title: Autonomic nervous system activity in diabetic and healthy obese female subjects and the effect of distinct weight loss strategies.
abstract: OBJECTIVE
  Obesity and type 2 diabetes mellitus (T2DM) are reported to be associated with relative overactivity of the sympathetic nervous system (SNS), which is reversible by weight loss. However, direct effects of weight loss by calorie restriction vs Roux-en-Y gastric bypass (RYGB) on SNS overactivity were not studied in parallel. This study compared the effects of RYGB vs restrictive weight loss in obese patients with normal glucose tolerance (NGT) and with T2DM on SNS function as measured by heart rate variability (HRV).
  
  
  METHODS
  Lean (n=12), obese NGT (n=27) and T2DM (n=27) subjects were included in this study. Weight reduction in NGT subjects was achieved by gastric banding (GB) or RYGB and in T2DM subjects by RYGB or high-protein very-low-calorie diet (VLCD). HRV analysis was performed and blood samples were taken at baseline, 3 weeks and 3 months after intervention.
  
  
  RESULTS
  At baseline, T2DM subjects showed SNS overactivity and NGT subjects showed similar, but non-significant, findings when compared with lean controls. Weight loss after 3 weeks was comparable in all treatment groups, whereas after 3 months, weight loss was most in VLCD and RYGB subjects. RYGB and VLCD treatment reduced SNS activity within 3 weeks in T2DM patients. After 3 months, restoration to normal autonomic nervous system activity was evident for all groups, except for the NGT-GB group.
  
  
  CONCLUSIONS
  We can conclude that SNS overactivity is more pronounced in obese T2DM subjects when compared with NGT subjects. Reduction of SNS overactivity coincides with weight loss with the time-course of reduction dependent on the type of intervention. Surgery or caloric restriction may transiently induce SNS overactivity but do not prevent a direct restoration of sympathovagal balance.
authors.affiliation: Department of Endocrinology and Metabolism, Leiden University Medical Center, C-04-R-83, Albinusdreef 2, PO Box 9600, 2333 ZA Leiden, The Netherlands.
authors.forename: Mirjam A
authors.initials: MA
authors.lastname: Lips
authors.forename: Gerrit H
authors.initials: GH
authors.lastname: de Groot
authors.forename: Marieke
authors.initials: M
authors.lastname: De Kam
authors.forename: Frits J
authors.initials: FJ
authors.lastname: Berends
authors.forename: Renee
authors.initials: R
authors.lastname: Wiezer
authors.forename: Bart A
authors.initials: BA
authors.lastname: Van Wagensveld
authors.forename: Dingeman J
authors.initials: DJ
authors.lastname: Swank
authors.forename: Arijan
authors.initials: A
authors.lastname: Luijten
authors.forename: Hanno
authors.initials: H
authors.lastname: Pijl
authors.forename: Jacobus
authors.initials: J
authors.lastname: Burggraaf
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000178:diet therapy / Q000209:etiology / Q000601:surgery; D031204:Caloric Restriction; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000188:drug therapy; D004038:Diet, Reducing; D005260:Female; D015390:Gastric Bypass; D005951:Glucose Tolerance Test; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000178:diet therapy* / Q000601:surgery; D013564:Sympathetic Nervous System / Q000503:physiopathology; D016896:Treatment Outcome; D014630:Vagus Nerve / Q000503:physiopathology; D015431:Weight Loss
chemical_list: D007004:Hypoglycemic Agents