title: Association between circadian rhythm of blood pressure and glucose tolerance status in normotensive, non-diabetic subjects.
abstract: OBJECTIVE
  To examine whether circadian rhythm of blood pressure (BP) is associated with glucose tolerance status in normotensive, non-diabetic subjects.
  
  
  METHODS
  A cross-sectional study recruited normotensive and non-diabetic subjects, aged 35-79 years. A 75 g oral glucose tolerance test (OGTT) and 24-h ambulatory blood pressure monitoring (24-h ABPM) were performed.
  
  
  RESULTS
  Among 31 impaired glucose tolerance (IGT) and 36 normal glucose tolerance (NGT) study subjects, the mean (+/-S.D.) diurnal-nocturnal differences of average systolic BP (SBP) were 7.1+/-6.9 and 9.9+/-6.2 mmHg, respectively (p=0.086). In a linear mixed-effects regression model, however, taking each measurement of BP as the outcome, nighttime reduction of SBP in the IGT group was 7.19 mmHg, which was significantly smaller compared to a reduction of 9.80 mmHg in the NGT group (p-value for IGT: nighttime interaction=0.0014). The prevalence of non-dipping BP pattern was 77.4% in the IGT group which was significantly higher than 52.8% of the NGT group (p=0.036). Logistic regression revealed a significant effect of IGT for predicting non-dipping pattern with an adjusted odds ratio of 3.71 (95% CI: 1.09, 12.66, p=0.029).
  
  
  CONCLUSIONS
  Among normotensive, non-diabetic subjects, the decreased nocturnal BP reduction was associated with impaired glucose tolerance status.
authors.affiliation: Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand. linali2006@gmail.com
authors.forename: Lina
authors.initials: L
authors.lastname: Li
authors.forename: Supamai
authors.initials: S
authors.lastname: Soonthornpun
authors.forename: Virasakdi
authors.initials: V
authors.lastname: Chongsuvivatwong
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm / Q000502:physiology*; D003430:Cross-Sectional Studies; D018149:Glucose Intolerance / Q000503:physiopathology*; D005951:Glucose Tolerance Test; D006801:Humans; D008875:Middle Aged; D016017:Odds Ratio