Relationships Between a New Cultured Cell-Based Serum Anticholinergic Activity Assay and Anticholinergic Burden Scales or Cognitive Performance in Older Adults.

OBJECTIVES

Anticholinergic burden has been associated with deleterious effects on cognition particularly in those with an underlying brain disorder. We developed a new assay based on cultured cells to measure serum anticholinergic activity (cSAA). We report on its relationships with established anticholinergic burden rating scales and cognitive assessments in older patients with mild cognitive impairment (MCI) or major depressive disorder (MDD) in remission or both.

DESIGN

The study was cross sectional in nature.

SETTING

This was a five-centre study conducted in Toronto, Canada.

PARTICIPANTS

Serum samples were collected and cSAA levels were measured in 311 participants aged 60 years or older (154 with MCI, 57 with MDD, and 100 with MCI + MDD).

MEASUREMENTS: The cSAA assay uses radio-ligand binding to cultured cells stably expressing the muscarinic M1 receptors, with an added procedure to remove potential confounds associated with serum proteins. Lists of medications were used to calculate Anticholinergic Burden and Anticholinergic Drug Scale total scores. Participants also completed a comprehensive cognitive battery.

RESULTS

Higher cSAA levels were associated with higher anticholinergic burden and anticholinergic drug scale scores, and also with lower performance on executive function tests, after adjusting for age, gender, education, and diagnosis.

CONCLUSIONS

These results support the use of the cSAA assay as a laboratory measure of anticholinergic burden.