Objective: We aimed to determine the association between iron deficiency anemia and chronic daily headache.
Methods: This case-control study was conducted in a tertiary care center in Dehradun, India. One hundred patients with chronic daily headache were randomly selected for the study with an equal number of controls. Subsets of chronic daily headache were diagnosed as per the 3rd edition of the International Classification of Headache Disorders. The study participants were assessed for iron deficiency anemia.
Results: The mean age of the patients was 51.1 ± 22.1 years. Male: female ratio was 1:1.08. Chronic migraine was present in 62 (62%), tension-type headache in 23 (23%), and new daily persistent headache in 15 (15%) patients. The majority (96%) of patients had chronic daily headache of mild to moderate severity. Chronic daily headache was of long duration in all patients. Sixty-four (64%) patients had anemia of which 51 (51%) patients had iron deficiency anemia. Iron deficiency anemia showed a significant association with chronic daily headache (p < 0.001), but not with its type, subtype, and duration. Severe iron deficiency anemia had a significant association with the severity of chronic daily headache (p = 0.021). Serum iron, ferritin, total iron-binding capacity, and transferrin saturation also had a significant association with chronic daily headache (p < 0.05 for each), but not with its type, subtype, duration, and severity. Logistic regression analysis showed that iron deficiency anemia, total iron-binding capacity, and transferrin saturation had an independent association with chronic daily headache (p < 0.05 for each).
Conclusions: Iron deficiency anemia had an independent association with chronic daily headache. Severe iron deficiency anemia was related to the severity of chronic daily headache.
Keywords: Iron deficiency anemia; chronic daily headache; chronic migraine; new daily persistent headache; tension-type headache.