Journal article
Aging and sympathetic transduction to blood pressure in humans: methodological and physiological considerations
American journal of physiology. Heart and circulatory physiology, Vol.326(1), pp.H148-H157
01/01/2024
DOI: 10.1152/ajpheart.00359.2023
PMID: 37921667
Abstract
Recent reports suggest that quantification of signal-averaged sympathetic transduction is influenced by resting muscle sympathetic nerve activity (MSNA) and burst occurrence relative to the average mean arterial pressure (MAP). Herein, we asked how these findings may influence age-related reductions in sympathetic transduction. Beat-to-beat blood pressure and MSNA were recorded during 5 min of rest in 27 younger (13 females: age, 25 ± 5 yr; BMI, 25 ± 4 kg/m
) and 26 older (15 females: age, 59 ± 5 yr; BMI, 26 ± 4 kg/m
) healthy adults. All MSNA bursts were signal averaged together. Beat-to-beat MAP values were then split into low (T1), middle (T2), and high (T3) tertiles, and signal-averaged transduction was calculated within each tertile. Resting MSNA was higher in older adults and MAP was similar between groups. Older adults exhibited blunted overall MAP transduction (younger, Δ1.5 ± 0.6 vs. older, Δ0.9 ± 0.7 mmHg;
= 0.005), which was irrespective of relation to prevailing MAP. A greater proportion of bursts occurred above the average MAP in older adults (
< 0.001), and a larger proportion of these bursts were associated with depressor responses (
= 0.005). Nonetheless, assessment of bursts above the average MAP associated with pressor responses revealed similar age-associated reductions in transduction (younger, Δ2.6 ± 1.6 vs. older, Δ1.7 ± 0.8 mmHg;
= 0.016). These findings indicate an age-related increase in burst occurrence above the average resting MAP, which alone does not explain blunted transduction, thereby supporting the physiological underpinnings of age-related decrements in sympathetic transduction to blood pressure.
The current study demonstrated that aging is associated with a greater prevalence of sympathetic bursts occurring above the average blood pressure, which offers both methodologically and physiologically relevant information regarding aging and sympathetic control of blood pressure. These data support age-related reductions in sympathetic transduction via a reduced pressor response to sympathetic bursts irrespective of the prevailing absolute blood pressure value, along with increases in sympathetic outflow necessary to maintain blood pressure.
Details
- Title: Subtitle
- Aging and sympathetic transduction to blood pressure in humans: methodological and physiological considerations
- Creators
- Jeremy A Bigalke - Baylor UniversityBenjamin E Young - The University of Texas at ArlingtonEmily L Cleveland - Montana State UniversityPaul J Fadel - The University of Texas at ArlingtonJason R Carter - Baylor University
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Heart and circulatory physiology, Vol.326(1), pp.H148-H157
- DOI
- 10.1152/ajpheart.00359.2023
- PMID
- 37921667
- NLM abbreviation
- Am J Physiol Heart Circ Physiol
- ISSN
- 0363-6135
- eISSN
- 1522-1539
- Grant note
- R01 AA024892 / NIAAA NIH HHS AA-0024892 / HHS | National Institutes of Health (NIH)
- Language
- English
- Date published
- 01/01/2024
- Academic Unit
- Health, Sport, and Human Physiology
- Record Identifier
- 9985219861602771
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