title: Sympathovagal imbalance contributes to prehypertension status and cardiovascular risks attributed by insulin resistance, inflammation, dyslipidemia and oxidative stress in first degree relatives of type 2 diabetics.
abstract: BACKGROUND
  Though cardiovascular (CV) risks are reported in first-degree relatives (FDR) of type 2 diabetics, the pathophysiological mechanisms contributing to these risks are not known. We investigated the association of sympathovagal imbalance (SVI) with CV risks in these subjects.
  
  
  METHODS
  Body mass index (BMI), basal heart rate (BHR), blood pressure (BP), rate-pressure product (RPP), spectral indices of heart rate variability (HRV), autonomic function tests, insulin resistance (HOMA-IR), lipid profile, inflammatory markers, oxidative stress (OS) marker, rennin, thyroid profile and serum electrolytes were measured and analyzed in subjects of study group (FDR of type 2 diabetics, n = 72) and control group (subjects with no family history of diabetes, n = 104).
  
  
  RESULTS
  BMI, BP, BHR, HOMA-IR, lipid profile, inflammatory and OS markers, renin, LF-HF (ratio of low-frequency to high-frequency power of HRV, a sensitive marker of SVI) were significantly increased (p<0.0001) in study group compared to the control group. SVI in study group was due to concomitant sympathetic activation and vagal inhibition. There was significant correlation and independent contribution of markers of insulin resistance, dyslipidemia, inflammation and OS to LF-HF ratio. Multiple-regression analysis demonstrated an independent contribution of LF-HF ratio to prehypertension status (standardized beta 0.415, p<0.001) and bivariate logistic-regression showed significant prediction (OR 2.40, CI 1.128-5.326, p = 0.002) of LF-HF ratio of HRV to increased RPP, the marker of CV risk, in study group.
  
  
  CONCLUSIONS
  SVI in FDR of type 2 diabetics occurs due to sympathetic activation and vagal withdrawal. The SVI contributes to prehypertension status and CV risks caused by insulin resistance, dyslipidemia, inflammation and oxidative stress in FDR of type 2 diabetics.
authors.affiliation: Department of Physiology, Jawaharlal Institute of Post-graduate Medical Education and Research (JIPMER), Puducherry, India.
authors.forename: Gopal Krushna
authors.initials: GK
authors.lastname: Pal
authors.forename: Chandrasekaran
authors.initials: C
authors.lastname: Adithan
authors.forename: Palghat Hariharan
authors.initials: PH
authors.lastname: Ananthanarayanan
authors.forename: Pravati
authors.initials: P
authors.lastname: Pal
authors.forename: Nivedita
authors.initials: N
authors.lastname: Nanda
authors.forename: Thiyagarajan
authors.initials: T
authors.lastname: Durgadevi
authors.forename: Venugopal
authors.initials: V
authors.lastname: Lalitha
authors.forename: Avupati Naga
authors.initials: AN
authors.lastname: Syamsunder
authors.forename: Tarun Kumar
authors.initials: TK
authors.lastname: Dutta
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D050171:Dyslipidemias / Q000150:complications*; D005190:Family; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000150:complications; D007333:Insulin Resistance; D008297:Male; D018384:Oxidative Stress; D058246:Prehypertension / Q000150:complications*; D012044:Regression Analysis; D012306:Risk; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014630:Vagus Nerve / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D015415:Biomarkers