The impact of age, sex, cardio-respiratory fitness, and cardiovascular disease risk on dynamic cerebral autoregulation and baroreflex sensitivity

Abstract

Background Humans display an age-related decline in cerebral blood flow and increase in blood pressure (BP), but changes in the underlying control mechanisms across the lifespan are less well understood. We aimed to; (1) examine the impact of age, sex, cardiovascular disease (CVD) risk, and cardio-respiratory fitness on dynamic cerebral autoregulation and cardiac baroreflex sensitivity, and (2) explore the relationships between dynamic cerebral autoregulation (dCA) and cardiac baroreflex sensitivity (cBRS). Methods 206 participants aged 18–70 years were stratified into age categories. Cerebral blood flow velocity was measured using transcranial Doppler ultrasound. Repeated squat-stand manoeuvres were performed (0.10 Hz), and transfer function analysis was used to assess dCA and cBRS. Multivariable linear regression was used to examine the influence of age, sex, CVD risk, and cardio-respiratory fitness on dCA and cBRS. Linear models determined the relationship between dCA and cBRS. Results Age, sex, CVD risk, and cardio-respiratory fitness did not impact dCA normalised gain, phase, or coherence with minimal change in all models (P > 0.05). cBRS gain was attenuated with age when adjusted for sex and CVD risk (young–older; β = − 2.86 P < 0.001) along with cBRS phase (young–older; β = − 0.44, P < 0.001). There was no correlation between dCA normalised gain and phase with either parameter of cBRS. Conclusion Ageing was associated with a decreased cBRS, but dCA appears to remain unchanged. Additionally, our data suggest that sex, CVD risk, and cardio-respiratory fitness have little effect.

Cerebral blood velocity during concurrent supine cycling, lower body negative pressure, and head-up tilt challenges: implications for concussion rehabilitation

“…Nonetheless, pilot work from the author group has demonstrated the orthostatic challenge applied in the current investigation is minimally influenced by the menstrual cycle phase. Previous work has noted autoregulatory capabilities are not different between younger and older populations (Smirl et al 2015, Carey et al 2000, Maxwell et al 2022; however, orthostatic intolerance is known to become more prevalent with increasing age (Rutan et al 1992). Therefore, the current study warrants further exploration across adulthood and within the elderly.…”

A decade of aging in healthy older adults: longitudinal findings on cerebrovascular and cognitive health

“…We found that a decade of healthy aging from ~ 70 to ~ 80 years old did not change cerebral autoregulation, which is important as most previous studies that examined the impact of age on CA adopted a cross-sectional design. These studies typically found preserved CA in older adults [23][24][25], with only one study reporting elevated transfer function gain (but not phase) in the oldest participants [26]. To our knowledge, only one other study adopted longitudinal follow-up and found a decrease in autoregulation index in ten middle-aged subjects (24-51 years at baseline) across 10-year follow-up [27].…”

Cerebrovascular CO2 reactivity and dynamic cerebral autoregulation through the eighth decade of life and their implications for cognitive decline

“…While it is often suggested that aging is accompanied by impaired dCA, for example because age-related diseases such as stroke or dementia have been associated with impaired autoregulation, emerging evidence suggests that dCA remains intact in advanced age stages. 9,15,26 Importantly however, the majority of previous work was limited to cohort studies and cross-sectional evidence, hence subject to various sources of bias. Therefore, our long-term follow-up study contributes to a better understanding of the true effects of healthy aging within individuals.…”