Association of APOE polymorphisms and stressful life events with dementia in a Pakistani population.

Dementia is a major public health problem worldwide. Alzheimer's disease (AD) is a major form of dementia and the APOE 4 allele is an established genetic risk factor for AD. Similarly, stressful life events are also associated with dementia. The objective of this study was to examine the association of APOE 4 and stressful life events with dementia in a Pakistani sample, which to our knowledge has not been reported previously. We also tested for an interaction between stressful life events and APOE 4 on dementia risk. A total of 176 subjects (61 cases and 115 controls) were recruited. All cases and healthy controls were interviewed to assess cognition, co-morbidities, history of stressful life events and demographics. Blood genotyping for the APOE polymorphism (E2/E3/E4) was performed. APOE 4 and stressful life events were each independently and significantly associated with the risk of dementia (APOE 4: P=0.00697; stressful life events: P=5.29E-09). However, we did not find a significant interaction between APOE 4 carrier status and stressful life events on risk of dementia (P=0.677). Although the sample size of this study was small, the established association of APOE 4 with dementia was confirmed the first time in a Pakistani sample. Furthermore, stressful life events were also found to be significantly associated with dementia in this population.