title: Cardiovagal modulation, oxidative stress, and cardiovascular risk factors in prehypertensive subjects: cross-sectional study.
abstract: BACKGROUND
  Hypertension, one of the modifiable risk factors for cardiovascular disease (CVD), is known to be associated with increased oxidative stress and reduced cardiovagal modulation. Similar to hypertension, prehypertension is associated with increased risk of adverse cardiovascular (CV) events. We planned this study to find the association between prehypertension, cardiovagal modulation, oxidative stress, and associated CV risk factors.
  
  
  METHODS
  We recruited 178 subjects through hypertension screening camps conducted in Puducherry, India. Subjects were grouped into prehypertensive (n = 97) and normotensive (n = 81) groups. They were further subdivided, based on age, as young (20-39 years) and middle-aged (40-60 years) adults. We measured basal physiological parameters, heart rate variability, oxidative stress (thiobarbituric acid reactive substance and total antioxidant capacity (TAC)), and CV risk factors.
  
  
  RESULTS
  We found significant increase in oxidative stress in prehypertensive subjects of both age groups but the cardiovagal modulation decreased significantly in young prehypertensive subjects when compared with normotensive subjects. Correlation of TAC with root mean square of the sum of successive R wave to R wave (RR) interval differences (RMSSD), a cardiovagal modulation parameter (r = 0. 437; P < 0.001), and mean arterial pressure (MAP) (r = -0.318; P < 0.001) was significant even after adjusting for CV risk factors. The correlation between MAP and RMSSD (r = 0.199; P = 0.009) was reduced after adjusting for CV risk factors.
  
  
  CONCLUSIONS
  Prehypertension in young adults is associated with increased oxidative stress and altered cardiovagal modulation. The risk factors for CVDs in prehypertensive young adults were found to be equivalent to that of middle-aged adults who are in the twilight zone for developing CV dysfunctions.
authors: Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India.
authors: Ramkumar
authors: R
authors: Thiyagarajan
authors: Pravati
authors: P
authors: Pal
authors: Gopal Krushna
authors: GK
authors: Pal
authors: Senthil Kumar
authors: SK
authors: Subramanian
authors: Zachariah
authors: Z
authors: Bobby
authors: Ashok Kumar
authors: AK
authors: Das
authors: Madanmohan
authors: M
authors: Trakroo
mesh_terms: D000328:Adult; D001794:Blood Pressure; D002319:Cardiovascular System / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D058246:Prehypertension / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014630:Vagus Nerve / Q000503:physiopathology*; D055815:Young Adult
keywords: blood pressure; cardiovascular risk factors; heart rate variability; hypertension; oxidative stress; prehypertension