SHANGHAI, China — A simple and cheap urine test may be able to diagnose Alzheimer’s disease years before symptoms develop, according to new research. Scientists in China say the first signs of the disease are detectable in a chemical in urine.
Alzheimer’s disease is incurable, and medications fail to halt the condition because patients start treatment too late. Typically, that happens after symptoms like memory loss and confusion have already appeared.
The new discovery could lead to older people receiving a routine screening from their physician, with vulnerable patients receiving medications at a point in time when they are more likely to work. The results were based on a review of 574 individuals with various levels of cognitive decline. Those with dementia had increasing amounts of the organic compound formic acid.
“Alzheimer’s disease is a continuous and concealed chronic disease, meaning that it can develop and last for many years before obvious cognitive impairment emerges,” the study authors say in a media release.
“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.”
Currently, PET (positron emission tomography) scans or painful spinal lumbar punctures are necessary for a clinical diagnosis of dementia. Both procedures are costly. The study in Frontiers in Aging Neuroscience offers hope of an inexpensive and convenient alternative. It is the first to identify formic acid as a sensitive urinary biomarker.
What’s in urine that can signal Alzheimer’s disease?
Participants included patients with different levels of disease severity, ranging from mild cognitive impairment (MCI) to full-fledged Alzheimer’s disease — the most common form of dementia.
Analysis showed quantities of the biomarker were significantly higher in all Alzheimer’s groups including those in the primary stages, compared to peers with normal brain health. The team from Shanghai Jiao Tong University says this suggests that formic acid could act as a red flag for the very early-stages of Alzheimer’s.
Current methods are inappropriate for routine screening, meaning most patients only receive a diagnosis when it is too late for effective treatment. A non-invasive, inexpensive, and convenient urine test for formic acid could be “just what the doctor ordered,” the Chinese team explains.
Other urinary biomarkers for Alzheimer’s have been unsuitable to reveal the early stages of the disease, leaving the “golden window” elusive. These markers include formaldehyde. Formic acid, on the other hand, is a metabolic byproduct and a better bet for accurate diagnosis.
The researchers collected urine and blood samples and performed psychological evaluations. Interestingly, combining urinary formic acid levels in combination with blood-based Alzheimer’s biomarkers was even more accurate. It predicted what stage of the disease a patient was experiencing. However, further work is necessary to understand the link between Alzheimer’s and formic acid.
“Urinary formic acid showed an excellent sensitivity for early Alzheimer’s screening,” the researchers conclude. “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.”
Alzheimer’s and other forms of dementia affect over six million Americans. Worldwide, estimates predict that cases will triple beyond 150 million over the next three decades.
South West News Service writer Mark Waghorn contributed to this report.