Alzheimer’s: Sex Matters, But So Does Age

A new meta-analysis corrects previous knowledge on sex-specific risk of developing Alzheimer’s disease. After analyzing data from almost 58,000 individuals of both sexes, the researchers suggest that women are more at risk than men during a crucial 10-year span: between ages 65 and 75.

According to an influential study published in JAMA journal 20 years ago, one gene variation of the apolipoprotein E (APOE) gene, E4, placed women at a great risk of developing Alzheimer’s disease (AD) than men. This belief has influenced the way in which specialists understood AD risk factors until now, Medical Xpress reported.

A new meta-analysis that re-evaluates data and evidence suggests that things may not be as clear-cut as it has been thought so far.

The study - conducted by Doctor Scott C. Neu from the Keck School of Medicine at the University of Southern California in Los Angeles, CA, alongside a team of specialists from many institutions - suggests that women and men carrying the E4 variation of the APOE gene are at a similar risk of developing AD.

However, there is one important exception to that rule: women are significantly more susceptible to AD between the ages of 65 and 75, which had not been known until now.

The researchers’ findings were recently published in JAMA Neurology.

The team of researchers analyzed 27 independent research studies, collecting data from 57,979 individuals from North America and Europe. The complex data were provided by the Global Alzheimer’s Association Interactive Network (GAAIN).

After analyzing the data available to them, the researchers concluded that there was no “difference in risk of Alzheimer’s disease across the lifespan of 55 to 85 years” between men and women carrying a copy of the E4 variant of the APOE gene. Yet “women were at increased risk [compared to] men between ages 65 and 75.”

The current findings show that the critical period when women are most at risk is 10 years after the normal start of menopause.

Doctor Judy Pa, another co-author of the study says that women should not rely on genetic testing to learn whether or not they will develop AD. Exhibiting one or more risk factors, she explains, does not necessarily mean that an individual will develop the disease.

“There is controversy in terms of whether people should know their APOE status because it is just a risk factor,” she says. “It doesn’t mean you’re going to get Alzheimer’s disease. Even if you carry two copies of [the gene variant], your chances are greatly increased, but you could still live a long life and never have symptoms.”

According to Pa, women who are at an increased risk of AD may be able to keep its development in check by leading an active life and exercising their cognition.

“Get more exercise. Work out your mind, especially in old age. Pick up hobbies that are cognitively or physically challenging. Reduce processed sugar intake because it’s linked to obesity, which is associated with many chronic diseases,” she says.