Resilience to orthostasis and haemorrhage: A pilot study of common genetic and conditioning mechanisms

Abstract

A major challenge presently is not only to identify the genetic polymorphisms increasing risk to diseases, but to also find out factors and mechanisms, which can counteract a risk genotype by developing a resilient phenotype. The objective of this study was to examine acquired and innate vagal mechanisms that protect against physical challenges and haemorrhages in 19 athletes and 61 non-athletes. These include examining change in heart rate variability (HF-HRV; an indicator of vagus activity) in response to orthostatic challenge, platelet count (PLT), mean platelet volume (MPV), and single-nucleotide polymorphisms in genes that encode several coagulation factors, PAI-1, and MTHFR. Individual differences in PLT and MPV were significant predictors, with opposite effects, of the profiles of the HF-HRV changes in response to orthostasis. Regular physical training of athletes indirectly (through MPV) modifies the genetic predisposing effects of some haemostatic factors (PAI-1 and MTHFR) on vagal tone and reactivity. Individual differences in vagal tone were also associated with relationships between Factor 12 C46T and Factor 11 C22771T genes polymorphisms. This study showed that genetic predispositions for coagulation are modifiable. Its potential significance is promoting advanced protection against haemorrhages in a variety of traumas and injuries, especially in individuals with coagulation deficits.

Asymmetries in reciprocal baroreflex mechanisms and chronic pain severity: Focusing on irritable bowel syndrome

“…Pain‐related effect on the baroreflex symmetry mechanism, which diminishes tachycardiac baroreflex in response to BP decrease (a putative “pain resilience” mechanism) may determine, as a byproduct, the symptoms of OI and POTS in some patients as one of multiple distinct pathophysiological subtypes within them . Its resilience attribute is concordant with findings of increased orthostatic heart rate response as a biomarker of more universal mechanism of protection against negative affect, chronic pain, and hemorrhage severity . Chronic pain is also frequently co‐morbid with arterial hypertension .…”

“…87 Its resilience attribute is concordant with findings of increased orthostatic heart rate response as a biomarker of more universal mechanism of protection against negative affect, chronic pain, and hemorrhage severity. 18,62,88 Chronic pain is also frequently co-morbid with arterial hypertension. 89 Pain-related effect on the baroreflex symmetry mechanism, which increases start point for bradycardiac baroreflex in response to BP increase (a putative "pain adaptation" mechanism) may determine, as a byproduct, a chronically elevated BP level in some patients.…”

Cardiovascular phenotyping for personalized lifestyle treatments of chronic abdominal pain in Irritable Bowel Syndrome: A randomized pilot study

“…A percentile bootstrap procedure with 5000 bootstrap samples was used to generate 95% confidence intervals (CIs) of regression coefficients from empirical sampling distribution in GLM and mediation analyses. The bootstrap procedure was suggested as a robust alternative to inference based on parametric assumptions (such as normally distributed errors) to confirm findings obtained by parametric analyses and is recommended for reporting inferences in scientific reports . All parameter estimates were expressed as non‐standardized (B) regression coefficients and their standard errors (SE) in the text.…”

“…This suggests that both across individuals and interventions autonomic responses may serve as predictors or early indicators of chronic pain treatment response depending on individual phenotype and treatment targets. For example, walking and other methods stimulating aerobic physical activity seem to improve health through motor (efferent) division of the nervous system . Yoga and other techniques increasing body and mind relaxation seem to improve psychosomatic health through sensory (afferent) division of the nervous system .…”

Baroreflex mechanisms in Irritable Bowel Syndrome: Part I. Traditional indices

“…Bias-corrected and accelerated (BCa) bootstrap procedure with 5000 bootstrap samples was used to generate non-parametric 95% confidence intervals (CIs) of regression coefficients from empirical sampling distribution. The bootstrap procedure was suggested as a robust alternative to inference based on parametric assumptions (such as normally distributed errors) to confirm findings obtained by parametric analyses and is recommended for reporting inferences in scientific reports [34,35]. All parameter estimates were expressed as non-standardized (B) regression coefficients and their standard errors (SE) in the text.…”