Association between apolipoprotein E genotype and Alzheimer disease in African American subjects.

BACKGROUND: The association between Alzheimer disease (AD) and genotypes at the apolipoprotein E (APOE) locus has been confirmed in numerous populations worldwide, but appears to be inconsistent in African American subjects. OBJECTIVE: To investigate the association between APOE genotypes and AD in elderly African American subjects. DESIGN: Clinic-based, multicenter case-control study and a family study. PARTICIPANTS: A total of 338 African American probands meeting criteria for probable or definite AD, 301 cognitively healthy, elderly unrelated control subjects (spouses and community volunteers), and 108 siblings of 88 AD probands. MAIN OUTCOME MEASURES: Odds of AD according to APOE genotype. RESULTS: Compared with individuals with the APOEepsilon3/epsilon3, the odds of having AD were significantly increased among those with 1 or more copies of the epsilon4 allele; the odds ratio (OR) for the epsilon3/epsilon4 genotype was 2.6 (95% confidence interval [CI], 1.8-3.7), and the OR for the epsilon4/epsilon4 genotype was 10.5 (95% CI, 5.1-21.8). These risks decreased substantially after 68 years of age. The risk for AD was lower among individuals with the epsilon2/epsilon3 genotype (OR, 0.41; 95% CI, 0.22-0.79). The patterns of association were similar in men and women. These results obtained from comparisons of unrelated AD patients and controls were bolstered by results of analysis of family data that showed preferential transmission of the epsilon4 allele to demented siblings (P<<.001) and of the epsilon2 allele to nondemented siblings (P=.005). CONCLUSIONS: The presence of 1 or 2 epsilon4 alleles is a determinant of AD risk in African American subjects. The age-related risk for decline associated with the epsilon4 allele and the apparent protective effect of the epsilon2 allele are similar to patterns observed in white subjects.

Differences between African Americans and Whites in their attitudes toward genetic testing for Alzheimer's disease.

The possibility of predictive genetic testing for Alzheimer's disease (AD) has prompted examination of public attitudes toward this controversial new health-care option. This is the first study to examine differences between Whites and African Americans with regard to: (1) interest in pursuing genetic testing for AD, (2) reasons for pursuing testing, (3) anticipated consequences of testing, and (4) beliefs about testing. We surveyed a convenience sample of 452 adults (61% white; 39% African American; 78% female; mean age = 47 years; 33% with family history of AD). Both racial groups indicated general interest in predictive genetic testing for AD, viewed it as having many potential benefits, and believed it should be offered with few restrictions. However, in comparison to whites, African Americans showed less interest in testing (p < 0.01), endorsed fewer reasons for pursuing it (p < 0.01), and anticipated fewer negative consequences from a positive test result (p < 0.001). These preliminary findings show important distinctions between whites and African Americans in their attitudes toward genetic testing for AD. These differences may have implications for how different racial and ethnic groups will respond to genetic testing programs and how such services should be designed. Future research in real-life testing situations with more representative samples will be necessary to confirm these racial and cultural differences in perceptions of genetic testing.

Self-reported quality of life in complementary and alternative medicine treatment of chronic rhinosinusitis among African Americans: a preliminary, open-label pilot study.

OBJECTIVE: The southern U.S. region has among the highest incidence of chronic rhinosinusitis (CRS). Historically, African Americans in this region have been a difficult to reach population for clinical research participation. This study's aim was to observe any association between herbal tea consumption and CRS symptoms among African Americans. We recount the volunteers self-reporting of measurements associated with self-treatment of CRS symptoms. DESIGN: The study design was a preliminary, open-label, pilot study. SETTINGS: Volunteers were drawn from Morehouse School of Medicine's outpatient clinics, community multipurpose senior centers, and churches in Fulton and DeKalb Counties, GA. SUBJECTS: One hundred (100) African American volunteers were prescreened, of whom 55 with a clinical diagnosis of CRS met entrance criteria. INTERVENTION: Volunteers self-administered Breathe Easy herbal tea for a duration of 6 weeks. OUTCOME MEASURES: The Chronic Sinusitis Survey (CSS) scale was administered to assess sinus health at baseline and term and overall quality of life was assessed using the Short Form-36 (SF-36) index. RESULTS: Of the 55 volunteers who met entrance criteria, 41 completed the study; groups were q.i.d. (n = 27), t.i.d. (n = 4), b.i.d. (n = 5), and noncompliant (n = 5). For the q.i.d. group (n = 27), there was a significant increase in the CSS symptom score (difference in means 22.0 points; p = 0.020) and CSS total score (11.1 points; p = 0.020). Overall health status (SF-36) reported at baseline was 35% very good; 34% good; and 17% fair. After 6-weeks, the q.i.d. group showed a significant change to 44% good and 45% very good (p = 0.001). CONCLUSIONS: This preliminary pilot study suggests that q.i.d. self-administration of Breathe Easy was associated with improved volunteers' sinus health status (e.g., ability to fall sleep). Our results suggest that this herbal tea may contribute as a complementary therapy for management of CRS among African Americans. To further assess efficacy and applicability to other populations, randomized controlled trials in larger populations are warranted.

