title: Development of autonomic dysfunction with intermittent hypoxia in a lean murine model.
abstract: Intermittent hypoxia (IH) has been previously shown in a lean murine model to produce sustained hypertension and reverse the diurnal variation of blood glucose (BG). Concomitant glucose infusion attenuated the hypertension but exacerbated the BG fluctuations. In this study, cardiovascular variability analysis was employed to track the development of autonomic dysfunction in mice exposed to room air (IA) or IH, in combination with saline or glucose infusion. Baroreflex sensitivity was found to decrease in all animals, except in the control group. Low-frequency power of pulse interval spectrum, reflecting vagal activity, decreased more rapidly in glucose relative to saline while low-frequency power of blood pressure, reflecting sympathetic activity, decreased more slowly in IH relative to IA. Ultradian (≈ 12 h) rhythmicity was substantially suppressed in IH groups. These findings suggest that IH acted to increase sympathetic activity while glucose infusion led to reduced parasympathetic activity. The combination of IH and hyperglycemia leads to progressively adverse effects on autonomic control independent of obesity.
authors.affiliation: Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: P
authors.initials: P
authors.lastname: Chalacheva
authors.forename: J
authors.initials: J
authors.lastname: Thum
authors.forename: T
authors.initials: T
authors.lastname: Yokoe
authors.forename: C P
authors.initials: CP
authors.lastname: O'Donnell
authors.forename: M C K
authors.initials: MC
authors.lastname: Khoo
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001342:Autonomic Nervous System Diseases / Q000150:complications*; D017704:Baroreflex / Q000502:physiology*; D001786:Blood Glucose / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology; D004195:Disease Models, Animal; D006339:Heart Rate / Q000502:physiology*; D000860:Hypoxia / Q000150:complications*; D008297:Male; D051379:Mice; D013057:Spectrum Analysis; D013997:Time Factors
chemical_list: D001786:Blood Glucose
keywords: Autonomic function; Hyperglycemia; Intermittent hypoxia