Blood donation and migraine relief: A national population cohort study in Denmark.

INTRODUCTION: Migraine is a prevalent neurological headache disorder. Due to challenges associated with finding effective treatment, many individuals with migraine feel compelled to explore alternative treatment strategies, such as blood donation, hypothesized to provide migraine relief.

METHODS: Through logistic, Poisson, and Cox regression methods, we examined the links between migraine and blood donation activities in two population cohorts: Danish blood donors in the Scandinavian Donations and Transfusions Database (SCANDAT-DK, N >1 million) and the Danish Blood Donor Study (N ~ 100,000).

RESULTS: SCANDAT-DK analyses showed no link between migraine and the propensity to become a blood donor among males (odds ratio [OR]Males  = 0.95 [95% Confidence Interval: 0.86-1.04], and a reduced propensity among females ORFemales  = 0.88 [0.83-0.93]). The incidence of migraine was not reduced upon blood donation (standardized incidence ratio [SIR]Males  = 0.94 [0.83-1.06]; SIRFemales  = 1.04 [0.99-1.10]). Donors with migraine demonstrated longer intervals between donations (hazard ratio [HR]Males  = 0.87 [0.85-0.91], HRFemales  = 0.80 [0.78-0.82]), and an increased risk of donor lapse (ORMales  = 1.23 [1.14-1.32]; ORFemales  = 1.28 [1.22-1.33]). Results were corroborated in DBDS using self-reported migraine. Genetic predisposition to migraine associated with longer intervals in females (HRFemales  = 0.98 [0.97-0.99]), but not in males.

DISCUSSION: Our findings do not support the hypothesis that blood donation serves as a viable treatment strategy among migraine patients. Future prospective investigations may help to elucidate the underlying biological mechanisms by which blood donation may influence migraine pathology.