Predictive value of hypercholesterolemia, vegetarian diet, and hypertension for incident dementia among elderly Taiwanese individuals with low educational levels

Abstract

Objective: Early management of modifiable dementia-related factors is seen as a novel approach to preventing dementia onset; however, these efforts are often hindered by the complexity of interactions among these factors. In addition, different modifiable dementia-related factors may contribute to different etiologies of dementia.

Design: The current study investigated the effects of common modifiable dementia-related factors on prediction of incident dementia, dementia of the Alzheimer's type (DAT), and vascular dementia (VaD).

Methods: Vascular- and lifestyle-related factors were used as predictors of incident dementia, DAT, and VaD among 1,285 elderly individuals without obvious signs of dementia or mild cognitive impairment. Cox proportional hazard models were used to evaluate the risks associated with each modifiable factor.

Results: After controlling for factors other than stroke-related factors, hypercholesterolemia was correlated with a relatively low risk of all-cause incident dementia and DAT, whereas a vegetarian diet was correlated with an elevated risk of all-cause incident dementia and VaD. Hypertension was correlated with incident VaD. After controlling for stroke-related factors, a vegetarian diet was correlated with an elevated risk of all-cause dementia. A history of myocardiac infarction and the use of anti-platelet medication were, respectively, associated with a reduced risk of DAT and elevated risk of VaD. The use of anti-hypertensives was associated with a reduced risk of all-cause dementia, whereas the use of anti-lipid agents was associated with slow progression DAT (i.e. exceeding the average conversion time). Hypercholesterolemia was associated with an elevated risk for slow progression DAT.

Conclusion: These findings could perhaps be used as clinical markers in predicting and preventing incident dementia, DAT, and VaD.

Keywords: dementia; hypercholesterolemia; hypertension; modifiable factors; vegetarian diet.

Figure 1.

Selection of study participants. HAICDDS, History-Based Artificial Intelligent Clinical Dementia Diagnostic System; MCI, mild cognitive impairment.

Figure 2.

Hazard ratios of each factor for (a) all-cause dementia. (b) DAT. (c) VaD. The red diamonds denote statistically significant effects.

Figure 3.

Survival curve of all-cause dementia between (a) individuals with or without hypercholesterolemia and (b) individuals following an omnivore or vegetarian diet.

Figure 4.

ROC analysis.