Cortisol and migraine. A systematic literature review

Migraine is a highly prevalent and disabling disorder. Because stress appears to be a prominent trigger of this condition and cortisol is a well-established stress hormone, we performed a search on Medline, Scopus, and Web of Science to identify clinical studies that assessed cortisol levels in migraineurs. Four cross-section studies, one observational study, and three both cross-sectional and observational studies were finally included in our analysis. The heterogeneity was modest for the sample size (49.8%) but was remarkably high for a sample matrix (66.0%), thus precluding the possibility to meta-analyze the data. In six of the seven cross-sectional studies, cortisol levels did not differ between the cases and controls. With regard to the four observational trials, both nitroglycerine and human corticotropin-releasing hormone but not m-chlorophenylpiperazine were effective in generating a more prominent cortisol release in migraineurs than in controls. In a fourth observation trial, salivary cortisol did not differ during the migraine attack and during the migraine free-period. In conclusion, even if altered corticotrope responsiveness exists in migraineurs, it appears to be irrelevant in the pathogenesis of migraine.