{'fraction_non_alphanumeric': 0.02120141342756184, 'fraction_numerical': 0.02120141342756184, 'mean_word_length': 5.0588235294117645, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
High nocturnal melatonin in adolescents with chronic fatigue syndrome.

Decreased quality of sleep is frequently reported by chronic fatigue syndrome (CFS) patients. The pineal hormone melatonin is involved in regulation of sleep. We analyzed the nocturnal rise in melatonin in 13 adolescent CFS patients and 15 healthy age-matched controls. Saliva samples were collected at hourly intervals between 1700 and 0200 h. Nocturnal saliva melatonin levels were significantly higher in CFS patients, compared with controls, at midnight, 0100 h, and 0200 h (P < 0.001). No differences were observed in timing of melatonin increase in saliva between patients and controls. Time of sleep onset and duration of sleep did not differ significantly between patients and controls. However, all CFS patients and only one of the controls in our study group reported unrefreshing sleep. Our data demonstrate that sleep problems in adolescents with CFS are associated with increased melatonin levels during the first part of the night. Based on these data, we suggest that there is no indication for melatonin supplementation in adolescents with CFS.