Anticholinergic burden and functional status in older people with cognitive impairment: Results from the ReGAl project

Objective: The use of drugs with intrinsic anticholinergic properties is widespread among old age persons. A growing body of evidences suggest that a high anticholinergic burden is associated with physical and cognitive impairment. However, the association between anticholinergic drug use and functional status is still poorly investigated, particularly among subjects with initial cognitive impairment. Design: Cross-sectional study examining the association between drug-related anticholinergic burden and functional status in cognitively healthy (CH) (n=691), mild cognitive impairment (MCI) (n=541) or mild Alzheimer’s diseases (AD) (n=1127) subjects. Setting: Data were gathered from the ReGAl project (Rete Geriatrica Alzheimer-Geriatric Network on Alzheimer’s disease), a large longitudinal Italian multicentric clinical-based study, promoted by the Italian Society of Gerontology and Geriatrics (SIGG). Participants: 2359 outpatients, older than 65 years, admitted to memory clinics. The total sample size, estimated according to a global effect size of 25% with type I error of 0.05 and a power of 95% is 2010 subjects. Measurement: Functional status was evaluated by the Katz Index of Independence in Activities of Daily Living (ADL) and the Lawton-Brody Instrumental Activities of Daily Living (IADL) scales. The drug-related anticholinergic burden was estimated by the Anticholinergic Risk Scale (ARS). Results: The 15.9 % (n=375) of total population used at least one drug with anticholinergic properties. Such a drug use was associated with partially dependence in ADL (OR:1.42, CI95%: 1.10-1.83; p=0.006), independently of gender, number of drugs, comorbidity index, presence of clinically relevant neuropsychiatric symptoms and adjusted MMSE. Anticholinergic drug use was associated with un-ability at each IADL task only in male MCI subjects, with significant impairment in shopping (p=0.011), and drug management (p=0.05). Conclusions: The use of medications with anticholinergic properties is common among older persons cognitively health as well as with cognitive impairment. Our results suggest that the use of anticholinergic drugs is associated with functional impairment, especially in old age subjects with initial cognitive impairment. Minimizing anticholinergic burden should result in maintaining daily functioning, especially in a vulnerable population, such as MCI and mild AD.