Alzheimer’s disease has proven to be a daunting foe. A cure remains elusive as treatments have come up short, perhaps because most have been based on a faulty hypothesis. The medicines on hand might temporarily ease symptoms—if the patient is lucky. But that’s about it.
File under frustrating.
In fact, you could hear the frustration in Dallas Anderson’s voice in an interview with NPR, when he talked about recent research examining the role of gender in Alzheimer’s. “Sex is such a basic variable, you’d think that we really would have nailed things down by now,” says Anderson, an epidemiologist at the National Institute on Aging. “But no.”
Anderson was reacting to research unveiled in July at the annual Alzheimer’s Association International Conference (AAIC) that shows that the disease progresses differently in women than it does in men. Two thirds of the approximately 5.8 mil-lion Americans living with the disease are women. That’s because women live longer than men, right? Well, that’s long been the assumption, but there’s more to it than that.
For instance, tau—a protein that can destroy nerve cells and that’s associated with Alzheimer’s—spreads differently in women than men. Vanderbilt University researchers looked at 301 people with normal cognitive skills and 161 others with mild impairment. Using PET scans, the re-searchers found that women with mild impairment had tau deposits that were more diffuse and spread out than in men. Researchers “speculate that this may favor an accelerated brain-wide tau spread in women, which may lead to cognitive decline,” according to an AAIC press release.
Meanwhile, researchers with the University of California–San Diego reported findings at the AAIC meeting that show that women metabolize glucose better in regions of the brain affected by Alzheimer’s, giving them more ability to compensate for the brain damage. It also makes the dis-ease more difficult to diagnose with standard clinical exams and memory tests.
Erin Sundermann, a neuropsychologist at UCSD School of Medicine and one of the researchers, told Managed Care in an email that her findings challenge “the likely erroneous as-sumption that Alzheimer’s and its associated brain changes operates in the same way and according to the same temporal pattern in women versus men, and the better we can under-stand these differences, the better we will be able to develop more personalized dementia risk measurements and interventions.”
These could include sex-adjusted norms and cutoffs on clinical tests of memory and cognition. Lower brain glucose metabolism, as determined by a PET scan, might be deemed a risk factor for men in the early stages of Alzheimer’s but not in women, said Sundermann.
At the same meeting, researchers at the University of Miami presented findings that show a gender difference in several genes associated with Alzheimer’s. Brian Kunkle, a genetic epidemiologist and associate scientist at the University of Miami, told Man-aged Care in an email that his findings support the hypothesis that some genetic factors contributing to AD are not identical for men and women.
“Understanding the different genetic landscape and risk profiles for Alzheimer’s disease between men and women provides information critical for precision medicine, helps refine targets for therapy, and improves diagnosis and prediction,” Kunkle wrote.