Differences In Heart Rate Variability (HRV), Coherence, And Stress Scores By Covid-19 Vaccination Status

HRV is an indicator of autonomic function, inflammation, and autonomic dysfunction. Evidence suggests an inverse relationship between HRV (SDNN standard deviation of NN intervals) and inflammation, with multiple reports indicating COVID-19 vaccination (vac) related to ANS dysfunction. The vac effect is not fully known, some reporting it incites inflammation while others found the effects were temporary. Given the conflicting results, additional research is needed. PURPOSE: Identify differences in HRV, coherence (a state of physiological function shifted toward parasym. activity), and stress index scores between students enrolled in a health/wellness course who did (n = 44) and did not (n = 23) receive COVID-19 vac. Timing of the vac related to data collected was not determined nor were non-vac subjects asked of exposure or infection with COVID. METHODS: Biometric data (ht, wt, body comp, mile walk VO2 (ml/kg/min), HRV, and stress health risk appraisal was collected at the beginning and end of semester on 67 subjects. HRV was collected using an infrared pulse plethysmograph ear sensor. Subjects completed the State-Trait Anxiety Inventory for Adults receiving a Stress Index score. Lifestyle education (breathing tech., attitude, and heart-brain connection (coherence)) and exercise were the primary focus of the curriculum. Mixed-Design Multivariate ANOVA was used to examine associations. RESULTS: There was a stat. sig. difference in R-R intervals between group and time (F(1,65) = 6.577, p = 0.013). The vac group had a greater increase than non-vac group. VO2 was stat. sig. from pre-to post-test (F(1,65) = 12.894, p = <0.001). While the non-vac group had a greater HRV at pre-test, their HRV did not increase at post-test but the vac group did. There were no stat. sig. differences for coherence or stress index. CONCLUSIONS: Results suggest improvement in VO2. While no difference between groups or from pre- to post-test for HRV, coherence, or stress index it should be emphasized that this health education course significantly improved VO2. While the literature is clear that vac produces at least acute inflammation which would decrease HRV, the literature is not as clear as to the long-term effects of vac. These results are more in line with Kerkutluoglu et. al that identify the decline in HRV following vac was temporary.