GDF15 and migraine disorder: In contrast, GDF-15 plasma levels were elevated in the migraine group (468.4 pg/mL, 348.3–606.1 pg/mL, n = 226) compared to controls (362.5 pg/mL, 287.0–493.3 pg/mL, n = 96, p < 0.001, Mann–Whitney U test).