title: [Circadian rhythm of melatonin and blood pressure changes in patients with essential hypertension].
abstract: OBJECTIVE
  To observe the association between melatonin (MLT) secretion and blood pressure changes during 24 hours in hypertensive patients (HPT) with (dipping) or without (non-dipping) night time blood pressure reduction.
  
  
  METHODS
  The 24-hour blood pressure and urine 6-SMT (6-sulfatoxymelatonin, metabolism product of MLT in urine) in the daytime and nighttime were measured in normal control subjects (n = 20), non-dipping HPT group (n = 32) and dipping HPT group (n = 36).
  
  
  RESULTS
  As expected, blood pressure reduction during the night was significantly lower in non-dipping HPT group compared to control and dipping HPT groups. Nighttime 6-SMT was significantly higher than daytime 6-SMT in all groups and nighttime urine 6-SMT levels and ratio of nighttime/daytime urine 6-SMT levels were significantly lower in non-dipping HPT group compared to control and dipping HPT groups (all P < 0.01). Moreover, ratio of nighttime/daytime urine 6-SMT levels are positively correlated blood pressure reduction during nighttime (P < 0.05) in all groups.
  
  
  CONCLUSIONS
  Circadian rhythm of MLT secretion is maintained but nighttime MLT secretion was significantly reduced and related to disorders of circadian rhythm of blood pressure in non-dipping HPT group.
authors.affiliation: Department of Emergency, Hospital of Weifang Medical University, Weifang 261031, China. cuihongwei62@126.com
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Cui
authors.forename: Zhong-Xia
authors.initials: ZX
authors.lastname: Zhang
authors.forename: Ming-Tong
authors.initials: MT
authors.lastname: Gao
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Ai-Hua
authors.initials: AH
authors.lastname: Su
authors.forename: Mei-Ying
authors.initials: MY
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D016022:Case-Control Studies; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology / Q000652:urine*; D008297:Male; D008550:Melatonin / Q000652:urine*; D008875:Middle Aged
chemical_list: D008550:Melatonin