High bicarbonate levels in narcoleptic children.

Area of Science:

• Pediatric Neurology
• Sleep Medicine
• Respiratory Physiology

Background:

• Narcolepsy is a chronic neurological disorder affecting sleep-wake regulation.
• Understanding associated physiological markers in pediatric narcolepsy is crucial for diagnosis and management.
• Previous research has not extensively explored plasma bicarbonate levels in children with narcolepsy.

Purpose of the Study:

• To investigate and compare plasma bicarbonate levels in children diagnosed with narcolepsy versus healthy controls.
• To explore the potential correlation between bicarbonate levels and narcolepsy symptoms or related conditions like obesity.
• To assess the utility of plasma bicarbonate levels as a potential biomarker for hypoventilation in pediatric narcolepsy.

Main Methods:

• Retrospective analysis of clinical and electrophysiological data from a pediatric reference center.
• Inclusion of 51 de-novo narcolepsy patients and 23 age- and sex-matched control subjects.
• Measurement and comparison of plasma bicarbonate, PCO2, and venous pH, alongside assessment of obesity and cataplexy prevalence.

Main Results:

• Narcoleptic children exhibited significantly higher plasma bicarbonate (P=0.02) and PCO2 (P<0.01), with lower venous pH (P<0.01) compared to controls.
• Elevated bicarbonate levels (>27 mmol L⁻¹) were observed in 41.2% of narcoleptic children versus 4.2% of controls (P=0.001).
• Higher bicarbonate levels correlated with increased sleepiness scores and were more prevalent in non-obese narcoleptic children.

Conclusions:

• Pediatric narcolepsy patients demonstrate elevated plasma bicarbonate levels compared to healthy children.
• These findings suggest potential hypoventilation contributing to respiratory acidosis, compensated by increased bicarbonate.
• Plasma bicarbonate may serve as a simple, valuable screening tool for identifying children who may benefit from sleep laboratory evaluation.