Anticholinergic Medication Use, Dopaminergic Genotype, and Recurrent Falls

Area of Science:

• Gerontology
• Pharmacology
• Neuroscience

Background:

• Anticholinergic medications are linked to an increased risk of falls in older adults.
• Dopaminergic signaling pathways may influence an individual's susceptibility to anticholinergic side effects.
• Understanding genetic variations in dopaminergic systems could reveal protective mechanisms against medication-induced falls.

Purpose of the Study:

• To investigate the interaction between anticholinergic medication use and dopaminergic genotype on recurrent fall risk.
• To determine if genetic variations in dopamine signaling (COMT genotype) modify the association between anticholinergic use and falls over a 10-year period.

Main Methods:

• Analysis of data from 2,372 participants in the Health, Aging, and Body Composition (Health ABC) study.
• Medication use (highly anticholinergic) and recurrent falls (≥2 falls in 12 months) were assessed over 10 years.
• Generalized estimating equations were used to test associations, with effect modification analyzed by catechol-O-methyltransferase (COMT) genotype (Met/Met vs. Val carriers).

Main Results:

• Anticholinergic use was associated with a doubled odds of recurrent falls (aOR = 2.09).
• This association was significant in Val carriers (lower dopamine signaling) but not in Met/Met genotype individuals (higher dopamine signaling).
• Effect sizes for anticholinergic-associated falls were stronger when baseline fallers were excluded from the analysis.

Conclusions:

• Higher dopaminergic signaling, indicated by the COMT Met/Met genotype, may offer a protective effect against the increased fall risk associated with anticholinergic medications.
• Genetic assessment of dopaminergic function could aid in evaluating the risk-benefit profile of prescribing or discontinuing anticholinergic drugs in older adults.
• This research highlights the potential for pharmacogenetic approaches in personalized fall prevention strategies.