“Histamine is one of the key mediators in the development of migraine,” explained lead author Joan Izquierdo Casas, MD, Hospital General de Catalunya, Barcelona, Spain, speaking here on September 22. Excess of plasmatic histamine may be due to diminution of degradation capacity. Alterations of DAO, which is one of the enzymes involved in the degradation of histamine, may cause symptoms in the case of excessive histamine intake.
Dr. Izquierdo and colleagues conducted the double-blind, randomised MIGRADAO 002 study to assess the efficacy of preventive supplementation with DAO in patients with episodic migraine.
The DAO activity of 137 patients with episodic migraine was assessed prior to the study. Patients were included when their DAO activity was considered low (<80 Histamine Degradation Units [HDU]/mL).
“There is a high prevalence of DAO deficiency in migraine,” Dr. Izquierdo reported. Reduced enzyme activity was found in 119 of the 137 patients.
Forty-nine patients received placebo, while 50 were treated with a supplement containing a DAO extract at a dose of 4.2 mg.
“This supplement is considered a dietetic food with special medical uses,” Dr. Izquierdo said. The patients ingested 2 capsules 30 minutes before breakfast, lunch, and dinner for the duration of 1 month.
The number of crises decreased between the randomisation and the final visit in both groups. While this difference was greater with the DAO supplementation (mean, -2.1 vs -1.8 with DAO and placebo, respectively), it did not reach statistical significance.
The average duration of the crises, however, was significantly shorter in the DAO treatment group than in the placebo group, Dr. Izquierda emphasised, with a mean, 5.1 vs 6.3 hours with DAO and placebo, respectively (P< .03).
No significant differences resulted regarding the average intensity of the crises, according to the patient ratings. The use of triptans, however, decreased significantly in the DAO-treated group compared with the placebo group, indicating lower pain intensity (P< .022).
“No adverse events were identified in either group,” Dr. Izquierdo added. With the exception of 2 patients, the whole cohort completed the trial.