Arterial hypertension in the chronic evolution of migraine: bystander or risk factor? An overview

Background Several risk factors are associated with the chronic evolution of migraine. Clinical and preclinical studies have provided data about the role of hypertension (HT) as one of the potential modifiable risk factors of chronic migraine (CM). This review is focused on the biological and clinical evidence supporting common mechanisms underlying HT and migraine and the potential role of HT in the transition from episodic to chronic migraine. Methods We conducted a narrative review from a literature search covering the available evidence from studies investigating: i) the role of HT in the transition to CM in clinical practice; ii) the biological mechanisms potentially underpinning the association between HT and evolution to CM; iii) the role of antihypertensive medications in migraine prophylaxis. Results HT proved to be at the base of multiple mechanisms underlying migraine and migraine chronicization. Endothelial dysfunction, blood–brain barrier alterations, calcitonin gene-related peptide signaling, and renin–angiotensin–aldosterone system dysregulation are involved in the worsening effect of HT on migraine frequency, and the role of HT in the transition to CM is supported by clinical observations. Conclusions The observed evidence supports HT contribution to CM evolution due to shared pathophysiologic mechanisms. While a bidirectional influence appears to be ascertained, data are still lacking about the one-way role of HT as direct risk factor for CM transition. Further research is needed to confirm a causal role of HT in this process.