Serum nitrite and nitrate levels in children with obstructive sleep-disordered breathing

Kaditis, Athanasios; Alexopoulos, Emmanouel; Ntamagka, Georgia; Chaidas, Konstantinos; Karathanasi, Anastasia; Gougoura, Sofia; Papathanasiou, Afroditi A.; Liakos, Panagiotis; Zintzaras, Elias; Gourgoulianis, Konstantinos

doi:10.1016/j.sleep.2009.03.013

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Volume 11, Issue 3 , Pages 258-262, March 2010

Serum nitrite and nitrate levels in children with obstructive sleep-disordered breathing

Athanasios Kaditis
- Sleep Disorders Laboratory, University of Thessaly School of Medicine, Larissa, Greece
- Corresponding author. Tel.: +30 6948530256.
Emmanouel Alexopoulos
- Sleep Disorders Laboratory, University of Thessaly School of Medicine, Larissa, Greece
Georgia Ntamagka
- Sleep Disorders Laboratory, University of Thessaly School of Medicine, Larissa, Greece
Konstantinos Chaidas
- Sleep Disorders Laboratory, University of Thessaly School of Medicine, Larissa, Greece
Anastasia Karathanasi
- Sleep Disorders Laboratory, University of Thessaly School of Medicine, Larissa, Greece
Sofia Gougoura
- Department of Biochemistry, University of Thessaly School of Medicine, Larissa, Greece
Afroditi A. Papathanasiou
- Department of Biomathematics, University of Thessaly School of Medicine, Larissa, Greece
Panagiotis Liakos
- Department of Biochemistry, University of Thessaly School of Medicine, Larissa, Greece
Elias Zintzaras
- Department of Biomathematics, University of Thessaly School of Medicine, Larissa, Greece
- Institute of Clinical Research and Health Policy Studies, Tufts-New England Medical Center, Tufts University School of Medicine, Boston, MA, USA
Konstantinos Gourgoulianis
- Sleep Disorders Laboratory, University of Thessaly School of Medicine, Larissa, Greece

Received 3 February 2009; received in revised form 2 March 2009; accepted 14 March 2009.

Abstract

Background

Diminished nitric oxide (NO) levels have been reported in adults with obstructive sleep apnea but no data are available for children with obstructive sleep-disordered breathing (SDB).

Objectives

To assess levels of serum NO metabolites in children with SDB and to explore the effects of NO metabolites, SDB and their interaction on blood pressure.

Methods

Morning nitrite, the sum of nitrite and nitrate (NO_x), and the average of evening and morning blood pressure were assessed in children with SDB referred for polysomnography and in controls without SDB.

Results

Forty-three children with SDB (age: 5.8±2.1years) had moderate-to-severe nocturnal hypoxemia (SpO₂ nadir: 85.6±4%), 54 subjects (6.6±2.7years) had mild hypoxemia (SpO₂ nadir: 91.4±1.3%) and 20 subjects were controls free of SDB (6.7±3.7years). Subjects with moderate-to-severe hypoxemia had significantly lower ln-transformed NO metabolites (1.4±0.7, nitrites; 2.6±0.5, NO_x) compared to those with mild hypoxemia (1.9±0.8, nitrites; 3±0.6, NO_x) and controls (2.2±0.7, nitrite; 3±0.6, NO_x; p<0.05). The effects of NO metabolites and SDB or their interaction on blood pressure were not significant (p>0.05).

Conclusions

Moderate-to-severe hypoxemia accompanying SDB is associated with reduced concentrations of morning serum NO metabolites, but NO levels do not seem to affect blood pressure.

Keywords: Blood pressure, Nitrate, Nitric oxide, Nitrite, Sleep apnea, Endothelium