Chemo- and baroresponses differ in African-Americans and Caucasians in sleep.
To determine sleep effects on baro- and ventilatory responses to transient chemo- and barostimulation in African-Americans and Caucasians, 26 nonobese normotensive young subjects (13 African-Americans and 13 Caucasians) were studied awake and in non-rapid-eye movement (NREM) and rapid-eye-movement sleep during induced transient hypoxemia (N2), hypertension (phenylephrine, PE), and concomitant hypoxemia and hypertension (N2 + PE). Arterial blood pressure was recorded by plethysmographic volume clamp, minute ventilation by pneumotachograph, and arterial O2 saturation by pulse oximeter. For all subjects, chronotropic baroresponse (Deltapulse interval/Deltasystolic blood pressure, where Delta is change) increased with NREM sleep (P = 0.007). Baroresponse slope was greater in Caucasians than in African-Americans (ANOVA, P = 0.02). Hypoxemic ventilatory response (Deltaminute ventilation/Deltaarterial O2 saturation) was greater in African-Americans than in Caucasians in NREM sleep (P = 0.01), as was hypoxemic attenuation of baroresponse (N2 + PE, P = 0.03). These data suggest sleep-related differences in arterial chemo- and baroreceptor responses in normal young African-Americans and Caucasians, which may have implications concerning development of systemic hypertension.
Section of Respiratory and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago College of Medicine, and Department of Veterans Affairs West Side Medical Center and University of Illinois Hospital, Chicago, Illinois, USA.
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I
Crisostomo
A
A
Zayyad
D W
DW
Carley
J
J
Abubaker
E
E
Onal
E J
EJ
Stepanski
M
M
Lopata
R C
RC
Basner
D000328:Adult; D000704:Analysis of Variance; D044383:Black People; D001794:Blood Pressure; D015992:Body Mass Index; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D000860:Hypoxia; D007087:Illinois; D008297:Male; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D010656:Phenylephrine / Q000494:pharmacology; D010991:Plethysmography; D011311:Pressoreceptors / Q000187:drug effects / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology; D013599:Systole; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology; D044465:White People; D001741:Black or African American
D010656:Phenylephrine; D010100:Oxygen