Calcitonin gene-related peptide: A molecular link between obesity and migraine?

Epidemiological studies have begun to suggest obesity is a risk factor for chronic migraine, although no causal relationship has been established and risk factors for progression from episodic to chronic migraine remain unknown. The neuropeptide calcitonin gene-related peptide (CGRP) plays a important role in the pathophysiology of migraine. Here, the potential role of CGRP as a molecular link between obesity and migraine is reviewed. A mechanistic association is supported by several lines of evidence: 1) common markers are elevated in obesity and migraine, 2) adipose tissue secretes proinflammatory cytokines and adipocytokines that have been implicated in migraine pathophysiology and 3) elevated levels of CGRP have been found in plasma of obese individuals. We propose that CGRP released from trigeminal neurons may represent a biological link between obesity and migraine. Enhanced trigeminal CGRP production in obese susceptible individuals may lower the threshold necessary to trigger migraine attacks, leading to more frequent episodes and eventually to chronic migraine.