Signs Alzheimer’s disease has started developing can be spotted early through a simple urine test, says a new study.

Alzheimer’s disease might go unnoticed for years until it is too late to cure. Large-scale screening programs might be used to find diseases in their early stages, but the existing diagnostic approaches are too time-consuming and costly.

The discovery of formic acid as a sensitive urine biomarker that can detect early-stage Alzheimer’s disease in new research published in Frontiers may pave the way for low-cost and simple disease screening.

But could a simple urine test detect Alzheimer’s disease in its early stages?

Undoubtedly, according to a new study published in Frontiers in Aging Neuroscience.

Researchers looked for differences in urine biomarkers by testing a large group of Alzheimer’s patients with different levels of disease and a group of healthy people with normal thinking.

They discovered that formic acid levels in the urine are a sensitive indicator of subjective cognitive impairment and may even point to the very early stages of Alzheimer’s disease.

The ways that Alzheimer’s is currently diagnosed are expensive, inconvenient, and not good for routine screening. This implies that the majority of patients obtain a diagnosis when it is too late to provide appropriate therapy.

However, a noninvasive, affordable, and easy urine test for formic acid may be just what the doctor prescribed for early screening.

According to scientists, Alzheimer’s disease may develop and persist for many years before evident cognitive impairment shows up since it is a continuous and disguised chronic disease. 

“The early stages of the disease occur before the irreversible dementia stage, and this is the golden window for intervention and treatment. Therefore, large-scale screening for early-stage Alzheimer’s disease is necessary for the elderly.”

Tests for Alzheimer’s?

Given the importance of intervening early, one would wonder why we don’t already have widespread screening for mild forms of Alzheimer’s. The problem is with the ways that doctors make diagnoses right now.

Some of these are expensive positron emission tomography (PET) brain scans that expose the patient to radiation.

There are additional biomarker tests that may detect Alzheimer’s disease; however, they involve invasive blood draws or a lumbar puncture to gather cerebrospinal fluid, which can be unsettling for patients.

But a urine test is easy and doesn’t hurt, so it would be good for screening a lot of people at once.

Researchers have previously identified Alzheimer’s disease biomarkers in urine, but none of them has been able to detect the disease in its earliest stages.

This means that the golden window for early treatment is still hard to find.

Formic acid: golden key?

The authors of the current work had previously looked at the possibility of using formaldehyde in the urine as an Alzheimer’s biomarker.

But there remained space for development in the area of early illness detection.

In this most recent research, formic acid, a metabolic byproduct of formaldehyde, was examined to see if it functioned better as a biomarker.

There were a total of 574 people in the study. Some were healthy volunteers with normal cognition, while others had different stages of disease progression, from subjective cognitive decline to full-blown disease.

In addition to analyzing the subjects’ blood and urine samples, the researchers also administered psychological tests.

Exposing Alzheimer’s disease at its earliest stages

The study found that all of the Alzheimer’s groups, including the early-stage subjective cognitive decline group, had significantly higher levels of formic acid in their urine than the healthy control group. This was linked to a decline in cognitive function.

According to these findings, formic acid has the potential to serve as a sensitive biomarker for Alzheimer’s disease in its early stages.

When the researchers looked at the levels of formic acid in a patient’s urine along with Alzheimer’s biomarkers in their blood, they found that they could more accurately tell what stage of the disease a patient was in. But more research needs to be done to figure out what the link is between Alzheimer’s and formic acid.

“Urinary formic acid showed an excellent sensitivity for early Alzheimer’s screening,” add the authors. “The detection of urine biomarkers of Alzheimer’s is convenient and cost-effective, and it should be performed during routine physical examinations of the elderly.”

Source: 10.3389/fnagi.2022.1046066

Image Credit:  John Tlumacki/The Boston Globe via Getty Images