Urine levels of catecholamines in Greek children with obstructive sleep‐disordered breathing

Abstract

Introduction Adults with obstructive sleep apnea have increased sympathetic activity. It was hypothesized that in children with symptoms of obstructive sleep‐disordered breathing (SDB), morning urine levels of catecholamines correlate with severity of nocturnal hypoxemia. Methods Children with snoring referred for polysomnography and controls without snoring were recruited. Morning urine norepinephrine, epinephrine, normetanephrine, and metanephrine levels were measured (ng/mg urine creatinine). Results Twelve children (age 5.2 ± 2.3 years) with severe hypoxemia (oxygen saturation of hemoglobin‐SpO₂ nadir ≤86%), 20 subjects (age 6.1 ± 2.1 years) with moderate hypoxemia (SpO₂ nadir ≤90% and >86%), 22 children (age 6.6 ± 1.5 years) with mild nocturnal hypoxemia (SpO₂ nadir >90%), and 10 controls (age 7.1 ± 2.8 years) were studied. Children with severe hypoxemia had significantly higher log‐transformed norepinephrine levels (1.63 ± 0.29) compared to those with moderate hypoxemia (1.43 ± 0.22; P < 0.05) or compared to controls (1.39 ± 0.31; P < 0.05). In subjects with SDB, log‐transformed oxygen desaturation of hemoglobin index or SpO₂ nadir predicted log‐transformed norepinephrine levels after adjustment by age, gender and body mass index (r² = 0.24; and r² = 0.24, respectively; P < 0.01). Conclusions Severity of nocturnal hypoxemia in children with intermittent upper airway obstruction during sleep correlates with morning urine levels of norepinephrine suggesting increased sympathetic tone. Pediatr Pulmonol. 2009; 44:38–45.