Sleep Deprivation and Sympathetic Neural Control in Older Adults

Abstract

Epidemiological studies have suggested a link between sleep deprivation and hypertension, and that this link is stronger in women. Our laboratory recently reported that baseline sympathetic neural responses to total sleep deprivation (TSD) were different in young men and women, with a greater shift towards sympathetic predominance in young women. Postmenopausal women are at high risk for hypertension. In the present study, we hypothesize that TSD will alter sympathetic neural activity in older adults, with greater sympathoexcitation in postmenopausal women. Nine participants between the ages of 55 and 75 years (9 women and 7 men) participated in the study. Subjects were tested twice one month apart, once after 24‐hour TSD and once after normal sleep. Wrist actigraphy was worn 5 days prior to each testing to confirm normal sleep patterns. We recorded muscle sympathetic nerve activity (MSNA; microneurography), beat‐to‐beat blood pressure (finger plethsmography), and heart rate (electrocardiogram) during 5 min of supine, awake rest. TSD elicited divergent MSNA responses in older men and women. Specifically, MSNA burst frequency increased in postmenopausal women (31±3 to 35±3 burst/min), but not older men (39±3 to 36±4 burst/min; time × condition, p = 0.036). This shift towards sympathetic predominance in women was also observed when MSNA was quantified as burst incidence (time × condition, p = 0.034). TSD did not alter baseline mean arterial pressure (men, 89±5 to 87±3 mmHg; women, 84±4 to 84±3) or heart rate (men, 55±3 to 55±4 beats/min; 58±3 to 60±4 beats/min) in either group (time, p>0.05; time × condition, p> 0.05). In summary, 24‐hour TSD elicits divergent MSNA responses in older men and women, with greater sympathoexcitation in postmenopausal women. These findings provide new mechanistic insight into reported links between sleep deprivation and hypertension.Support or Funding InformationFunding support from the National Institutes of Health (HL‐122919) and Portage Health Foundation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.