Background: The prevalence of AD appears to vary widely in different ethnic
groups. Certain risk factors for AD are well established for the general p
opulation, but there is little information regarding the relevance of these
risk factors in specific ethnic groups. Objective: The authors examined th
e risk of AD associated with the APOE-epsilon 4 allele, the APOE-epsilon 2
allele, smoking, alcohol consumption, history of hypertension, low educatio
nal level, estrogen replacement therapy, and history of head trauma with lo
ss of consciousness among samples of white non-Hispanics (WNH) (392 AD pati
ents, 202 normal subjects) and white Hispanics (WHIS) (188 AD patients, 84
normal controls). Design: This was a case-control study of patients evaluat
ed at an outpatient memory disorders clinic and control subjects recruited
from a free memory screening offered to the community. Results: Increased r
isk for AD was associated with the APOE-epsilon 4 allele after controlling
for age, education, and gender among WNH (OR = 3.5; 95% CI = 2.3 to 5.5) an
d WHIS (OR = 3.1; 95% CI = 1.7 to 5.8). No protective effect was conferred
by the APOE-epsilon 2 allele, although this relationship approached signifi
cance among WNH (p = 0.02). Low levels of education increased the risk for
AD among WNH (OR = 3.1; 95% CI = 1.8 to 5.9) but not WHIS. Alcohol use and
hypertension approached significance as risk factors in WNH (p < 0.05) but
not WHIS. Estrogen replacement treatment approached significance as a prote
ctive factor in both ethnic groups (p < 0.05). Conclusions: Although the AP
OE-epsilon 4 allele is a risk factor for AD among WHIS and WNH, other risk
factors such as low education and hypertension appear to be important only
for WNH. Risk factors for AD reported or suggested previously that were not
confirmed by this study include smoking and head trauma with loss of consc
iousness.