NMR metabolic profiling of serum identifies amino acid disturbances in chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is a debilitating multisystem disorder characterised by long-term fatigue with a variety of other symptoms including cognitive dysfunction, unrefreshing sleep, muscle pain, and post-exertional malaise. It is a poorly understood condition that occurs in similar to 5 in every 1000 individuals. We present here a preliminary study on the analysis of blood samples from 11 CFS and 10 control subjects through NMR metabolic profiling. Identified metabolites that were found to be significantly altered between the groups were subjected to correlation analysis to potentially elucidate disturbed metabolic pathways. Our results showed a significant reduction of glutamine (P = 0.002) and ornithine (P<0.05) in the blood of the CFS samples. Correlation analysis of glutamine and ornithine with other metabolites in the CFS sera showed relationships with glucogenic amino acids and metabolites that participate in the urea cycle. This indicates a possible disturbance to amino acid and nitrogen metabolism. It would be beneficial to identify any potential biomarkers of CFS for accurate diagnosis of the disorder. (C) 2012 Elsevier B.V. All rights reserved.