Blood-based biomarkers may predict mild behavioral impairment in older Asian adults

Key takeaways:

• Higher baseline biomarkers were linked to increased severity of neuropsychiatric conditions.
• Higher p-tau181 levels were linked to higher likelihood of incident MBI among those with dementia.

Analysis of blood-based biomarkers may be a reliable method to predict behavioral issues in older populations of Asian descent with varied neuropathology, researchers reported in the Journal of Clinical Psychiatry.

Neuropsychiatric disturbances are frequently observed across all stages of dementia and suggested as an early manifestation of Alzheimer’s disease,” Yingqi Liao, MSc, a doctoral student in the Memory, Aging and Cognition Center, Yong Loo Lin School of Medicine, National University of Singapore, and colleagues wrote. “This has led to the concept of mild behavioral impairment, which is characterized by late-life emergent and persistent behavioral changes in the dementia-free population.”

Liao and fellow researchers sought to examine the mechanisms behind mild behavioral impairment (MBI) and whether a series of Alzheimer’s disease-related blood-based biomarkers could predict its incidence in a small cohort of older adults of Asian descent.

Their analysis of an ongoing prospective cohort study included 305 dementia-free individuals (52.5% female) recruited from Singaporean community and memory clinics between August 2010 and April 2022.

Participants were aged 50 years and older and had either no cognitive impairment or AD without dementia. All underwent a battery of cognitive, neuropsychiatric and clinical examinations each year along with biennial neuroimaging from baseline to the 5-year mark.

Blood draws were collected in a non-fasting state and analyzed for presence of three biomarkers indicative of AD pathology: plasma phosphorylated tau-181 (p-tau181), neurofilament light chain (NfL) and amyloid-beta 42. MRI imaging included T1 and T2 weighted sequences, while hippocampal volume (HV) and white matter hyperintensities (WMH) were also acquired.

A total of 248 individuals had no MBI at baseline and 57 were diagnosed with baseline MBI.

According to results, within 5 years, 55 individuals of the 248 without baseline MBI developed the condition.

The researchers also reported a correlation between a higher baseline ratio of p-tau181/amyloid-beta 42, presence of NfL and an increased severity of neuropsychiatric conditions as well as MBI incidence.

Additionally, higher p-tau181 levels were associated with a higher likelihood of incident MBI in the 16 individuals found to have incident dementia prior to onset of behavioral symptoms. However, they noted that no significant associations were found with incident MBI when adjusting for NfL levels, HV or WMH with respect to t-tau181/amyloid-beta 42 ratio.

“Given that p-tau181/amyloid-beta 42 ratio has taken into consideration of both amyloid and phosphorylated tau levels, this biomarker could potentially be a more sensitive marker for screening [mild behavioral impairment] in cohorts of diverse clinical profiles,” Liao and colleagues wrote.