Ronney B Panerai, Aaron Davies, Victoria J Haunton, Abdulaziz Alshehri, Emmanouil Katsogridakis, Lucy C Beishon, Thompson G Robinson, Jatinder S Minhas
{"title":"The influence of dynamic cerebral autoregulation efficiency on its directional sensitivity.","authors":"Ronney B Panerai, Aaron Davies, Victoria J Haunton, Abdulaziz Alshehri, Emmanouil Katsogridakis, Lucy C Beishon, Thompson G Robinson, Jatinder S Minhas","doi":"10.1152/ajpregu.00140.2025","DOIUrl":null,"url":null,"abstract":"<p><p>Dynamic cerebral autoregulation (dCA) demonstrates directional sensitivity (DS<sub>CA</sub>), depending on increases or reductions in mean arterial blood pressure (MAP). DS<sub>CA</sub> dependence on the efficiency of dCA has not been reported. A retrospective study of 172 healthy subjects (88 female, age 19-82 yr), with 5-min recordings of MAP, cerebral blood velocity (middle cerebral artery, MCAv), end-tidal CO<sub>2</sub>, and electrocardiogram, led to estimates of the MCAv step response to changes in MAP. The strength of DS<sub>CA</sub> was expressed by the difference between the MCAv step responses for the positive derivative component of MAP and the corresponding negative derivative component. The efficiency of dCA was expressed by the original autoregulation index (ARI<sub>orig</sub>), ranging from 0 to 9, calculated from the original MAP. For the entire population, DS<sub>CA</sub> strength was not associated with ARI<sub>orig</sub> or any other parameters. However, when taking biological sex and age into account, markers of DS<sub>CA</sub> strength showed significant linear regressions with ARI<sub>orig</sub>, with negative slopes for younger females (<i>P</i> = 0.0037-0.011, late phase of the step responses), no influence in older females (<i>P</i> > 0.69), and positive slopes for both younger and older males (early phase of the step responses, <i>P</i> = 0.003-0.041). This contrasting pattern of the influences of sex and age is in agreement with the known effects of gonadal hormones on the myogenic response and endothelial function of the cerebral circulation. Clinical studies of the diagnostic and/or prognostic value of DS<sub>CA</sub> parameters need to take into account the influences of sex, age, and the ARI<sub>orig</sub>.<b>NEW & NOTEWORTHY</b> Dynamic cerebral autoregulation (dCA) is more efficient for increases in mean arterial blood pressure (MAP) compared with reductions in MAP. We found that directional sensitivity of dCA is dependent on its efficiency, with differences depending on sex and age. In older women, strength of directional sensitivity (DS<sub>CA</sub>) is not affected by dCA efficiency, but in younger women, DS<sub>CA</sub> decreases with dCA efficiency, whereas in both younger and older men, DS<sub>CA</sub> strength increases with dCA efficiency.</p>","PeriodicalId":7630,"journal":{"name":"American journal of physiology. Regulatory, integrative and comparative physiology","volume":" ","pages":"R630-R642"},"PeriodicalIF":2.3000,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"American journal of physiology. Regulatory, integrative and comparative physiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1152/ajpregu.00140.2025","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/9/22 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"PHYSIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Dynamic cerebral autoregulation (dCA) demonstrates directional sensitivity (DSCA), depending on increases or reductions in mean arterial blood pressure (MAP). DSCA dependence on the efficiency of dCA has not been reported. A retrospective study of 172 healthy subjects (88 female, age 19-82 yr), with 5-min recordings of MAP, cerebral blood velocity (middle cerebral artery, MCAv), end-tidal CO2, and electrocardiogram, led to estimates of the MCAv step response to changes in MAP. The strength of DSCA was expressed by the difference between the MCAv step responses for the positive derivative component of MAP and the corresponding negative derivative component. The efficiency of dCA was expressed by the original autoregulation index (ARIorig), ranging from 0 to 9, calculated from the original MAP. For the entire population, DSCA strength was not associated with ARIorig or any other parameters. However, when taking biological sex and age into account, markers of DSCA strength showed significant linear regressions with ARIorig, with negative slopes for younger females (P = 0.0037-0.011, late phase of the step responses), no influence in older females (P > 0.69), and positive slopes for both younger and older males (early phase of the step responses, P = 0.003-0.041). This contrasting pattern of the influences of sex and age is in agreement with the known effects of gonadal hormones on the myogenic response and endothelial function of the cerebral circulation. Clinical studies of the diagnostic and/or prognostic value of DSCA parameters need to take into account the influences of sex, age, and the ARIorig.NEW & NOTEWORTHY Dynamic cerebral autoregulation (dCA) is more efficient for increases in mean arterial blood pressure (MAP) compared with reductions in MAP. We found that directional sensitivity of dCA is dependent on its efficiency, with differences depending on sex and age. In older women, strength of directional sensitivity (DSCA) is not affected by dCA efficiency, but in younger women, DSCA decreases with dCA efficiency, whereas in both younger and older men, DSCA strength increases with dCA efficiency.
期刊介绍:
The American Journal of Physiology-Regulatory, Integrative and Comparative Physiology publishes original investigations that illuminate normal or abnormal regulation and integration of physiological mechanisms at all levels of biological organization, ranging from molecules to humans, including clinical investigations. Major areas of emphasis include regulation in genetically modified animals; model organisms; development and tissue plasticity; neurohumoral control of circulation and hypertension; local control of circulation; cardiac and renal integration; thirst and volume, electrolyte homeostasis; glucose homeostasis and energy balance; appetite and obesity; inflammation and cytokines; integrative physiology of pregnancy-parturition-lactation; and thermoregulation and adaptations to exercise and environmental stress.