Researchers say older women with memory complaints may be at greater risk for dementia almost 20 years later.
Study coauthor Alison Kaup, PhD, of the University of California-San Francisco and the San Francisco VA Medical Center, notes that previous studies have suggested memory complaints among older women can be an early sign of Alzheimer's disease or other memory and thinking disorders.
"However," she adds, "our study followed women for longer than most other studies, following these women over the course of nearly 20 years."
The study involved 1,107 women aged 65 and older who were free of dementia at baseline.
The memory problems of each participant were assessed with one question asked several times over an 18-year period: "Do you feel you have more problems with memory than most?" Participants were required to answer with a "yes" or "no."
Memory complaints 'may be early sign of Alzheimer's'
At the start of the study, 89 (8%) of the women complained of memory problems - defined by the researchers as serious enough to be noticed by the women themselves but not serious enough to be highlighted by standard memory tests.
Compared with women who reported no memory problems at study baseline, those who had memory complaints were at 70% greater risk of being diagnosed with a memory and thinking disorder almost 2 decades later.
Women who reported memory problems 10 years prior to study end were 90% more likely to be diagnosed with a cognitive impairment, compared with those who reported no memory problems 10 years previously.
Memory complaints that occurred 4 years before the end of study were linked to a three-times greater risk of a diagnosed cognitive impairment by study end, according to the results.
The researchers say their findings provide further evidence that memory complaints in older adults should receive close attention, as they could be an early indicator of more severe memory and thinking problems later in life.
"SMCs [subjective memory complaints] among cognitively normal older women appear to be an early indicator of risk of cognitive impairment and may be a subtle signal of an underlying neurodegenerative disease process such as AD [Alzheimer's disease] that is still in its earliest stages.
Our results suggest that dementia prevention research trials should target older women with SMCs as a high-risk group, in order to attempt to intervene among those who may be showing the earliest symptoms of neurodegeneration."
The researchers admit there are some limitations to their study. For example, they only included European-American women, meaning their results may not be applicable to men or individuals of other racial or ethnic groups.
What is more, the team notes that because they only assessed study participants for clinical diagnosis of cognitive impairment at one time point - the study end - they cannot be certain as to when they first met the criteria for such a diagnosis.
Earlier this month, Medical News Today reported on a study suggesting that people with larger brain size may be at lower risk for cognitive impairment.