title: Effect of weight gain on cardiac autonomic control during wakefulness and sleep.
abstract: Obesity has been associated with increased cardiac sympathetic activation during wakefulness, but the effect on sleep-related sympathetic modulation is not known. The aim of this study was to investigate the effect of fat gain on cardiac autonomic control during wakefulness and sleep in humans. We performed a randomized, controlled study to assess the effects of fat gain on heart rate variability. We recruited 36 healthy volunteers, who were randomized to either a standardized diet to gain ≈4 kg over 8 weeks followed by an 8-week weight loss period (n=20) or to serve as a weight-maintainer control (n=16). An overnight polysomnogram with power spectral analysis of heart rate variability was performed at baseline, after weight gain, and after weight loss to determine the ratio of low-frequency to high-frequency power and to examine the relationship between changes in heart rate variability and changes in insulin, leptin, and adiponectin levels. Mean weight gain was 3.9 kg in the fat gain group versus 0.1 kg in the maintainer group. Low frequency/high frequency increased both during wakefulness and sleep after fat gain and returned to baseline after fat loss in the fat gain group and did not change in the control group. Insulin, leptin, and adiponectin also increased after fat gain and fell after fat loss, but no clear pattern of changes was seen that correlated consistently with changes in heart rate variability. Short-term fat gain in healthy subjects is associated with increased cardiac sympathetic activation during wakefulness and sleep, but the mechanisms remain unclear.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, 200 First St SW, Rochester, MN 55905. somers.virend@mayo.edu.
authors.forename: Taro
authors.initials: T
authors.lastname: Adachi
authors.forename: Fatima H
authors.initials: FH
authors.lastname: Sert-Kuniyoshi
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Calvin
authors.forename: Prachi
authors.initials: P
authors.lastname: Singh
authors.forename: Abel
authors.initials: A
authors.lastname: Romero-Corral
authors.forename: Christelle
authors.initials: C
authors.lastname: van der Walt
authors.forename: Diane E
authors.initials: DE
authors.lastname: Davison
authors.forename: Jan
authors.initials: J
authors.lastname: Bukartyk
authors.forename: Tomas
authors.initials: T
authors.lastname: Konecny
authors.forename: Snigdha
authors.initials: S
authors.lastname: Pusalavidyasagar
authors.forename: Justo
authors.initials: J
authors.lastname: Sierra-Johnson
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
mesh_terms: D000293:Adolescent; D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D001786:Blood Glucose; D001823:Body Composition / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*; D015430:Weight Gain / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D020738:Leptin