Amino Acid Levels in Patients with Fibromyalgia Syndrome

INTRODUCTION Fibromyalgia syndrome (FMS) is a chronic pain syndrome characterised by widespread musculoskeletal pain, fatigue, sleep disturbances, and cognitive symptoms, making the patients seek long-term healthcare. While it is more common in females, the exact aetiopathogenesis of the disease is not clear, and current biomedical and psychosocial treatments are insufficient for many patients. This study aimed to examine the amino acid profile levels of patients with FMS to identify the amino acids that can potentially be used in the diagnosis and treatment of FMS. MATERIALS AND METHODS Ninety participants (female patients diagnosed with FMS: n=45, mean age= 42.80 ± 11.78 years; healthy controls: n=45, mean age=39.60 ±12.35 years) who applied to the Physical Medicine and Rehabilitation Clinic were recruited. Blood samples were drawn from all participants, and their plasma amino acid profiles were measured using an 8045 LC-MS/MS device. Multivariate analysis of the amino acid profile parameters was performed. RESULTS The mean plasma levels of alanine, arginine, aspartic acid, citrulline, glutamine, glutamic acid, glycine, histidine, leucine, isoleucine, alloisoleucine, phenylalanine, proline, serine, tyrosine, valine, alpha aminopimelic acid, hydroxy proline, serotonin, 5-hydroxytryptamine, taurine, glutamine, and glutamic acid were significantly lower in the FMS patients group (p <0.001). In contrast, tryptophan, cystine, anserine, argino succinic acid, and gamma amino butyric acid levels were significantly higher among the patients with FMS (p <0.001). CONCLUSIONS There were obvious differences in the amino acid profiles of patients with FMS and their corresponding healthy controls. These findings indicate the role of amino acids in elucidating the pathophysiology of FMS and as potential biomarkers in its prognosis, treatment, and follow-up.