Luke A Henderson1,2, Vaughan G Macefield3. 1. Discipline of Anatomy and Histology, Sydney Medical School, University of Sydney, Sydney, Australia. lukeh@anatomy.usyd.edu.au. 2. Department of Anatomy and Histology, F13, University of Sydney, Sydney, Australia. lukeh@anatomy.usyd.edu.au. 3. School of Medicine, University of Western Sydney, Sydney, Australia.
Abstract
PURPOSE OF REVIEW: Obstructive sleep apnoea (OSA) is associated with both nocturnal and daytime hypertensions which increase cardiovascular morbidity and mortality. It is thought that the repeated episodes of hypoxia and hypercapnia during nocturnal airway obstructions that characterise OSA result in increased sympathetic drive that persists during wakefulness. Although the underlying mechanisms responsible for this hypertension remain to be elucidated, several neural and humoral mechanisms have been proposed and recent evidence suggesting changes in the central nervous system may play a significant role. The purpose of this review is to explore recent evidence of central changes associated with elevated sympathetic drive in individuals with OSA. RECENT FINDINGS: Recent human brain imaging investigations and, in particular, combined microneurography recording of resting sympathetic activity with high-resolution functional magnetic resonance imaging have provided some important insights into changes in brain function and anatomy associated with resting sympathetic activity. Functional and anatomical changes occur in OSA, including in regions of the brainstem circuitry known to be responsible for setting resting sympathetic activity. Furthermore, these changes are reversed following continuous positive airway treatment in concert with reductions in resting sympathetic drive. These resent findings suggest that the central changes may contribute significantly to the hypertension associated with OSA.
PURPOSE OF REVIEW: Obstructive sleep apnoea (OSA) is associated with both nocturnal and daytime hypertensions which increase cardiovascular morbidity and mortality. It is thought that the repeated episodes of hypoxia and hypercapnia during nocturnal airway obstructions that characterise OSA result in increased sympathetic drive that persists during wakefulness. Although the underlying mechanisms responsible for this hypertension remain to be elucidated, several neural and humoral mechanisms have been proposed and recent evidence suggesting changes in the central nervous system may play a significant role. The purpose of this review is to explore recent evidence of central changes associated with elevated sympathetic drive in individuals with OSA. RECENT FINDINGS: Recent human brain imaging investigations and, in particular, combined microneurography recording of resting sympathetic activity with high-resolution functional magnetic resonance imaging have provided some important insights into changes in brain function and anatomy associated with resting sympathetic activity. Functional and anatomical changes occur in OSA, including in regions of the brainstem circuitry known to be responsible for setting resting sympathetic activity. Furthermore, these changes are reversed following continuous positive airway treatment in concert with reductions in resting sympathetic drive. These resent findings suggest that the central changes may contribute significantly to the hypertension associated with OSA.
Authors: Linda C Lundblad; Rania H Fatouleh; Elie Hammam; David K McKenzie; Vaughan G Macefield; Luke A Henderson Journal: Neuroimage Date: 2014-09-22 Impact factor: 6.556
Authors: Paul M Macey; Manoj K Sarma; Rajakumar Nagarajan; Ravi Aysola; Jerome M Siegel; Ronald M Harper; M Albert Thomas Journal: J Sleep Res Date: 2016-02-04 Impact factor: 3.981
Authors: Luke A Henderson; Rania H Fatouleh; Linda C Lundblad; David K McKenzie; Vaughan G Macefield Journal: Front Neurosci Date: 2016-03-10 Impact factor: 4.677
Authors: Amrita Pal; Jennifer A Ogren; Andrea P Aguila; Ravi Aysola; Rajesh Kumar; Luke A Henderson; Ronald M Harper; Paul M Macey Journal: Sleep Date: 2021-01-21 Impact factor: 5.849
Authors: Reena Mehra; Olga A Tjurmina; Olujimi A Ajijola; Rishi Arora; Donald C Bolser; Mark W Chapleau; Peng-Sheng Chen; Colleen E Clancy; Brian P Delisle; Michael R Gold; Jeffrey J Goldberger; David S Goldstein; Beth A Habecker; M Louis Handoko; Robert Harvey; James P Hummel; Thomas Hund; Christian Meyer; Susan Redline; Crystal M Ripplinger; Marc A Simon; Virend K Somers; Stavros Stavrakis; Thomas Taylor-Clark; Bradley Joel Undem; Richard L Verrier; Irving H Zucker; George Sopko; Kalyanam Shivkumar Journal: JACC Basic Transl Sci Date: 2022-01-26