Table 1.

Relevant biochemical biomarkers in migraine, obesity, and diabetes mellitus (DM).

Biochemical biomarker	Migraine	Obesity	DM	References
Pro-inflammatory
C-reactive protein	Increased both in migraine with and without aura	Increased	Increased in both type 1 and type 2 DM	(29, 30, 33, 34)
IL-1β	Higher levels during migraine attacks, both in migraine with and without aura	Increased in morbidly obese patients	Higher levels in both type 1 and type 2 DM	(27, 31, 35, 36)
IL-6	No differences in patients outside and during migraine attacks	Increased	Elevated in both poorly and controlled DM	(27, 30, 33)
IL-8	Increased interictal levels in migraine patients	Increased levels and BIM-related	Elevated older patients with DM	(28, 30, 32)
TNF-α	Higher levels during migraine attacks, in both migraine with and without aura	Higher concentrations	Elevated levels	(27, 30, 33)
Neuropeptides
CGRP	Higher levels both in migraine with and without aura	Higher levels	Decreased in type 2 DM	(18, 19, 21, 24)
Substance P	Higher levels both in migraine with and without aura	Higher levels in obese patients	Decreased in type 2 DM	(19, 22, 24)
Neuropeptide Y	Tended to increase during migraine attacks in migraine with aura	Increased	Increased in type 2 DM	(20, 25, 26)
Adipokines
Leptin	Higher levels in migraine with aura	Higher concentrations	Increased in type 2 DM	(37–39)
Adiponectin	Increased levels in both episodic and chronic migraine	Decreased levels	Decreased in type 2 but increased in type 1 DM	(37, 40–43)