title: High bicarbonate levels in narcoleptic children.
abstract: The objective of this study was to evaluate the levels of plasma bicarbonate levels in narcoleptic children. Clinical, electrophysiological data and bicarbonate levels were evaluated retrospectively in children seen in our paediatric national reference centre for hypersomnia. The cohort included 23 control subjects (11.5 ± 4 years, 43% boys) and 51 patients presenting de-novo narcolepsy (N) (12.7 ± 3.7 years, 47% boys). In narcoleptic children, cataplexy was present in 78% and DQB1*0602 was positive in 96%. The control children were less obese (2 versus 47%, P = 0.001). Compared with control subjects, narcoleptic children had higher bicarbonate levels (P = 0.02) as well as higher PCO2 (P < 0.01) and lower venous pH gas (P < 0.01). Bicarbonate levels higher than 27 mmol L(-1) were found in 41.2% of the narcoleptic children and 4.2% of the controls (P = 0.001). Bicarbonate levels were correlated with the Adapted Epworth Sleepiness Scale (P = 0.01). Narcoleptic patients without obesity often had bicarbonate levels higher than 27 mmol L (-1) (55 versus 25%, P = 0.025). No differences were found between children with and without cataplexy. In conclusion, narcoleptic patients had higher bicarbonate plasma levels compared to control children. This result could be a marker of hypoventilation in this pathology, provoking an increase in PCO2 and therefore a respiratory acidosis, compensated by an increase in plasma bicarbonates. This simple screening tool could be useful for prioritizing children for sleep laboratory evaluation in practice.
authors.affiliation: Integrative Physiology of Brain Arousal System, CRNL, INSERM-U1028, University Lyon1, Lyon, France.|National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia and Kleine-Levin Syndrome (CNR narcolepsie-hypersomnie), Lyon, France.|Pediatric Sleep Unit, Hôpital Femme Mère Enfant, University Lyon1, Lyon, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Franco
authors.affiliation: Integrative Physiology of Brain Arousal System, CRNL, INSERM-U1028, University Lyon1, Lyon, France.|National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia and Kleine-Levin Syndrome (CNR narcolepsie-hypersomnie), Lyon, France.|Pediatric Sleep Unit, Hôpital Femme Mère Enfant, University Lyon1, Lyon, France.|Service d'Hormonologie, Groupement Est, Université Lyon 1, Lyon, France.
authors.forename: Aurelie
authors.initials: A
authors.lastname: Junqua
authors.affiliation: Integrative Physiology of Brain Arousal System, CRNL, INSERM-U1028, University Lyon1, Lyon, France.|National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia and Kleine-Levin Syndrome (CNR narcolepsie-hypersomnie), Lyon, France.|Pediatric Sleep Unit, Hôpital Femme Mère Enfant, University Lyon1, Lyon, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Guignard-Perret
authors.affiliation: Integrative Physiology of Brain Arousal System, CRNL, INSERM-U1028, University Lyon1, Lyon, France.|National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia and Kleine-Levin Syndrome (CNR narcolepsie-hypersomnie), Lyon, France.|Pediatric Sleep Unit, Hôpital Femme Mère Enfant, University Lyon1, Lyon, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Raoux
authors.affiliation: Integrative Physiology of Brain Arousal System, CRNL, INSERM-U1028, University Lyon1, Lyon, France.
authors.forename: Magali
authors.initials: M
authors.lastname: Perier
authors.affiliation: Service d'Hormonologie, Groupement Est, Université Lyon 1, Lyon, France.
authors.forename: Veronique
authors.initials: V
authors.lastname: Raverot
authors.affiliation: Service d'Hormonologie, Groupement Est, Université Lyon 1, Lyon, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Claustrat
authors.affiliation: Department of Public Health, Institute of Pharmacy and Service de Biostatistique, University Lyon1, Lyon, France.
authors.forename: Marie-Paule
authors.initials: MP
authors.lastname: Gustin
authors.affiliation: Integrative Physiology of Brain Arousal System, CRNL, INSERM-U1028, University Lyon1, Lyon, France.
authors.forename: Clara Odilia
authors.initials: CO
authors.lastname: Inocente
authors.affiliation: Integrative Physiology of Brain Arousal System, CRNL, INSERM-U1028, University Lyon1, Lyon, France.
authors.forename: Jian-Sheng
authors.initials: JS
authors.lastname: Lin
mesh_terms: D000138:Acidosis / Q000097:blood / Q000150:complications; D000293:Adolescent; D001639:Bicarbonates / Q000097:blood*; D015415:Biomarkers; D016022:Case-Control Studies; D002385:Cataplexy / Q000097:blood / Q000150:complications; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007040:Hypoventilation / Q000097:blood / Q000150:complications; D008297:Male; D009290:Narcolepsy / Q000097:blood* / Q000150:complications; D009765:Obesity / Q000097:blood / Q000150:complications; D012890:Sleep
chemical_list: D001639:Bicarbonates; D015415:Biomarkers
keywords: acid-base balance; excessive daytime sleepiness; gasometry; orexin; respiratory acidosis