Circulating CGRP as a diagnostic biomarker in female migraine patients: a single-center case-control study.

BACKGROUND

Migraine constitutes the predominant cause of disability-adjusted life years (DALYs), yet remains diagnostically challenging due to lack of biomarkers. Calcitonin gene-related peptide (CGRP) has been recognized as the pathophysiological cornerstone of migraine. Despite the therapeutic breakthrough of anti-CGRP therapies, their clinical efficacy remains limited. Given higher prevalence, frequency and severity of migraine in women, this study aims to investigate the diagnostic and therapeutic value of plasma CGRP in female migraine patients.

METHODS

This prospective observational study enrolled 184 female migraine patients and 85 healthy controls. CGRP concentrations were quantitatively analyzed using a magnetic particle chemiluminescent immunoassay (MP-CLIA) platform. High- and low-expression subgroups were stratified according to a predefined cutoff value of serum CGRP levels. Additionally, patients who received the CGRP receptor antagonist rimegepant during the acute phase of migraine were analyzed.

RESULTS

Circulating CGRP concentrations were significantly higher in female migraine patients than those in healthy controls. Receiver operating characteristic (ROC) curve analysis determined that 40.00 pg/mL was the optimal cutoff value for subgroup stratification of CGRP levels. Using this threshold, migraine patients were classified into a high-CGRP subgroup (n = 112) and a low-CGRP subgroup (n = 72). A comparative analysis showed that the high-CGRP group had a higher monthly migraine attack frequency (median [interquartile range, IQR]: 4 [2-8] vs. 3 [2-4]; P = 0.013) and a greater prevalence of pericranial tender points (45.5% vs. 29.2%; P = 0.026). Among patients treated with rimegepant, 45.0% achieved pain-free status 2 h after dosing. Multivariate logistic regression identified shorter migraine attack duration as an independent predictor of therapeutic response (OR = 0.96; 95% CI: 0.93-1.00; P = 0.027). Although CGRP concentrations were moderately elevated in the rimegepant responder group, no statistically significant intergroup difference was observed.

CONCLUSIONS

Elevated serum CGRP concentrations exhibited substantial discriminative ability between female migraine patients and healthy controls. Baseline CGRP levels showed some association with rimegepant response, despite no significant statistical difference.

TRIAL REGISTRATION: ChiCTR2500107844 ( www.medicalresearch.org.cn ).