Vascular dementia among elderly Arabs in Wadi Ara

Dementia of the Alzheimer type (DAT) and vascular dementia (VaD) are the two major subtypes of dementia. In our epidemiological study of DAT in an Arab community in Wadi Ara, Israel, we found a high prevalence of late onset DAT. Illiteracy, smoking, diabetes mellitus (DM) and hypertension are very frequent in Wadi Ara. These factors led us to study the prevalence of VaD and various risk factors in this population. All people aged 60 years or older (n=823) in a defined region were examined for identification of DAT and VaD (DSM-IV criteria), using clinical examinations and a semi-structured questionnaire for detecting cognitive dysfunction. We identified 49 demented patients (29 males) fulfilling criteria of VaD with a prevalence rate of 49/823 (5.9%), compared to 168/823 (20.5%) for DAT. All had suffered from strokes. Male gender and hypertension were more common among VaD cases. Illiteracy was significantly more common among VaD patients than among healthy subjects (79.6% vs. 40.2%, P=0.001) but less common than among DAT patients (94.6%, P=0.001). Thus, our results show that VaD constitutes about 22% of the total dementia population in Wadi Ara. We confirm the association between VaD, illiteracy and hypertension. Smoking and gender do not represent risk factors for VaD in this population. While suggestive, DM is not a statistically significant risk factor for VaD.