genes Determine How Your Heart Rate Responds to Exercise.” Neuroscience News, September 12, 2018.
Abstract
TRPV1 and BDKRB2 receptor polymorphisms can influence the exercise pressor reflex
Individual variability in blood pressure responses to exercise may be driven in part by differences in metabolically sensitive afferent feedback from contracting skeletal muscle. This study tested whether single-nucleotide polymorphisms in genes that code for metaboreceptors on group III/IV muscle afferents influence the pressor response to static exercise. Two hundred men and women underwent continuous blood pressure and heart rate monitoring at baseline and during a 2-minute static handgrip at 30% maximal voluntary contraction, followed by post-exercise circulatory occlusion and a serial subtraction mental stress task as an internal control. Participants were genotyped for SNPs in TRPV1 (rs222747; G/C), ASIC3 (rs2288645; G/A), BDKRB2 (rs1799722; C/T), PTGER2 (rs17197; A/G), and P2RX4 (rs25644; A/G).
Key findings included lower exercise systolic blood pressure in GG homozygotes compared with GC/CC carriers for TRPV1 rs222747, and lower exercise diastolic blood pressure and heart rate in CC homozygotes versus CT/TT carriers for BDKRB2 rs1799722. Individuals carrying minor alleles for both TRPV1 rs222747 and BDKRB2 rs1799722 exhibited larger increases in systolic and diastolic blood pressure during exercise than those without these alleles; these additive differences were more pronounced in men. No significant associations were observed for ASIC3 rs2288645, PTGER2 rs17197, or P2RX4 rs25644, and none of the tested SNPs correlated with responses to mental stress. These results suggest that TRPV1 and BDKRB2 receptor variants can contribute additively to blood pressure responses during static exercise.