A study reveals how age, sex, and genetics impact dementia biomarker levels in blood.
A recent study has uncovered new details about the way factors like age, sex, and genetics impact certain biological markers linked to dementia. Published in the journal Neurology on April 16, 2025, the study explores how blood tests that track these biomarkers can help researchers better understand and eventually diagnose conditions like Alzheimer’s disease. These blood tests are becoming increasingly important in identifying people at risk for dementia, which could lead to earlier detection and treatment options.
The study, led by Dr. Hannah Stocker from Heidelberg University in Germany, focused on three key biomarkers: neurofilament light chain proteins, glial acidic proteins, and phosphorylated tau 181. These markers have been linked to dementia, including Alzheimer’s disease, in previous research. Neurofilament light chain proteins are released when nerve cells are damaged or die, glial acidic proteins are produced as the brain repairs itself, and phosphorylated tau 181 is associated with the buildup of amyloid proteins in the brain, which is a hallmark of Alzheimer’s.
To better understand how these markers are connected to dementia risk, the researchers analyzed data from a long-term study that lasted 17 years. They looked at blood samples from 1,026 participants, half of whom developed dementia during the study, and half who did not. The average age of participants when the study started was 64. Blood samples were collected from these participants three times during the study to track the levels of the three biomarkers.
The researchers made several important discoveries. They found that as people got older, the levels of these biomarkers generally increased. For example, participants who were 75 years old had much higher levels of neurofilament light chain proteins, glial acidic proteins, and phosphorylated tau 181 than those who were 50. Specifically, the older group had 2 to 3 times higher levels of these markers than the younger group.
The study also found some differences between men and women. Female participants had higher levels of glial acidic proteins, while male participants showed higher levels of neurofilament light chain proteins. This suggests that gender might influence the way the brain responds to injury or disease.
Another key finding was that people who carried a gene known as APOEe4, which is strongly linked to Alzheimer’s disease, had higher levels of phosphorylated tau 181 and glial acidic proteins. This supports earlier research showing that the APOEe4 gene increases the risk of developing dementia.
The study also looked at how menopause might affect biomarker levels in women. They found that pre-menopausal women had higher levels of glial acidic proteins, which could be related to the higher levels of sex hormones that women experience before menopause. These hormones have been linked to inflammation in the brain, which may play a role in the development of dementia.
Dr. Stocker noted that understanding these biomarkers better could make it easier to detect dementia in the future using simple blood tests. This would be a huge step forward in diagnosing dementia, as current methods often rely on expensive and time-consuming brain imaging or cognitive tests. By identifying people at risk earlier, doctors could start treatments sooner, which might slow the progression of dementia or help prevent it altogether.
However, the study has some limitations. For one, all the participants were of European descent, so it’s unclear whether the same patterns would hold true for other populations. Additionally, the study did not track changes in dementia biomarkers for individual patients over the entire study period, which could have provided more detailed insights.
Overall, this research provides a clearer picture of how age, sex, genetics, and menopause affect biomarkers linked to dementia. It highlights the need for further research to explore how these factors influence the brain and could eventually help scientists develop better tests and treatments for dementia in the future. With more understanding, the hope is that blood tests could become a simple yet effective way to diagnose dementia early, improving outcomes for patients and their families.
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