title: Relationship between self-reported sleep duration and changes in circadian blood pressure.
abstract: BACKGROUND
  Abnormalities in sleep duration and circadian blood pressure (BP) rhythm are both independently associated with increased risk of death and cardiovascular disease. The relationship, however, between these two entities remains unclear. This study was undertaken to determine whether abnormal sleep duration is associated with nondipping status and elevated morning surge.
  
  
  METHODS
  In a cross-sectional study, we assessed the relationship between self-reported sleep duration and circadian BP profiles from 24-h ambulatory BP monitoring (ABPM) in 108 normotensive and 417 hypertensive subjects, independent of relevant sociodemographic, anthropometric, and medical factors.
  
  
  RESULTS
  On average, subjects reported sleeping 6.5 +/- 1.7 h with 18.5% sleeping < or =5 h and 7.6%, > or =9 h. There were 199 (37.9%) nondippers in our cohort and the mean morning surge was 18.7 +/- 1.7 mm Hg. The adjusted odds ratio for nondipping (<10% nocturnal systolic BP fall) associated with a 1-h decrement in sleep duration was 1.12 (P = 0.04) and with age per 5-year increment, 1.15 (P = 0.0003). The adjusted odds ratio for an elevated morning surge (> or =18.0 mm Hg) associated with a 1-h increment in sleep duration was 1.13 (P = 0.02).
  
  
  CONCLUSIONS
  Our study indicates that a sleep deficit is associated with nondipping and a decreased morning surge, whereas a sleep surfeit is associated with less nondipping and an increased morning surge. These findings provide a possible link for the heightened risk of cardiovascular disease associated with disturbances in circadian BP rhythm and the extremes of sleep quantity.
authors.affiliation: Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Oded
authors.initials: O
authors.lastname: Friedman
authors.forename: Yajur
authors.initials: Y
authors.lastname: Shukla
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Logan
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000150:complications; D002940:Circadian Rhythm; D003430:Cross-Sectional Studies; D020920:Dyssomnias / Q000453:epidemiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012650:Self Disclosure; D012890:Sleep; D011795:Surveys and Questionnaires; D013997:Time Factors