Association of physical activity with cognitive function, behavioral symptoms, and caregiver's burden in Chinese dementia patients

Abstract

Introduction: Dementia refers to impairments of memory and other cognitive functions with consequent decline in activities of daily living. Besides cognitive symptoms, demented patients can also exhibit behavioral and psychological symptoms of dementia (BPSD), which are stressors leading to family caregivers’ burden. Physical activity may give rise to benefits in cognitive function, and may reduce behavioral symptoms and caregivers’ burden. However, most previous studies were reported from Caucasian populations. There was no previous report on the relationship of physical activity in dementia patients on family caregiver’s burden in Hong Kong Chinese older adults.

Objectives: The objective of this study was to investigate the associations of physical activity level with cognitive function, behavioral and psychological symptoms and caregivers’ burden in dementia patients in Hong Kong Chinese population.

Method: This was a cross-sectional study. 201 dementia patients who were screened by the inclusion and exclusion criteria were recruited from the Geriatric Clinic in Queen Mary Hospital, Hong Kong, from May 2013 to August 2013. Social demographic information and comorbid diseases information were collected from all subjects. Subjects were then assessed with the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Alzheimer’s Disease Cooperative Study Activities of Daily Living Inventory (ADCS-ADL), Physical Activity Scale for the Elderly (PASE), as well as Neuropsychiatric Inventory (NPI). Subjects’ family caregivers were assessed with Zarit Burden Interview (ZBI).

Main outcome measures: The outcome measures for the cognitive function were the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). The outcome measures for BPSD and caregiver’s burden were the Neuropsychiatric Inventory (NPI) and Zarit Burden Interview (ZBI), respectively.

Results: We screened a total of 239 subjects in the Geriatric Clinic of Queen Mary Hospital. 201 subjects (70 males and 131 females) were recruited. 38 participants were excluded according to the exclusion criteria. The score means (SD) of the recruited were: PASE =27.5 (23.9); ADCS-ADL=45.3 (14.5); MMSE=17.3 (5.4); MoCA=9.9 (5.3); NPI=9.5 (9.7); ZBI=33.3 (14.8). In bivariate analysis, the PASE score was significantly associated with the MMSE score (rho=0.259, p<0.001), the MoCA score (rho=0.311, p<0.001), the NPI score (rho=-0.225, p=0.001), and the ZBI score (rho=-0.253, p<0.001). In multivariate analyses, using general linear models, the PASE score was independently associated with the MMSE (F=5.57, p=0.001) and MoCA (F=7.10, p<0.001) scores, after adjusting for significant confounders in bivariate analyses (i.e. age, education and gender). The PASE was also independently associated with the NPI score (F=2.89, p=0.037). The PASE score was not an independent predictor of the ZBI score. However, the subjects’ ADCS-ADL score (F=15.65, p<0.001), and the NPI score (F=8.55, p=0.004) were independent predictors of the caregiver’s ZBI score.