Ayşe İriz1, Rabia Şemsi2, Burcu Eser3,4, Burak Arslan3,5, Aylin Sepici Dinçel3. 1. Department of Otorhinolaryngology (Ear-Nose-Throat), Gazi University Faculty of Medicine, Ankara, Turkey. 2. Department of Medical Biochemistry, Gazi University Faculty of Medicine, Ankara, Turkey. rabiasemsi2010@gmail.com. 3. Department of Medical Biochemistry, Gazi University Faculty of Medicine, Ankara, Turkey. 4. Gülhane Institute of Health Sciences, R&D Centre, Chromatography Laboratory, The University of Health Sciences, Ankara, Turkey. 5. Department of Medical Biochemistry, Ercis State Hospital, Van, Turkey.
Abstract
PURPOSE: The kynurenine (Kyn) pathway may play a role in certain physiological functions such as behavior, sleep, thermoregulation, and pregnancy. Tryptophan (Trp) is oxidized with tryptophan 2,3-dioxygenase and indolamine 2,3-dioxygenase (IDO). Under normal conditions, hepatic kynurenine is a transcription factor and IDO expression in healthy tissues is very low. The ratio of Kyn to Trp can be used as an indicator to assess IDO activity. This study aimed to determine the relationship between Kyn/Trp ratio and obstructive sleep apnea syndrome (OSAS) disease activity. METHODS: Study participants were categorized in 3 groups: Group 1 included patients with mild OSAS, Group 2, patients with moderate to severe OSAS, and Group 3, individuals considered normal to serve as controls. The demographic characteristics of the patients were recorded. Apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) measurements were performed by diagnostic polysomnography (PSG). Trp and Kyn levels were determined by HPLC-UV method. RESULTS: Group 1 included 30 patients (18 men) with mild OSAS; Group 2 included 42 patients (31 men) with moderate to severe OSAS; and Group 3 included 25 controls (13 men). While there was no statistically significant difference between the levels of tryptophan and kynurenine in the groups, a significant difference was found between the Kyn/Trp ratios. A significant correlation was observed in individuals with a body mass index less than 25 with the Kyn/Trp ratio. In individuals with mild OSAS, a significant correlation was observed between ODI and BMI. In individuals with moderate to severe OSAS, there was a significant correlation between ODI, AHI, and BMI. CONCLUSION: In this study, there was no relationship between OSAS disease severity and IDO activity as assessed by immunoreactivity via the Kyn/Trp pathway.
PURPOSE: The kynurenine (Kyn) pathway may play a role in certain physiological functions such as behavior, sleep, thermoregulation, and pregnancy. Tryptophan (Trp) is oxidized with tryptophan 2,3-dioxygenase and indolamine 2,3-dioxygenase (IDO). Under normal conditions, hepatic kynurenine is a transcription factor and IDO expression in healthy tissues is very low. The ratio of Kyn to Trp can be used as an indicator to assess IDO activity. This study aimed to determine the relationship between Kyn/Trp ratio and obstructive sleep apnea syndrome (OSAS) disease activity. METHODS: Study participants were categorized in 3 groups: Group 1 included patients with mild OSAS, Group 2, patients with moderate to severe OSAS, and Group 3, individuals considered normal to serve as controls. The demographic characteristics of the patients were recorded. Apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) measurements were performed by diagnostic polysomnography (PSG). Trp and Kyn levels were determined by HPLC-UV method. RESULTS: Group 1 included 30 patients (18 men) with mild OSAS; Group 2 included 42 patients (31 men) with moderate to severe OSAS; and Group 3 included 25 controls (13 men). While there was no statistically significant difference between the levels of tryptophan and kynurenine in the groups, a significant difference was found between the Kyn/Trp ratios. A significant correlation was observed in individuals with a body mass index less than 25 with the Kyn/Trp ratio. In individuals with mild OSAS, a significant correlation was observed between ODI and BMI. In individuals with moderate to severe OSAS, there was a significant correlation between ODI, AHI, and BMI. CONCLUSION: In this study, there was no relationship between OSAS disease severity and IDO activity as assessed by immunoreactivity via the Kyn/Trp pathway.
Authors: Abu S M Shamsuzzaman; Mikolaj Winnicki; Paola Lanfranchi; Robert Wolk; Tomas Kara; Valentina Accurso; Virend K Somers Journal: Circulation Date: 2002-05-28 Impact factor: 29.690
Authors: M Pertovaara; A Raitala; T Lehtimäki; P J Karhunen; S S Oja; M Jylhä; A Hervonen; M Hurme Journal: Mech Ageing Dev Date: 2006-02-28 Impact factor: 5.432