Sleep complaints highlight Alzheimer's risk in genetically predisposed women

Sleep complaints may be an important Alzheimer's disease risk factor in older women with a higher genetic predisposition to the disease, according to a new study from researchers at the University of California San Diego. The findings suggest that women with a higher genetic risk for Alzheimer's who reported poorer sleep also showed greater memory difficulties and more Alzheimer's-related brain changes.

Researchers examined 69 women aged 65 years and older participating in the Women Inflammation Tau Study, an ongoing project focused on aging and Alzheimer's disease risk. Participants completed questionnaires about their sleep quality, underwent memory testing and received brain scans that measured tau, a protein that accumulates abnormally in Alzheimer's disease.

The study found that poorer self-reported sleep was associated with worse visual memory performance and greater tau accumulation in brain regions affected early in Alzheimer's disease - but only among women with higher genetic risk. Women with lower genetic risk did not show the same relationship between sleep complaints, memory and tau buildup. The finding was specific to visual memory and was not observed for verbal memory.

Researchers say the results add to growing evidence that sleep disturbances and Alzheimer's disease may reinforce one another over time. Previous studies have suggested that disrupted sleep can contribute to the buildup of abnormal tau proteins, while Alzheimer's-related brain changes may also interfere with healthy sleep patterns. Because women account for nearly two-thirds of Alzheimer's cases and frequently report poorer sleep quality than men, the researchers say sleep may represent an important and potentially modifiable risk factor in older women.