Differences between African Americans and whites in their perceptions of Alzheimer disease.

To design optimal health services and education programs for Alzheimer disease (AD), it is important to understand cultural differences in perceptions of the disorder. In this study, we investigated differences between African Americans and whites in their beliefs, knowledge, and information sources regarding AD. We distributed a written questionnaire through lay and professional organizations and meetings in the southeastern United States, yielding a sample of 452 adults (61% white, 39% African American; 78% female; mean age 47 years; 33% with family history of AD). The questionnaire assessed the following: (1) illness beliefs, (2) factual knowledge, (3) sources of information, and (4) perceived subjective threat of AD. African Americans and whites were generally similar in their beliefs about common symptoms, prominent risk factors, and the effectiveness of treatments for AD (although whites expressed greater certainty in these beliefs than African Americans). In comparison to whites, African Americans showed less awareness of facts about AD, reported fewer sources of information, and indicated less perceived threat of the disorder. These preliminary findings suggest important distinctions between African Americans and whites in their knowledge about, and conceptualization of, AD. Follow-up studies with more representative samples and more fully validated measures will be necessary to confirm these differences. Health psychologic research suggests that such differences in illness perceptions could shape response to disease burden, assessment and diagnosis, and available health care options.

Risk of dementia among white and African American relatives of patients with Alzheimer disease.

CONTEXT: Evidence exists that the incidence of Alzheimer disease (AD), as well as risk attributable to specific genetic factors such as apolipoprotein E (APOE) genotype, may vary considerably among ethnic groups. Family studies of probands with AD offer an opportunity to evaluate lifetime risk of dementia among relatives of these probands. OBJECTIVE: To compare lifetime dementia risk estimates among relatives of white and African American probands with probable or definite AD. DESIGN AND SETTING: Risk analysis using data collected by questionnaire and supplemental records between May 1991 and March 2001 at 17 medical centers contributing to the Multi-Institutional Research in Alzheimer's Genetic Epidemiology Study. PARTICIPANTS: A total of 17 639 first-degree biological relatives and 2474 spouses of 2339 white AD probands, and 2281 first-degree biological relatives and 257 spouses of 255 African American AD probands. MAIN OUTCOME MEASURES: Cumulative risk of dementia by age 85 years, stratified by ethnicity and sex of relatives and by APOE genotype of probands. RESULTS: Cumulative risk of dementia in first-degree biological relatives of African American AD probands by age 85 years was 43.7% (SE, 3.1%), and the corresponding risk in first-degree biological relatives of white AD probands was 26.9% (SE, 0.8%), yielding a relative risk (RR) of 1.6 (95% confidence interval [CI], 1.4-1.9; P<.001). The risk in spouses of African American AD probands of 18.5% (SE, 8.4%) was also higher than the risk in white spouses of 10.4% (SE, 1.7%) but did not reach statistical significance (RR, 1.8; 95% CI, 0.5-6.0; P =.34), likely due to the smaller sample size of African Americans. The proportional increase in risk of dementia among white first-degree biological relatives compared with white spouses of 2.6 (95% CI, 2.1-3.2) was similar to that of 2.4 (95% CI, 1.3-4.4) in African American first-degree biological relatives compared with African American spouses. Female first-degree biological relatives of probands had a higher risk of developing dementia than did their male counterparts, among whites (31.2% vs 20.4%; RR, 1.5; 95% CI, 1.3-1.7; P<.001) as well as among African Americans, although this was not significant among African Americans (46.7% vs 40.1%; RR, 1.2; 95% CI, 0.9-1.7, P =.30). The patterns of risk among first-degree biological relatives stratified by APOE genotype of the probands were similar in white families and African American families. CONCLUSION: First-degree relatives of African Americans with AD have a higher cumulative risk of dementia than do those of whites with AD. However, in this study, the additional risk of dementia conferred by being a first-degree relative, by being female, or by the probability of having an APOE epsilon4 allele appeared similar in African American and white families. These data provide estimates of dementia risk that can be used to offer counseling to family members of patients with AD.