Subjective Cognitive Decline in Adults Tied to Modifiable Risks

Adults with subjective cognitive decline — an early indicator of possible Alzheimer’s disease or dementia — were likely to have a large number of modifiable risk factors for dementia, CDC survey data showed.

More than one in three adults ages 45 and older (34.3%) who said they were experiencing worse or more frequent confusion or memory loss had at least four of eight modifiable risk factors for dementia, according to John Omura, MD, of the CDC’s National Center for Chronic Disease Prevention and Health Promotion in Atlanta, and co-authors.

In contrast, only 13.1% of people without subjective cognitive decline had four or more modifiable factors, the researchers reported in the Morbidity and Mortality Weekly Report.

The eight modifiable risk factors included high blood pressure, physical activity, obesity, diabetes, depression, smoking, hearing loss, and binge drinking. Prevalence of subjective cognitive decline jumped from 3.9% in people with no risk factors to 25% in people with four or more (P<0.001).

In 2021, the National Plan to Address Alzheimer’s Disease introduced a new goal that included reducing risk factors to help delay the onset or slow the progression of Alzheimer’s and dementia, Omura and colleagues noted.

“Implementing evidence-based strategies that address modifiable risk factors can help achieve the National Plan’s goal to reduce risk for Alzheimer’s disease and related dementias while promoting healthy aging,” they wrote.

The researchers assessed modifiable risk factors in 140,076 adults 45 and older from 31 states and the District of Columbia using data from the 2019 Behavioral Risk Factor Surveillance System (BRFSS) survey, an annual telephone interview study. Most people taking the survey were 45 to 64 years old (59%); women made up 53% of the sample. About 74% of participants were white, 12% were Black, and 9% were Hispanic.

Survey respondents were classified as experiencing subjective cognitive decline if they responded “yes” when asked whether they had worsening or more frequent confusion or memory loss in the previous 12 months. The overall prevalence of subjective cognitive decline was 11.3%.

High blood pressure (49.9%) and not meeting aerobic physical activity guidelines (49.7%) were the most common risk factors. These were followed by obesity (35.3%), diabetes (18.6%), depression (18%), current cigarette smoking (14.9%), hearing loss (10.5%), and binge drinking (10.3%). Several risk factors were higher in American Indian or Alaska Native, Black, and Hispanic populations than in other races and ethnicities.

People with subjective cognitive decline were more likely overall to have modifiable risk factors. Subjective cognitive decline prevalence ranged from 28.5% in people with depression and 24.7% in people with hearing loss to 11.3% of those who reported binge drinking.

The analysis had limitations, Omura and co-authors noted. Causality between risk factors and subjective cognitive decline cannot be inferred, and not everyone who reports subjective cognitive decline will develop Alzheimer’s disease or dementia. Recall bias and response bias may have influenced survey results. In addition, the findings are from 31 states and the District of Columbia; they may not apply to all parts of the country.