The frequency and severity of painful migraine attacks increase as body weight increases, suggest results of a telephone interview study of nearly 3800 migraine sufferers.

Overall, 51.3 percent of interviewees had a normal body mass index (BMI), the ratio of weight to height used to estimate obesity, whereas 30.6 percent were overweight, 10.4 percent were obese and 4.6 percent were morbidly obese. Only 3.1 percent of subjects were underweight.

Sixty-five percent of those interviewed were women and the average age of participants was 38.7 years.

No association was observed between BMI and the prevalence of migraine, Dr. Marcelo E. Bigal, of Albert Einstein College of Medicine, Bronx, New York, and colleagues report in the journal Neurology.

However, as BMI increased, so did the frequency of migraine attacks. The team notes that 4.4 percent of the normal weight group had 10 to 15 headache days per month. This increased to 5.8 percent in the overweight group, 13.6 percent in the obese group and 20.7 percent in the morbidly obese group.

The percentage of subjects who reported severe migraines also increased with BMI group, from 53 percent in subjects of normal weight to 57 percent in the overweight group, 59 percent in the obese group and 65 percent in the morbidly obese group, Bigal and colleagues report.

A similar relationship was observed between BMI and migraine-related disability, light and sound sensitivity, which increased as weight increased.

The next step, investigators note, will be a prospective study to see if weight reduction can improve symptoms in obese migraineurs.

SOURCE: Neurology February 2006.