Certain diseases may need diagnoses and treatments tailored to gender as a recent study has found that the male and female brains react differently during cardiovascular activity.
A region of the brain that helps to manage body functions including stress, heart rate and blood pressure reacts differently between men and women when presented with certain stimuli, according to the study from the UCLA School of Nursing. The findings suggest that cardiovascular diseases also may manifest differently in women and men, which ultimately could affect how they should be diagnosed and treated. In the study, led by Paul Macey, functional MRI or fMRI, scans were done on volunteers while they performed hand-grip exercises, which raise blood pressure and heart rate through signals from the brain.
Used primarily in research, an fMRI uses magnetic resonance imaging technology to measure brain activity by detecting changes in the blood flow. The researchers found that the portion of a brain region called the insular cortex (which is made up of gyri, or folds) showed differences in activity between men and women. In women, the right side of the front insular gyrus was activated by the hand-grip exercise more than men, who instead had a greater left-side activation of the same region. Women showed a higher resting heart rate than did males, but didn't have as great a heart rate increase when challenged with the hand-grip exercise.
In general, the right side of the insular cortex is more sympathetic, and the left side more parasympathetic. "With the hand grip, the differences were in the left side of the brain, while in the Valsalva study, the differences appeared on the right side, which was a surprise at first," Macey said. "What both studies show, however, is that healthy men's and women's brains respond differently, so we may have to re-evaluate separately in men and women what constitutes a disease state versus a healthy state to see if people are more or less vulnerable to cardiovascular illness according to their sex." The research also sheds more light on the functions of the insular gyri. This middle area of the brain had been difficult to test until recently through imaging techniques, Macey said. The study is published in the journal Biology of Sex Differences.