Plasma level of calcitonin gene-related peptide in the diagnosis of episodic migraine with comorbid conditions

Comorbid and co-occurring diseases are risk factors for the progression of episodic migraine to chronic migraine. Biomarkers for migraine could help with diagnosis and treatment selection and monitoring. Aim. To examine the role of the plasma level of calcitonin-gene-related peptide (CGRP) in the diagnosis of episodic migraine in combination with comorbid conditions in the form of cervicalgia and psychoemotional disorders. Materials and methods. The study included 112 patients (84 women, 28 men; mean age 18-58 years), episodic migraine with typical aura – 17, without aura – 60. Patients were divided into 3 groups: I – episodic migraine with cervicalgia (n = 42), II – episodic migraine only (n = 35), III – cervicalgia only (n = 35). The Visual Analogue Scale, Migraine Disability Assessment (MIDAS) score, Headache Impact Test (HIT-6), Neck Disability Index, State-Trait Anxiety Inventory, Beck’s Depression Inventory and the number of days with headache were assessed. The control group consisted of 30 healthy persons to compare the level of CGRP. The serum level of CGRP was determine by enzyme-linked immunosorbent assay using the sandwich ELISA principle. Results. Plasma level of CGRP was higher in groups I and II compared with group III (P = 0.012543), where it did not differ from the control (51.48 ± 5.08 pg/ml). The highest level of CGRP was observed in group I (242.98 ± 5.08 pg/ml) in comparison with group II (145.82 ± 15.38 pg/ml, P = 0.000341). Co-occurring neck-pain in patients with episodic migraine was associated with mood and anxiety disorders. Migraine severity, according to the MIDAS score, was most significantly influenced by plasma level of CGRP, severity of subjective and objective symptoms of headache by the HIT-6, level of State-anxiety and Trait-anxiety, number of days with headache during the last 3 months. Conclusions. The serum level of CGRP is a reliable diagnostic and differential diagnostic laboratory biomarker for episodic migraine. Additional painful syndrome such as cervicalgia influences CGRP level and daily activity, mood and anxiety disorders in episodic migraine patients.