title: Heart rate variability and Omega-3 Index in euthymic patients with bipolar disorders.
abstract: BACKGROUND
  Affective disorders are associated with an increased risk of cardiovascular disease, which, at least partly, appears to be independent of psychopharmacological treatments used to manage these disorders. Reduced heart rate variability (SDNN) and a low Omega-3 Index have been shown to be associated with increased risk for death after myocardial infarction. Therefore, we set out to investigate heart rate variability and the Omega-3 Index in euthymic patients with bipolar disorders.
  
  
  METHODS
  We assessed heart rate variability (SDNN) and the Omega-3 Index in 90 euthymic, mostly medicated patients with bipolar disorders (Bipolar-I, Bipolar-II) on stable psychotropic medication, free of significant medical comorbidity and in 62 healthy controls. Heart rate variability was measured from electrocardiography under a standardized 30 minutes resting state condition. Age, sex, BMI, smoking, alcohol consumption and caffeine consumption as potential confounders were also assessed.
  
  
  RESULTS
  Heart rate variability (SDNN) was significantly lower in patients with bipolar disorders compared to healthy controls (35.4 msec versus 60.7 msec; P<0.0001), whereas the Omega-3 Index did not differ significantly between the groups (5.2% versus 5.3%). In a linear regression model, only group membership (patients with bipolar disorders versus healthy controls) and age significantly predicted heart rate variability (SDNN).
  
  
  CONCLUSIONS
  Heart rate variability (SDNN) may provide a useful tool to study the impact of interventions aimed at reducing the increased risk of cardiovascular disease in euthymic patients with bipolar disorders. The difference in SDNN between cases and controls cannot be explained by a difference in the Omega-3 Index.
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany; Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Voggt
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany; Klinik für Psychiatrie und Psychotherapie, Clienia Schlössli, Oetwil am See, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Berger
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany; GKM Gesellschaft für Therapieforschung mbH, Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Obermeier
authors.affiliation: Department of Internal Medicine, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Löw
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany; Klinik für Psychiatrie, Psychotherapie und Psychosomatik, kbo-Lech-Mangfall-Klinik Garmisch-Partenkirchen, Garmisch-Partenkirchen, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Seemueller
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany; Vinzenz-von-Paul-Hospital, Rottweil, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Riedel
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: H J
authors.initials: HJ
authors.lastname: Moeller
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany; Klinik für Psychiatrie, Psychotherapie und Psychosomatik, kbo-Lech-Mangfall-Klinik Garmisch-Partenkirchen, Garmisch-Partenkirchen, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Zimmermann
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany; Dr. von Haunersches Kinderspital, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Kirchberg
authors.affiliation: Department of Preventive Cardiology, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Von Schacky
authors.affiliation: Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany; Department of Psychiatry and Psychotherapy, University Hospital Carl Gustav Carus, TU Dresden, Germany. Electronic address: emanuel.severus@uniklinikum-dresden.de.
authors.forename: E
authors.initials: E
authors.lastname: Severus
mesh_terms: D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000097:blood / Q000503:physiopathology*; D004562:Electrocardiography; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D015525:Fatty Acids, Omega-3
keywords: Bipolar disorder; Cardiovascular disease; Heart rate variability; Omega-3 Index