title: Obstructive sleep apnoea during REM sleep and incident non-dipping of nocturnal blood pressure: a longitudinal analysis of the Wisconsin Sleep Cohort.
abstract: BACKGROUND
  Non-dipping of nocturnal blood pressure (BP) is associated with target organ damage and cardiovascular disease. Obstructive sleep apnoea (OSA) is associated with incident non-dipping. However, the relationship between disordered breathing during rapid eye movement (REM) sleep and the risk of developing non-dipping has not been examined. This study investigates whether OSA during REM sleep is associated with incident non-dipping.
  
  
  METHODS
  Our sample included 269 adults enrolled in the Wisconsin Sleep Cohort Study who completed two or more 24 h ambulatory BP studies over an average of 6.6 years of follow-up. After excluding participants with prevalent non-dipping BP or antihypertensive use at baseline, there were 199 and 215 participants available for longitudinal analysis of systolic and diastolic non-dipping, respectively. OSA in REM and non-REM sleep were defined by apnoea hypopnoea index (AHI) from baseline in-laboratory polysomnograms. Systolic and diastolic non-dipping were defined by systolic and diastolic sleep/wake BP ratios >0.9. Modified Poisson regression models estimated the relative risks for the relationship between REM AHI and incident non-dipping, adjusting for non-REM AHI and other covariates.
  
  
  RESULTS
  There was a dose-response greater risk of developing systolic and diastolic non-dipping BP with greater severity of OSA in REM sleep (p-trend=0.021 for systolic and 0.024 for diastolic non-dipping). Relative to those with REM AHI<1 event/h, those with REM AHI≥15 had higher relative risk of incident systolic non-dipping (2.84, 95% CI 1.10 to 7.29) and incident diastolic non-dipping (4.27, 95% CI 1.20 to 15.13).
  
  
  CONCLUSIONS
  Our findings indicate that in a population-based sample, REM OSA is independently associated with incident non-dipping of BP.
authors: Department of Medicine, Section of Pulmonary and Critical Care, Sleep Disorders Center, University of Chicago, Chicago, Illinois, USA.
authors: Babak
authors: B
authors: Mokhlesi
authors: Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors: Erika W
authors: EW
authors: Hagen
authors: Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors: Laurel A
authors: LA
authors: Finn
authors: Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors: Khin Mae
authors: KM
authors: Hla
authors: Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, USA.
authors: Jason R
authors: JR
authors: Carter
authors: Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors: Paul E
authors: PE
authors: Peppard
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D015995:Prevalence; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology / Q000503:physiopathology*; D012895:Sleep, REM / Q000502:physiology*; D013997:Time Factors; D014922:Wisconsin / Q000453:epidemiology
keywords: Sleep apnoea