RISK-FACTORS OF ALZHEIMERS-DISEASE - EPID EMIOLOGIC APPROACHES

During the last 20 years, numerous case-control or epidemiological stu dies have examined the environmental and genetic risk factors of Alzhe imer's disease. A review of available evidence indicates that smoking and chronic use of anti-inflammatory drugs might be associated with a decreased risk of Alzheimer's disease. However, this hypothesis is su] ,ported by data collected in case-control studies or in prevalence stu dies and must be confirmed in prospective cohort studies. About ten pe r cent of Alzheimer's disease cases are characterized by early onset a nd familial aggregation. Most of these cases have been recently linked to the presenilin 1 gene which is located on chromosome 14; in other families, the disease is associated is a mutation of the beta amyloid precursor gene on chromosome 21. The risk of late-onset sporadic cases depends upon the polymorphism of the apolipoprotein E gene; allele ep silon 4 carriers have a 4-time increased risk.