Migraine chronification as an allostatic disorder: a proof-of-concept study.

ABSTRACT

OBJECTIVE: The underpinning biologics of migraine chronification are not well understood. We aim to investigate the role of the cumulative burden of stress, namely the allostatic load, in migraine chronification. METHODS: This was a cross-sectional study. The allostatic load was measured with a composite multi-system score (BALI Bologna Allostatic Load Index), evaluating 20 biomarkers representing four physiological systems immune, metabolic, cardiovascular, and neuroendocrinological systems. BALI score was subdivided into high score and low score based on the distribution in controls. Migraine patients were included and subclassified into low-frequency episodic migraine group (low-EM group), high-frequency episodic migraine group (high-EM group), and chronic migraine group (CM group). RESULTS: The distribution of BALI high-score increased in parallel with headache attacks monthly frequency 16% in low-EM group (n = 10), 24% in high-EM group (n = 12), and 40% in CM group (n = 21) (p = 0.017). In a multivariable analysis, the odds ratio of having a high-score BALI in CM patients (vs. low-EM patients) was 2.78 (95% CI 1.07-7.22; p = 0.036). Individual BALI biomarkers values which were significantly different among migraine subgroups included systolic blood pressure (p = 0.018), diastolic blood pressure (p < 0.001), and heart rate (p = 0.019). CONCLUSION: Our study substantiates this emerging concept of migraine chronification as an allostatic disorder.