Big headache: auras may add risk to migraines.

As if the headaches weren't enough. Women who experience migraines that are preceded by sensory irregularities face a heightened risk of heart attack, stroke, and other cardiovascular problems, a long-term study of middle-aged women shows.

Some people with migraines have sensory anomalies, called auras, which can include zigzag lines or spots of light in the visual field or grayed vision. Auras can also be characterized by tingling in the limbs and physical weakness.

To investigate potential links among migraines, strokes, and heart problems, the scientists beginning in 1992 identified 3,610 female health professionals who had had migraines during the past year. Of these, 40 percent had experienced auras. The women in the study, who were otherwise healthy and over age 45, were participating in a large trial investigating various medical conditions, says study coauthor Tobias Kurth, a neuroepidemiologist at Harvard Medical School and Brigham and Women's Hospital in Boston.

Over the next 10 years, the women who had experienced migraines with auras had twice as many strokes and heart attacks as did women in the larger trial who had no history of migraines. On the other hand, there was no significant difference in the rate of cardiovascular problems between women with aurafree migraines and the migrainefree women.

Women experiencing auras were also nearly twice as likely to have chest tightness or to need heart surgery, and they were more than twice as likely to die from a cardiovascular problem during the study, the researchers report in the July 19 Journal of the American Medical Association.

"The results are really consistent for all these areas of heart problems" which lends credibility to the study, says Richard B. Lipton, a neurologist at the Albert Einstein College of Medicine in New York City.

The researchers adjusted the data to account for smoking, hormone use, medications, weight, alcohol consumption, exercise, cholesterol, diabetes, blood pressure, menopausal status, and family history of heart disease.

Previous studies had tied migraines to stroke, with some of the strongest evidence connecting stroke risk to migraines with aura in young women. By expanding that finding to women over 45, the new study represents "the best evidence yet" of an overall stroke linkage, Lipton says.

The cause of migraines is unclear, as is the reason for the correlation between auras and cardiovascular problems. Some research suggests that a mild heart abnormality may contribute to the stroke-aura connection by shunting oxygen-poor blood to the brain (SN: 2//19/05, p. 119).

Other evidence has linked increased cardiovascular risk to a variant form of a gene that affects blood concentrations of a compound called homocysteine. A recent study found a stronger association of the variant with migraines with aura than with other migraines.