On 16 July, the Alzheimer’s Association launched a press release on a series of findings focussed on the sex-differences in AD that were presented during its conference. As part of the conference presentations, researchers from the United Kingdom reported on the preliminary findings from an analysis aimed to better understand how women’s work-family demands (paid labour force participation, marriage, motherhood) may play a role in late-life memory decline. The study encompassed 6.386 women born between 1935 and 1956. It included reports of waged employment, martial and parenthood status but also results on memory performance tests that were conducted every 2 years after the participants were older than 50.
The team found that women who participated in the paid labour force between early adulthood and middle age (including mothers and non-mothers), experienced slower memory decline in late-life. They further reported that the rate of memory decline was fastest among women who did not engage in waged employment. Another study team looked at levels of amyloid (a biomarker for AD) from 1.022 participants and analysed how well their brains metabolized glucose in regions affected by AD. In addition to this, they also evaluated their performance in verbal memory tests.
The teams’ results supported previous evidence that women outperform men in verbal memory tests when their brains show a minimal to moderate amyloid plaque deposition. However, the scientists reported that there was no difference when comparing men and women with severe amyloid deposition. The researchers also announced that they found higher levels of brain glucose metabolism in women than in men when they compared the groups who had minimal to moderate levels of amyloid. These finding led the team to the conclusion that women may better compensate early-stage AD-related brain changes than men, which in turn may contribute to women’s better verbal memory performance.
Another team drew on data from 5.522 participants to find new sex-specific genetic associations with AD and reported on 11 genes that may be relevant to the development of AD, some of which are only related to men (MCOLN3 and CHMP2B) and some of which only to females (CD1E and PTPRC).
Apart from the differences in genes, biomarkers – in this case tau - for AD may also spread differently through the brains of men and women. To learn more about these potential differences, another team of researchers involved 201 healthy participants and 161 participants with mild cognitive impairment, who received brain scans. The scientists reported that the overall tau network looked very different for men and women when they presented mild cognitive impairment. They found that healthy women had several key brain regions that served as “hubs”, connecting different brain areas within the network. These included parahippocampus, superior parietal, insular, superior temporal. This finding led them to the speculation that the connectivity may favour an increased brain-wide tau spread in women that could in turn lead to faster cognitive decline.
https://www.alz.org/aaic/releases_2019/tuesSexDifferences-jul16.asp
