The Cognitive Impact of Chronic Diseases on Functional Capacity in Community-Dwelling Adults

People with chronic diseases may experience poor cognitive functioning associated with advanced age, progression of disease, or other comorbid chronic conditions. Empirical evidence of this phenomenon is limited despite the clinical relevance of cognitive decline and associated adverse outcomes such as poor physical functioning.

The purpose of this study was to examine cognitive functioning in the domains of memory, attention, and executive function and its association with functional capacity in a sample of community-dwelling adults with a spectrum of chronic diseases.

An exploratory cross-sectional study was conducted in a sample of community-dwelling adults with chronic diseases, including hypertension (58.9%), diabetes mellitus (DM; 20.0%), and dyslipidemia (14.4%). Participants' mean age was 64.1 ± 11.2 years, and 48.9% were male. Ninety persons completed the face-to-face interviews, which evaluated cognitive functioning in the domains of memory, attention, and executive function using neuropsychological tests and the physical well-being test, which measured functional capacity using the Duke Activity Status Index.

Compared with those with other chronic diseases, our sample with hypertension and DM had significantly more memory loss and poorer executive function. These significant differences were nullified when adjusting for age, gender, and education. Approximately one third had functional limitations (n = 29, 32.2%), using a cutoff point of 35 or less (Duke Activity Status Index). Memory loss (delayed recall, b = 1.5, p = .016) and poor executive function (Trail Making Test Part A, b = -0.2, p < .001) were predicting factors of functional decline, independent of age, gender, education, and comorbidity.

Cognitive function, particularly memory and executive function, was poorer among chronically ill Korean adults in the community with hypertension or DM than their counterparts. Functional decline was worse in the presence of memory loss and poor executive function. Studies examining the mechanism by which overall functioning is impacted by cognitive decline and its relevance to functional declines in a larger representative sample are warranted.