Changes in plasma glutamate in hemodialysis-related-headache patients: A pilot study

This study aims to determine the profile of glutamate in hemodialysis-related headache (HDH) patients compared to those without HDH.

HDH is a frequent complication in patients undergoing hemodialysis, although little is known about its pathophysiology.

Pilot observational and prospective study. Blood samples of patients consecutively recruited with end-stage renal disease undergoing hemodialysis were obtained at onset, at the first 30min, and at 4h of the hemodialysis session. Glutamate and ALT, AST plasma levels were analyzed at these three stages. Patients were classified into HDH and non-HDH groups. Hospital charts were revised for clinical history and other laboratory results.

Thirty patients (60% males, mean age 70.2±10.5 years) attending the Hemodialysis Unit were included. Nine (30%) experienced HDH. The whole sample showed a significant reduction of glutamate and an increase of ALT and AST along hemodialysis. Specifically, the magnitude of the reduction of plasma glutamate levels concentration in HDH group was stable during the 30min and presented a significant posterior reduction, opposite to the evolution in non-HDH patients.

HDH was associated with a higher variation in plasma glutamate levels with a particular hemodialysis clearance profile, useful to detect patients with a higher susceptibility of developing HDH and receive preventive measures. In conclusion, HDH-group had a later drop in glutamate that could be related to HDH development. Other modalities with more prolonged solute clearance could be considered. We hope the findings of this study will help promote more research to interpret the role of glutamate variations in patients with hemodialysis related headaches.