title: Melatonin secretion and metabolism in patients with hepatic encephalopathy.
abstract: OBJECTIVE
  The rhythm of melatonin secretion and its blood level changes in cirrhotic patients, but the causes of these alterations have not been sufficiently appreciated. The aim of study was to estimate the dependence between melatonin secretion and metabolism and the severity of hepatic encephalopathy.
  
  
  METHODS
  The study included 75 alcoholic cirrhotic patients (A, B, C) with hepatic insufficiency and 25 healthy subjects (group K). Three groups of patients were identified, 25 patients each, with grade 1, 2, and 3 hepatic encephalopathy according to West-Haven Scale. Immunoenzymatic method was used to measure serum melatonin (at 02:00 h and 09:00 h) level and 6-sulfatoxymelatonin (6-HMS) excretion in the urine (during night and day).
  
  
  RESULTS
  Nocturnal serum melatonin levels (pg/mL) in groups were: K-57.1 ± 11.4, A-38.5 ± 11.2, B-53.4 ± 17.9, C-79.5 ± 27.9 (P < 0.01); whereas diurnal levels were: K-10.9 ± 3.5, A-33.5 ± 12.0, B-53.8 ± 23.1, C-98.5 ± 34.6 (P < 0.01). Similar differences were found in the evaluation of 6-HMS excretion (μg/9 h) in urine at night: group K-23.4 ± 14.4, A-16.6 ± 5.4, B-14.3 ± 6.2 (P < 0.01), C-3.3 ± 1.5 (P < 0.001). Diurnal 6-HMS excretion (μg/15 h) was lower only in group C and it was respectively: K-6.9 ± 3.4, A-7.1 ± 1.7, B-7.6 ± 1.7, C-4.3 ± 2.2 (P < 0.001). Serum ammonia concentrations (μg/dL) were: group K-30.4 ± 8.9, A-51.8 ± 25.4 (P < 0.05), B-73.0 ± 29.8 (P < 0.001), C-107.5 ± 34.8 (P < 0.001). No correlation between melatonin and ammonia levels in all groups was found.
  
  
  CONCLUSIONS
  The elevated melatonin blood levels both at night and day may account for some of the clinical manifestations of hepatic encephalopathy (daytime sleepiness, fatigue).
authors.affiliation: Department of Gastroenterology, Medical University of Lodz, Lodz, Poland.
authors.forename: Cezary
authors.initials: C
authors.lastname: Chojnacki
authors.forename: Patrycja
authors.initials: P
authors.lastname: Wachowska-Kelly
authors.forename: Janusz
authors.initials: J
authors.lastname: Błasiak
authors.forename: Russel J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: Jan
authors.initials: J
authors.lastname: Chojnacki
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000652:urine; D016022:Case-Control Studies; D002940:Circadian Rhythm; D005260:Female; D006501:Hepatic Encephalopathy / Q000097:blood* / Q000209:etiology / Q000503:physiopathology / Q000652:urine; D006801:Humans; D007124:Immunoenzyme Techniques; D016014:Linear Models; D008104:Liver Cirrhosis, Alcoholic / Q000150:complications*; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives / Q000097:blood* / Q000378:metabolism / Q000652:urine; D008875:Middle Aged; D012720:Severity of Illness Index; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; C054513:6-sulfatoxymelatonin; D008550:Melatonin