title: Cardiac autonomic function and insulin resistance for the development of hypertension: a six-year epidemiological follow-up study.
abstract: OBJECTIVE
  To explore the impact of cardiac autonomic function (CAF) and insulin resistance (IR) on incident hypertension.
  
  
  RESULTS
  In 1996, 1638 subjects finished baseline examination, which included anthropometry, blood pressures, CAF, blood biochemistry, plasma insulin, urine examination and electrocardiogram. CAF included standard deviation of normal-to-normal intervals or RR intervals (SDNN), low- and high-frequency power spectrum (LF and HF), and LF/HF ratio at supine for 5 min, the RR interval changes during lying-to-standing maneuver, and the ratio between the longest RR interval during expiration and the shortest RR interval during inspiration (E/I ratio). We used homeostasis model assessment to define beta cell function (HOMA-B) and insulin resistance (HOMA-IR). In total, 992 non-hypertensive participants completed the follow-up assessment in 2003 and 959 participants were included for the final analysis. Incident hypertension was determined by blood pressure status at follow-up. In unadjusted model, both square root of HOMA-IR (OR:3.37, 95%CI: 2.10-6.64) and HOMA-B (OR:0.996, 95%CI: 0.992-0.999) were related to incident hypertension. In multivariate model, square root of HOMA-IR (OR:1.97, 95%CI: 1.05-3.70), but not HOMA-B, was associated with incident hypertension. After further adjustment for baseline CAF, the positive relationship between the square root of HOMA-IR and incident hypertension disappeared. In contrast, LF/HF ratio (OR:1.18, 95%CI: 1.01-1.37), HF power (OR:0.98, 95%CI: 0.96-0.999), and E/I ratio (OR:0.71, 95%CI: 0.54-0.95) were each independently associated with incident hypertension after further adjustment for HOMA measures.
  
  
  CONCLUSIONS
  Sympathovagal imbalance with an apparently decreased parasympathetic tone is an important predictor of incident hypertension independent of IR.
authors: Department of Family Medicine, College of Medicine, National Cheng Kung University, Taiwan, ROC; Department of Family Medicine, National Cheng Kung University Hospital, Taiwan, ROC.
authors: J S
authors: JS
authors: Wu
authors: Y C
authors: YC
authors: Yang
authors: F H
authors: FH
authors: Lu
authors: T S
authors: TS
authors: Lin
authors: J J
authors: JJ
authors: Chen
authors: Y H
authors: YH
authors: Huang
authors: T L
authors: TL
authors: Yeh
authors: C J
authors: CJ
authors: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry; D001794:Blood Pressure; D016021:Epidemiologic Studies; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D007333:Insulin Resistance; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010275:Parasympathetic Nervous System / Q000378:metabolism / Q000503:physiopathology*; D011795:Surveys and Questionnaires
keywords: 30max/15min ratio; CAF; Cardiac autonomic function; E/I ratio; HF; HOMA-B; HOMA-IR; IR; Incident hypertension; Insulin resistance; LF; SDNN; a ratio between the RR intervals during expiration and inspiration; a ratio between the longest RR interval around the 30th beat and the shortest RR interval around the 15th beat after standing; cardiac autonomic function; high frequency; homeostasis model assessment for insulin resistance; homeostasis model assessment to define beta cell function; insulin resistance; low frequency; standard deviation of normal-to-normal intervals or RR intervals