Determinants and consequences of adherence to the dietary approaches to stop hypertension diet in African-American and white adults with high blood pressure: results from the ENCORE trial.

BACKGROUND: Although the Dietary Approaches to Stop Hypertension (DASH) diet is an accepted nonpharmacologic treatment for hypertension, little is known about what patient characteristics affect dietary adherence and what level of adherence is needed to reduce blood pressure (BP). OBJECTIVE: Our aim was to determine what factors predict dietary adherence and the extent to which dietary adherence is necessary to produce clinically meaningful BP reductions. DESIGN: Ancillary study of the ENCORE (Exercise and Nutrition Interventions for Cardiovascular Health) trial--a 16-week randomized clinical trial of diet and exercise. PARTICIPANTS/SETTING: Participants included 144 sedentary, overweight, or obese adults (body mass index 25 to 39.9) with high BP (systolic 130 to 159 mm Hg and/or diastolic 85 to 99 mm Hg). INTERVENTION: Patients were randomized to one of three groups: DASH diet alone, DASH diet plus weight management, and Usual Diet Controls. MAIN OUTCOMES MEASURES: Our primary outcomes were a composite index of adherence to the DASH diet and clinic BP. STATISTICAL ANALYSES PERFORMED: General linear models were used to compare treatment groups on post-treatment adherence to the DASH diet. Linear regression was used to examine potential predictors of post-treatment DASH adherence. Analysis of covariance was used to examine the relation of adherence to the DASH diet and BP. RESULTS: Participants in the DASH diet plus weight management (16.1 systolic BP [SBP]; 95% CI 13.0 to 19.2 mm Hg and 9.9 diastolic BP [DBP]; 95% CI 8.1 to 11.6 mm Hg) and DASH diet alone (11.2 SBP; 95% CI 8.1 to 14.3 mm Hg and 7.5 DBP; 95% CI 5.8 to 9.3 mm Hg) groups showed significant reductions in BP in comparison with Usual Diet Controls participants (3.4 SBP; 95% CI 0.4 to 6.4 mm Hg and DBP 3.8; 95% CI 2.2 to 5.5 mm Hg). Greater post-treatment consumption of DASH foods was noted in both the DASH diet alone (mean = 6.20; 95% CI 5.83 to 6.57) and DASH diet plus weight management groups (mean = 6.23; 95% CI 5.88 to 6.59) compared with Usual Diet Controls (mean = 3.66; 95% CI 3.30 to 4.01; P<0.0001), and greater adherence to the DASH diet was associated with larger reductions in clinic SBP and DBP (P ≤ 0.01). Only ethnicity predicted dietary adherence, with African Americans less adherent to the DASH diet compared with whites (4.68; 95% CI 4.34 to 5.03 vs 5.83; 95% CI 5.50 to 6.11; P<0.001). CONCLUSIONS: Greater adherence to the DASH diet was associated with larger BP reductions independent of weight loss. African Americans were less likely to be adherent to the DASH dietary eating plan compared with whites, suggesting that culturally sensitive dietary strategies might be needed to improve adherence to the DASH diet.

A cost effective method of identifying and recruiting persons over 80 free of dementia or mild cognitive impairment.

For observational or prevention studies, accurately identifying by mail and telephone cognitively normal elderly volunteers would be cost effective. We describe how to recruit cognitively normal sib-pairs over age 80 using commercially available lists by age and ZIP code. We mailed an Institutional Review Board-approved letter to 24,366 persons over 85 around Jacksonville, FL, and received approximately 3,000 postcard replies with approximately 500 answering 3 screening statements affirmatively. Of these, we recruited 128 persons who underwent both in-person and telephone evaluations, the latter using the Telephone Interview of Cognitive Status-modified (TICS-m) and Clinical Dementia Rating scale (CDR). Blinded to the TICS-m and CDR data, clinicians made a consensus diagnosis for each participant, 120 were normal and 8 had mild cognitive impairment. With CDR, 119 patients (93%) screened as normal, and of these 115 (97%) were confirmed as normal with the consensus diagnosis. A TICS-m score cut-off of <29 resulted in a similar proportion of normals in the screened sample (97% or 103/106); however, 13 normal volunteers would have been excluded because they scored <29 on the TICS-m. Supplementing the sample, we recruited 12 age-matched cases having consensus diagnosis of dementia (n=2) or mild cognitive impairment (n=10). A CDR>0 correctly identified 12/12, whereas the TICS-m <29 correctly identified 7/12. Hearing loss present in 50% did not influence TICS-m or CDR performance. Using stringent entry criteria and the telephone CDR, this method accurately identified normal elderly persons.

Apolipoprotein epsilon4 allele frequency in young Africans of Ugandan descent versus African Americans.

Through its role in lipid metabolism, Apolipoprotein epsilon4 (ApoE4) may affect "brain repair" in stroke, brain hemorrhage, Alzheimer's disease, and other brain injury syndromes for which African Americans may have greater morbidity and mortality. Cross-cultural evaluations of these and other genetic factors may provide insight on possible ethnic differences in risk of morbidity to acute central nervous system (CNS) injury and chronic neurodegenerative processes. As an initial step toward expanding knowledge of ApoE allele frequencies for persons of African descent, we compared ApoE genotype of a group of 70 young Ugandans to 59 (subset of a larger group of 342 African Americans of all ages) age-matched African Americans and to published frequencies for Caucasians and Asians. We found that the ApoE4 and epsilon2 alleles are more frequent in Ugandans (U) than Caucasians (C) or Asians (A) with corresponding alleles showing significant elevations of epsilon2 (U 15.71%, C 8.40%, A 4.20%) and 14 (U 25%, C 13.70%, A 8.90%) (p < .001). Comparing the differences between Ugandans and age-appropriate African Americans (AA) was not statically significant, but this outcome may be due to small sample size. These results provide the only published ApoE frequencies for Ugandans and the complete set of data provides the largest published community group of ApoE frequencies for African Americans.