Polymorphism -786T>C (rs2070744) of the NOS3 gene as a potential risk factor for impaired autonomic regulation of the cardiovascular system in the age aspect

According to current understanding, aging is a complex process that is influenced by both genetic and environmental factors. Identifying reliable indicators of healthy aging is a significant challenge for modern science. Previous research has shown that aging is linked to a gradual decrease in HRV (heart rate variability). The aim is to analyze age-related alterations in the autonomic control of the cardiovascular system, taking into consideration different variants of the -786T>C polymorphism in the NOS3 gene, based on heart rate variability characteristics. A cross-sectional study was conducted on a sample of 245 northern men, which were divided into three age groups: group 1 - boys (n=109, average age 18,3±0,3 years), group 2 - mature men (n=97, average age 39,5±0,8 years), and group 3 - elderly men (n=39, average age 65,5±1,5 years). The -786T>C polymorphism (rs 2070744) of the NOS3 gene was genotyped using real-time polymerase chain reaction with commercial SNP-Screen kits («Syntol», Russia). Heart rate variability was recorded using the Varicard complex software («VARICARD-KARDi», Russia), and a number of heart rate variability parameters in the time and frequency range were measured. For all heart rate variability parameters that reflect the activity of the parasympathetic branch of the autonomic nervous system, an age-related decrease was observed. However, the rate of this decline varied depending on the variant of the NOS3 gene polymorphism. The maximum decrease in heart rate variability parameters was seen in individuals with the functionally weaker NOS3*C allele (those with TC+CC genotypes). Given the age-related nature of heart rate variability, its use for prognostic purposes necessitates an understanding of normal ranges in different age groups, including consideration of associations with the -786T>C (rs2070744) polymorphism of NOS3 gene. The presence of the TT genotype has been linked to a more favorable, vagus-mediated heart rate variability profile and can be regarded as a predictor for reduced risk of cardiovascular disease.