Religious affiliation and the risk of dementia in Taiwanese elderly.

INTRODUCTION: Religious affiliations vary across ethnic groups because of different cultural backgrounds. Some studies have explored the association between religious affiliation and cognitive decline. Only a small portion of patients with cognitive decline progress to dementia. However, the association between religious affiliation and dementia risk remains unclear. METHODS: In this case-control study, we recruited 280 patients with Alzheimer's disease (AD) and 138 with vascular dementia (VaD) (both aged ≥60 years) from three teaching hospitals in northern Taiwan between 2007 and 2010. Age-matched healthy controls (n=466) were recruited from an elderly health checkup program and from volunteers visiting the hospital during the same period. Three religious affiliations-Taoism, Buddhism, and Christianity-were evaluated. The study also assessed the effect of important factors such as gender or leisure activities on the association of religious affiliation with dementia risk. RESULTS: Participants with Christianity affiliation showed decreased AD risk (adjusted odds ratio [AOR]=0.46, 95% confidence interval [CI]=0.25-0.87) compared with those without any religious affiliation. Moreover, this effect was stronger in women (AOR=0.38, 95% CI=0.15-0.92) and in participants who exercised regularly (>3 times/week; AOR=0.33, 95% CI=0.14-0.77). No significant association was observed among participants with Taoism and Buddhism affiliations. Affiliation to none of the religions was associated with VaD risk. CONCLUSIONS: Thus, Chinese participants having Christianity affiliation showed decreased AD risk. Moreover, the protective effect was more evident in women and in participants who exercised regularly.

Leisure activities, apolipoprotein E e4 status, and the risk of dementia.

BACKGROUND/PURPOSE: Leisure activities have been associated with a decreased risk of dementia. However, to date, no study has explored how apolipoprotein E (ApoE) e4 status or vascular risk factors modified the association between leisure activities and dementia risks. METHODS: This case-control study recruited patients (age ≥ 60 years) with Alzheimer's disease (AD; n = 292) and vascular dementia (VaD; n = 144) and healthy controls (n = 506) from three teaching hospitals in Taiwan between 2007 and 2010. Information on patient's leisure activities were obtained through a questionnaire. Conditional logistic regression models were used to assess the association of leisure activities and ApoE e4 status with the risk of dementia. RESULTS: High-frequency physical activity was associated with a decreased risk of AD [adjusted odds ratio (AOR) = 0.45], and the results become more evident among ApoE e4 carriers with AD (AOR = 0.30) and VaD (AOR = 0.26). Similar findings were observed for cognitive (AOR = 0.42) and social activities (AOR = 0.55) for AD. High-frequency physical, cognitive, and social activities were associated with a decreased risk of VaD (AOR = 0.29-0.60). Physical and social activities significantly interacted with each other on the risk of VaD (pinteraction = 0.04). CONCLUSION: Physical activity consistently protects against AD and VaD. Significant interactions were identified across different types of leisure activities in lowering dementia risk.