Urine Formaldehyde: A Non-Invasive Marker for AlzheimerâÂÂs Disease?

Given the dramatic increase in Alzheimer’s disease (AD) cases globally, the identification of a suitable biomarker in easily collectable samples (e.g. plasma, blood, saliva and urine) for diagnosing AD is therefore of utmost importance. Previous studies indicated that excess formaldehyde contributes to Aβ aggregation and Tau hyper phosphorylation, both phenomena directly linked to the progress of AD. Our 7 year’s cross-sectional survey showed that morning urine formaldehyde levels were correlated positively with the severe degree of sporadic dementia, suggesting that urine formaldehyde measurement most likely acts as a suitable non-invasive method to support diagnostic purposes. In this a short review article, we provide a short overview of the animal and clinical studies on the possible mechanisms of exogenous and endogenous factors cause formaldehyde accumulation, which plays a critical role in the pathogenesis of both genetic dementia and sporadic dementia. Urine formaldehyde will be of significant value for the non-invasive diagnosis of cognitive ability in AD, but the more sensitive method for detecting formaldehyde concentrations and a longitudinal (long-term follow-up) study would be required to prove conclusively such a relationship between urine formaldehyde and dementia.