Risk factors for dementia in central Nigeria.

Little is known about the prevalence of dementia and its associated risk factors in developing countries. Some studies suggest that the prevalence of dementia is lower in developing countries than it is in high-income nations. We sought to determine risk factors for dementia in elderly persons in central Nigeria. Using the standardized Community Screening Instrument for Dementia, we screened a stratified, random community sample of 280 persons aged 65 years and older for dementia. We examined the independent association of known risk factors with dementia using logistic regression. The overall prevalence of dementia was 6.4% (95% CI 3.8-9.9%). Independent risk factors for dementia included female sex (OR 8.4; 95% CI 1.9-39), body mass index of 18.5 kg/m2 or less (OR 3.5; 95% CI 1.2-9.9), and age (OR 1.05 per year; 95% CI 1.00-1.11). Non-steroidal anti-inflammatory drug (NSAID) use was associated with a reduced risk of dementia (OR 0.20; 95% CI 0.04-0.93). Education, blood pressure, history of stroke, family history of dementia, and rural residence were not significantly associated with dementia in the multivariate model. The prevalence of dementia in central Nigeria may be greater than that found in other developing countries. Female sex, low body mass index, lack of NSAID use, and advancing age were the major risk factors in this population.