Research shows that some ethnic and racial groups might have different biomarkers for Alzheimer's disease and related dementias.

A new study of Latinos of Mexican descent in the journal Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring offers a possible diagnostic tool for the country's fastest growing demographic group.

"This is a huge issue, because right now the field is working towards identifying better cutoff values to know when further action is needed. And so, if we don't have a diverse sample, that might lead to further propagating health disparities, with some people perhaps being missed or over-diagnosed," said lead author Mitzi Gonzales of the University of Texas Health Science Center at San Antonio.

The current process of diagnosing cognitive disorders involves numerous cumbersome exams, labs and scans, and doctors lack an easy way to confirm their diagnosis.

"So there's a big effort in the field to try to find simpler, non-invasive, less expensive approaches to improve either diagnosis, or at least stratification, of who might be at risk of converting to a neurodegenerative disease," said Gonzales. "We don't have all the validation that we need in order to move these tests into the clinic, and one of the big areas that we're really lacking in is samples with diverse participants."

The study followed 745 Mexican Americans participating in the Texas Alzheimer's Research and Care Consortium (TARCC) study over four years. Among participants who developed Alzheimer's disease, researchers looked for six substances with known links to neurodegenerative diseases. 

One biomarker stood out as a predictor of dementia risk: glial fibrillary acidic protein, or GFAP, a component of supportive brain cells called astrocytes. Elevated GFAP in the blood can hint that such cells are damaged.

Gonzales says further studies are needed.

"But at this point, we've been able to show that at least this one biomarker was helpful in terms of making predictions," she said.