title: Sympathetic neural adaptation to hypocaloric diet with or without exercise training in obese metabolic syndrome subjects.
abstract: OBJECTIVE
  Sympathetic nervous system (SNS) overactivity contributes to the pathogenesis and target organ complications of obesity. This study was conducted to examine the effects of lifestyle interventions (weight loss alone or together with exercise) on SNS function.
  
  
  METHODS
  Untreated men and women (mean age 55 +/- 1 year; BMI 32.3 +/- 0.5 kg/m(2)) who fulfilled Adult Treatment Panel III metabolic syndrome criteria were randomly allocated to either dietary weight loss (WL, n = 20), dietary weight loss and moderate-intensity aerobic exercise (WL+EX, n = 20), or no treatment (control, n = 19). Whole-body norepinephrine kinetics, muscle sympathetic nerve activity by microneurography, baroreflex sensitivity, fitness (maximal oxygen consumption), metabolic, and anthropometric measurements were made at baseline and 12 weeks.
  
  
  RESULTS
  Body weight decreased by -7.1 +/- 0.6 and -8.4 +/- 1.0 kg in the WL and WL+EX groups, respectively (both P < 0.001). Fitness increased by 19 +/- 4% (P < 0.001) in the WL+EX group only. Resting SNS activity decreased similarly in the WL and WL+EX groups: norepinephrine spillover by -96 +/- 30 and -101 +/- 34 ng/min (both P < 0.01) and muscle sympathetic nerve activity by -12 +/- 6 and -19 +/- 4 bursts/100 heart beats, respectively (both P < 0.01), but remained unchanged in control subjects. Blood pressure, baroreflex sensitivity, and metabolic parameters improved significantly and similarly in the two lifestyle intervention groups.
  
  
  CONCLUSIONS
  The addition of moderate-intensity aerobic exercise training to a weight loss program does not confer additional benefits on resting SNS activity. This suggests that weight loss is the prime mover in sympathetic neural adaptation to a hypocaloric diet.
authors.affiliation: Human Neurotransmitters Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia. nora.straznicky@bakeridi.edu.au
authors.forename: Nora E
authors.initials: NE
authors.lastname: Straznicky
authors.forename: Elisabeth A
authors.initials: EA
authors.lastname: Lambert
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Nestel
authors.forename: Mariee T
authors.initials: MT
authors.lastname: McGrane
authors.forename: Tye
authors.initials: T
authors.lastname: Dawood
authors.forename: Markus P
authors.initials: MP
authors.lastname: Schlaich
authors.forename: Kazuko
authors.initials: K
authors.lastname: Masuo
authors.forename: Nina
authors.initials: N
authors.lastname: Eikelis
authors.forename: Barbora
authors.initials: B
authors.lastname: de Courten
authors.forename: Justin A
authors.initials: JA
authors.lastname: Mariani
authors.forename: Murray D
authors.initials: MD
authors.lastname: Esler
authors.forename: Florentia
authors.initials: F
authors.lastname: Socratous
authors.forename: Reena
authors.initials: R
authors.lastname: Chopra
authors.forename: Carolina I
authors.initials: CI
authors.lastname: Sari
authors.forename: Eldho
authors.initials: E
authors.lastname: Paul
authors.forename: Gavin W
authors.initials: GW
authors.lastname: Lambert
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000332:Aerobiosis; D001794:Blood Pressure; D049628:Body Size; D001835:Body Weight; D004038:Diet, Reducing; D015444:Exercise; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D009638:Norepinephrine / Q000378:metabolism; D009765:Obesity / Q000150:complications / Q000503:physiopathology / Q000534:rehabilitation*; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D016896:Treatment Outcome
chemical_list: D009638:Norepinephrine