Research from the University of Surrey has revealed that the timing of blood sample collection significantly influences biomarkers used for diagnosing dementia.

The study highlights the p-tau217 biomarker, essential for early dementia diagnosis, which exhibited significant variations throughout the day, reflecting changes in individuals with mild memory problems.

Participants in the study had blood samples taken every three hours over a 24-hour period, a method that contrasts with the typical single sample collection approach.

This comprehensive sampling revealed fluctuations in four out of five measured biomarkers, with GFAP being the only one that did not show significant variation.

While the exact causes of these daily variations remain unclear, factors such as sleep, meals, posture, activity, and circadian rhythms may play a role.

Dr. Ciro della Monica, the study's first author, emphasized the need for standardized timing in blood sample collection to enhance the accuracy of dementia diagnoses and monitoring.

Professor Derk-Jan Dijk, the senior author, noted that understanding circadian rhythms could significantly improve the diagnosis and treatment of Alzheimer's disease.

The study involved 38 participants, including individuals with mild Alzheimer's, their caregivers, and cognitively healthy controls, conducted at the Surrey Sleep Research Centre.

The findings of this study were published in the journal Translational Psychiatry, contributing valuable insights to dementia research.

Overall, the study underscores the importance of considering the time of day in dementia research and clinical diagnostics.

Biomarker levels for Alzheimer's were found to be lowest in the morning and highest in the evening, indicating a clear diurnal pattern.

These findings suggest that circadian rhythms may influence the production or clearance of Alzheimer's biomarkers, although the mechanisms behind this remain to be fully understood.