title: A multinational study of the relationships between nighttime urinary melatonin production, age, gender, body size, and latitude.
abstract: Overnight urines were collected each month for 12-16 months from 321 normal subjects at 19 medical centers in 14 countries distributed on 5 continents at latitudes from 31 01 South to 77 00 North. Mean melatonin concentration was found to negatively correlate with age, weight, and height. When the sexes were considered separately melatonin only correlated with age for female and with age and weight for males. A weak correlation with latitude, but not longitude, was also found.
authors.affiliation: Psychiatric Research Center University of Tromsø, PFFT at Asgård Hospital, N-9291 Tromsø, Norway.
authors.forename: L
authors.initials: L
authors.lastname: Wetterberg
authors.forename: T
authors.initials: T
authors.lastname: Bratlid
authors.forename: L
authors.initials: L
authors.lastname: von Knorring
authors.forename: G
authors.initials: G
authors.lastname: Eberhard
authors.forename: A
authors.initials: A
authors.lastname: Yuwiler
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001824:Body Constitution; D002940:Circadian Rhythm; D015986:Confounding Factors, Epidemiologic; D005260:Female; D014943:Global Health; D006801:Humans; D008297:Male; D008550:Melatonin / Q000652:urine*; D008875:Middle Aged; D011159:Population Surveillance; D012016:Reference Values; D012737:Sex Factors
chemical_list: D008550:Melatonin