• Posted May 16, 2024

Brain Decline, Dementia Common Among Older American Indians

Higher rates of blood vessel-damaging conditions like hypertension or diabetes may be driving up rates of cognitive decline and dementia among older American Indians, new research shows.

The study found that 54% of American Indians ages 72 to 95 had some form of impairment in their thinking and/or memory skills, while 10% had dementia.

The underlying causes: Vascular (blood vessel) damage and Alzheimer's disease, in equal measure and sometimes overlapping.

"These results underscore that cognitive impairment among elder American Indians is highly prevalent, more than previously thought,"said Dr. Amy Kelley, deputy director of the U.S. National Institute on Aging (NIA), which funded the study.

"Considering how these new prevalence figures for American Indians are much higher than other groups... it is imperative that we address health disparities to help us find solutions," she said in an NIA news release.

The findings were based on data from nearly 400 participants in the ongoing Strong Heart Study, which has tracked the health of American Indian tribes in three U.S. geographic regions -- the Northern Plains, Southern Plains and South -- for over 30 years.

The data showed that, among 216 participants now aged 72 to 95, about 35% had what's known as mild cognitive impairment (MCI), often a precursor to dementia. That's significantly higher than the level of MCI observed in similarly aged whites (12% to 21%), Black Americans (22% to 25%) or Hispanics (20% to 28%).

Only 45.6% of the older cohort of Strong Heart Study participants had no form of thinking impairment or dementia, the researchers said.

However, because vascular damage tied to diabetes or high blood pressure was often an underlying cause of the brain decline, that offers the American Indian community some hope that health outcomes can improve.

"Vascular risk factors, such as hypertension and diabetes, are known to be modifiable and therefore could be prioritized to potentially reduce the risk of cognitive impairment among American Indians,"said Dallas Anderson, an NIA program director and neuroepidemiologist.

The study was led by Astrid Suchy-Dicey, an epidemiologist researcher at Washington State University in Seattle, and it was published May 15 in the journal Alzheimer's & Dementia.

More information

Find out more about mild cognitive impairment at the Alzheimer's Association.

SOURCE: National Institute on Aging, news release, May 15, 2024