β-Alanine and γ-aminobutyric acid in chronic fatigue syndrome

BackgroundDue to the occurrence of sleep disturbances and fatigue in chronic fatigue syndrome (CFS), an investigation was performed to examine if there is an abnormal excretion of γ-aminobutyric acid (GABA) and/or its structural analogue β-alanine in the urine from CFS patients. Both GABA and β-alanine are inhibitory neurotransmitters in the mammalian central nervous system.MethodsThe 24 h urine excretion of GABA and β-alanine was determined by isotope dilution gas chromatography mass spectrometry in 33 CFS patients and 43 healthy controls. The degree of symptoms in both patients and controls was measured by grading of three typical CFS symptoms using a Visual Analogue Scale.ResultsMen had a significantly higher excretion of both β-alanine and GABA than women. Comparing CFS patients with healthy controls showed no significant difference in excretion of neither β-alanine nor GABA. No correlation was found between the excretion of β-alanine or GABA and any of the three characteristic CFS symptoms measured. However, two female and two male CFS patients excreted considerably higher amounts of β-alanine in their 24 h urine samples than control subjects.ConclusionsIncreased excretion of β-alanine was found in a subgroup of CFS patients, indicating that there may be a link between CFS and β-alanine in some CFS patients.