Background: There are currently no published reports of dementia prevalence or factors associated with dementia occurrence in Bangladesh. The aims are to report the prevalence of definite and questionable dementia in rural Bangladesh, and examine factors potentially associated with dementia occurrence, including sociodemographic, clinical, social, and nutritional factors.

Methods: We used data from a population-based, cross-sectional study from Matlab, in rural Bangladesh, on 471 persons aged 60+ years. Participants underwent a clinical examination including diagnosis of somatic disorders, and a structured interview including questions about sociodemographic and social factors.  Nutritional status was measured with the Mini Nutritional Assessment, and blood tests were conducted to assess a range of nutritional and clinical aspects. Age- and sex-specific dementia prevalence was calculated.  Crude and adjusted logistic regression was used to examine associations between dementia and clinical,  social, and nutritional factors. Dementia was diagnosed using a two-step procedure by physicians according to DSM-IV criteria.

Results: The prevalence of questionable dementia was 11.5% and definite dementia was 3.6%. Dementia prevalence increased with increasing years of age (adjusted OR: 1.04; 95% CI = 1.002–1.1) and decreased with more years of education (adjusted OR: 0.8; 95% CI = 0.6–0.99). Being malnourished increased the odds of dementia almost six-fold (adjusted OR: 5.9; 95% CI = 1.3–26.3), while frequent participation in social activities was associated with a decreased odds (adjusted OR: 0.5; 95% CI = 0.2–0.9).

Conclusions: The prevalence of dementia in rural Bangladesh is similar to other countries in the South Asia region, but lower than reports from other world regions. Malnutrition is strongly associated with dementia occurrence, and is a relevant area for future research within low-income countries.