Ventricular cerebrospinal fluid hypocretin-I inversely correlates with glucose levels in cerebrospinal fluid and serum from patients with neurological injuries

Introduction: Hypocretin-1 is a hypothalamic neuropeptide that may help regulate arousal and feeding behavior and is quantifiable in cerebrospinal fluid (CSF). In this retrospective pilot study, hypocretin-1 levels obtained from ventricular CSF of neurologically injured patients were correlated with clinical and laboratory results to test whether arousal or metabolic factors might be related to the level of hypocretin-1. Methods: CSF samples from a heterogeneous group of neurosurgical patients with externally draining intraventricular catheters were assayed in a standard manner for hypocretin-1 and other routine laboratories. Associations were sought between hypocretin-1 and clinical data such as body mass index (BMI), temperature, and Glasgow Coma Scale (GCS) score and between hypocretin-1 and laboratory data such as serum and CSF glucose, protein, and cell counts. Results: Lower levels of ventricular CSF hypocretin-1 were correlated with higher levels of serum (p = 0.020) and ventricular CSF glucose (p = 0.001). Clinical findings such as BMI, temperature, and GCS failed to correlate with hypocretin-1. Conclusions: In a group of neurologically injured patients, hypocretin-1 and glucose levels are inversely correlated. More studies are needed to investigate these associations, particularly in a homogenous patient sample.