Apolipoprotein E polymorphism and Alzheimer disease: The Indo-US Cross-National Dementia Study.

Abstract

BACKGROUND:

The APOE*E4 allele of the gene for apolipoprotein E (APOE) has been reported as a risk factor for Alzheimer disease (AD) to varying degrees in different ethnic groups.

OBJECTIVE:

To compare APOE*E4-AD epidemiological associations in India and the United States in a cross-national epidemiological study.

DESIGN:

Case-control design within 2 cohort studies, using standardized cognitive screening and clinical evaluation to identify AD and other dementias and polymerase chain reaction to identify APOE genotyping.

PARTICIPANTS:

Rural community samples, aged 55 years or older (n=4450) in Ballabgarh, India, and 70 years or older (n=886) in the Monongahela Valley region of southwestern Pennsylvania.

MAIN OUTCOME MEASURES:

Criteria of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association for probable and possible AD and Clinical Dementia Rating (CDR) scale for dementia staging.

RESULTS:

Frequency of APOE*E4 was significantly lower (P<.001) in Ballabgarh vs the Monongahela Valley (0.07 vs 0.11). Frequency of probable or possible AD, with CDR of at least 1.0, in the Indian vs US samples, was as follows: aged 55 to 69 years, 0.1% (Indian sample only); aged 70 to 79 years, 0.7% vs 3.1%; aged 80 years or older, 4.0% vs 15.7%. Among those aged 70 years or older, adjusted odds ratios (95% confidence interval) for AD among carriers of APOE*E4 vs noncarriers were 3.4 (1.2-9.3) and 2.3 (1.3-4.0) in the Indian and US samples, respectively, and not significantly different between cohorts (P=. 20).

CONCLUSION:

This first report of APOE*E4 and AD from the Indian subcontinent shows very low prevalence of AD in Ballabgarh, India, but association of APOE*E4 with AD at similar strength in Indian and US samples. Arch Neurol. 2000.

• Authors: M Ganguli, V Chandra, M I Kamboh, J M Johnston, H H Dodge, B K Thelma, R C Juyal, R Pandav, S H Belle, S T DeKosky
• Journal: Archives of neurology (Arch Neurol) Vol. 57 Issue 6 Pg. 824-30 (Jun 2000) ISSN: 0003-9942 [Print] United States
• PMID: 10867779 (Publication Type: Clinical Trial, Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Apolipoproteins E

Topics

• Aged
• Aged, 80 and over
• Alzheimer Disease (genetics)
• Apolipoproteins E (genetics)
• Case-Control Studies
• Cohort Studies
• Cross-Cultural Comparison
• Female
• Humans
• India
• Male
• Middle Aged
• Pennsylvania
• Polymorphism, Genetic (genetics)
• Risk Factors
• Rural Population
• Treatment Outcome
• United States