title: Angiotensin receptor blockers regulate the synchronization of circadian rhythms in heart rate and blood pressure.
abstract: OBJECTIVE
  The sympathetic nervous system plays an important role in blood pressure regulation even in the early stages of chronic kidney disease (CKD).
  
  
  METHODS
  To understand the role of the sympathetic system, we examined the relationship between day/night ratios of both heart rate (HR) and mean arterial pressure (MAP) as well as HR variability (HRV, SD) before and during an 8-week treatment with the angiotensin II receptor blocker (ARB), olmesartan, in 45 patients with CKD.
  
  
  RESULTS
  The day/night HR ratio strongly correlated with the day/night MAP ratio before and during ARB treatment. The ratio of [day/night HR ratio] over [day/night MAP ratio] was increased as renal function deteriorated at baseline (r = -0.31, P = 0.04), and it was attenuated (1.10 ± 0.10 to 1.06 ± 0.10; P = 0.04) and became independent of renal function during ARB treatment (r = -0.04, P = 0.8). ARB increased both the day/night HR ratio (1.17 ± 0.09 to 1.21 ± 0.13; P = 0.04) and HRV (10.6 ± 2.9 to 11.7 ± 4.2; P = 0.04), which were lower when baseline renal function deteriorated.
  
  
  CONCLUSIONS
  The present study indicates that there exists a close correlation in circadian rhythms between HR and MAP in CKD. Synchronization between the two rhythms was progressively lost as renal function deteriorated, and ARB partly restored the synchronization. These findings suggest that the sympathetic nervous system is activated as renal function deteriorates, and ARB may suppress its activation.
authors.affiliation: Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, 467–8601 Nagoya, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Sato
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizuno
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Miura
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kato
authors.forename: Shuichi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fuwa
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ogiyama
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Tomonari
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ota
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Shirasawa
authors.forename: Akinori
authors.initials: A
authors.lastname: Ito
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Yoshida
authors.forename: Michio
authors.initials: M
authors.lastname: Fukuda
authors.forename: Genjiro
authors.initials: G
authors.lastname: Kimura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D057911:Angiotensin Receptor Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D002940:Circadian Rhythm / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D057911:Angiotensin Receptor Antagonists