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A recent study suggests that higher levels of urinary formic acid may be a biomarker for Alzheimer’s-related dementia. Zaharia_Bogdan/Getty Images
  • In a recent study, researchers in China recruited hundreds of participants with healthy cognition or dementia to study biomarkers for Alzheimer’s disease that can be detected early.
  • The researchers focused their study on urinary formic acid, a formaldehyde product.
  • By checking participants’ formic acid levels, the researchers learned that higher levels found in urine may point to impaired cognition.
  • The scientists hope the findings will lead to testing for early detection of Alzheimer’s that is inexpensive and accessible.

Alzheimer’s disease (AD) is a type of dementia that mainly affects older adults.

There is no cure for Alzheimer’s, but scientists are regularly exploring ways to treat symptoms of the disease.

Researchers are also working on early detection of Alzheimer’s disease-related dementia since earlier detection would aid treatment.

A new study published in Frontiers in Aging Neuroscience shows that urinary formic acid may be a potential biomarker for early AD diagnosis.

The Centers for Disease Control and Prevention(CDC) describes dementia as “the impaired ability to remember, think, or make decisions that interfere with doing everyday activities.”

In addition to Alzheimer’s, there are other forms of dementia, such as Lewy body dementia and vascular dementia. But Alzheimer’s disease is the most common form of dementia.

According to a 2022 report from the Alzheimer’s Association, an estimated 6.5 million people in the United States are living with the disease. Additionally, researchers expect this figure to more than double by 2050.

Some signs and symptoms of Alzheimer’s disease include:

  • difficulty remembering things
  • trouble with communication
  • changes in mood
  • behavioral changes

Also, people with later-stage Alzheimer’s disease may have trouble swallowing, speaking, and walking.

Before the early 2000s, an autopsy was the only method to confirm if an individual had Alzheimer’s disease or another form of dementia.

According to the National Institute on Aging, doctors can now check for the presence of biomarkers associated with Alzheimer’s disease by performing a lumbar puncture (also known as a spinal tap).

Doctors look for biomarkers such as beta-amyloid 42 (the major component of amyloid plaques in the brain) and can also look for abnormalities on PET scans.

“New imaging techniques, especially amyloid imaging, amyloid PET imaging, [and] tau PET imaging have allowed us to see the abnormalities in the brain while someone’s alive,” Dr. Kenneth M. Langa, professor and internist for the University of Michigan Health in Ann Arbor, not involved in the study, commented during a recent Michigan Medicine podcast.

Some treatment options are available to help lessen the severity of AD symptoms and slow the progression of the disease, although they will not cure it.

For example, doctors may choose to prescribe drugs such as donepezil or galantamine to decrease AD symptoms. An investigational medication called lecanemab may also slow the progression of Alzheimer’s.

Since testing for Alzheimer’s disease is expensive and may not be accessible to everyone, some researchers prioritize early screening.

Researchers from Shanghai Jiao Tong University and WuXi Diagnostics Innovation Research Institute in China collaborated to analyze the role of formic acid as an Alzheimer’s disease urinary biomarker.

The scientists chose this particular compound based on their previous research on Alzheimer’s disease biomarkers. They noted that abnormal formaldehyde metabolism is a key feature of age-related cognitive impairment.

For the study, the authors recruited 574 participants from the Memory Clinic of Shanghai Sixth People’s Hospital, China.

They grouped the participants into five groups based on how they performed on cognitive function tests; the groups ranged from healthy cognition to Alzheimer’s disease:

  • healthy cognition (71 participants)
  • subjective cognitive decline (101 participants)
  • cognitive impairment without mild cognitive impairment (131 participants)
  • mild cognitive impairment (158 participants)
  • Alzheimer’s disease (113 participants)

The researchers collected urine samples from the participants to analyze their formic acid levels and also took blood samples for DNA analysis.

After comparing the formic acid levels between each group, the researchers learned that there was a difference between the participants with healthy cognition versus those with at least some degree of impairment.

The groups with some level of cognitive decline all had higher urinary formic acid levels than the healthy cognition group.

Additionally, participants with Alzheimer’s disease had significantly higher levels of formic acid in their urine than those with healthy cognition.

The scientists also found a negative correlation between formic acid levels in urine and cognitive testing in the areas of memory and attention.

“There was a significant increase in urinary formic acid in the [subjective cognitive decline] diagnostic group, meaning that urinary formic acid can be used for the early diagnosis of [Alzheimer’s disease],” the authors wrote.

The findings of this study are important for several reasons, especially since Alzheimer’s can be expensive to diagnose.

If further studies indicate that urinary formic acid can detect cognitive decline, it may prove to be an accessible, affordable test.

Also, if such a test allows the detection of Alzheimer’s disease-related cognitive decline, then providers could provide interventions sooner.

Dr. Sandra Petersen, DNP, senior vice president of Health and Wellness at Pegasus Senior Living, spoke with Medical News Today about the study:

“Alzheimer’s disease changes start about 20 to 30 years before diagnosis, going generally undetected until significant damage has occurred. We know that early detection can lead to more treatment options and opportunities for planning future care for the sufferer.”

Dr. Petersen added that she believes the study findings’ potential could be “enormous.”

“A breakthrough in testing of this sort (noninvasive and inexpensive) available to the masses would be a definite game changer in the fight against Alzheimer’s Disease,” Dr. Petersen said.