A new study from Sweden shows that people with higher levels of a protein called albumin in their urine may have a greater risk of developing dementia.
The research was led by scientists at Karolinska Institutet and published in the Journal of Internal Medicine.
While aging is still the biggest factor linked to dementia, this study adds to growing evidence that health problems in other parts of the body—like the kidneys—can also affect the brain.
Normally, the protein albumin should stay in the blood. When it shows up in urine, it signals that the kidneys might not be working properly. This condition is called albuminuria. The researchers found that people with this condition were more likely to develop dementia, especially vascular dementia and mixed dementia.
Vascular dementia is caused by problems in blood flow to the brain and is often linked to strokes, high blood pressure, or diabetes. Mixed dementia combines symptoms of both vascular dementia and Alzheimer’s disease.
The study followed 130,000 people in Stockholm, all over the age of 65 and without dementia at the start. Over about four years, 7% of them developed some form of dementia.
After adjusting for other health factors, the researchers found that people with moderate levels of albumin in their urine had a 25% higher risk of dementia. Those with high levels had a 37% higher risk compared to people with normal albumin levels.
Why does this happen? According to the researchers, the kidneys and the brain have something in common: they both rely on small, delicate blood vessels to work properly. If these blood vessels get damaged in the kidneys, the same kind of damage may happen in the brain too.
One key part of this process involves the blood-brain barrier. This barrier normally keeps harmful substances in the blood from reaching the brain.
But just as damaged kidneys allow albumin to leak into urine, a damaged blood-brain barrier can let toxins and inflammatory molecules enter the brain. Over time, this may lead to brain inflammation and damage that can cause dementia.
Hong Xu, the lead researcher, said the findings show why it’s important to screen for albumin in urine. People with high blood pressure, diabetes, or heart or kidney disease should be tested regularly. Catching this problem early might help prevent or delay the development of dementia.
This study is one of the largest of its kind and highlights a simple test that could offer important clues about brain health. If doctors pay attention to early signs in the kidneys, they may be able to protect the brain too.
If you care about dementia, please read studies about Dizziness upon standing may be linked to dementia risk and findings of Scientists find the ties between high blood pressure and dementia.
For more about dementia, please read studies about Early heart rhythm problem linked to higher dementia risk and findings of Green leafy vegetables may help reduce Alzheimer’s risk.
The study is published in the Journal of Internal Medicine.
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