Nutrition and Genetics as Determinants of an Atherogenic Lipid Profile in African Americans: The Jackson Heart Study.
Background: There is limited research on the relationship between genes, nutrients and
cardiovascular disease (CVD) in African-Americans. Our objective was to investigate the
relationship between omega-3 fatty acids, trans fatty acids (TFA) and lipid metabolism
genes with serum lipid concentrations in the Jackson Heart Study (JHS). In addition, we
aimed to determine the validity of ... read morea culturally specific food frequency questionnaire
(FFQ) in estimating omega-3 and TFA intake. Methods: Participants in JHS were between
the ages of 25-85 y at first interview. A subset of participants was included in the
Diet and Physical Activity Sub-Study (DPASS), a validation study of the diet and
physical activity questionnaires used in the JHS. A second subset of JHS participants
participated in a family study. We evaluated the correlation between dietary omega-3 and
TFA from a short food frequency questionnaire (SFFQ), a long food frequency
questionnaire (LFFQ), four, 24h recalls and plasma phospholipids (PL) in the JHS DPASS.
General linear models were used to evaluate the association between omega-3, TFA and six
SNPS in apolipoprotein-E (APOE), apolipoprotein-A5 (APOA5) and peroxisome
proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A). Variance component
analysis was used to assess heritability and Haseman-Elston regression analysis was used
to assess linkage in the JHS family study. Covariates included age, BMI, sex, energy
intake, smoking status, diabetes status and hypertension status. Results: Correlation
analysis showed that dietary measures from the LFFQ were significantly correlated with
plasma concentrations of total omega-3, docosahexaenoic (DHA), eicosapentaenoic acid
(EPA) and total TFA. Measures from the SFFQ were significantly correlated with EPA, DHA
(r=0.20) and total omega-3, but not with total TFA. The LFFQ and the SFFQ both appear to
be reasonably valid measurement tools for omega-3 intake in southern African Americans.
The LFFQ also appears to be valid for estimation of TFA intake in this population. Total
TFA estimated from the LFFQ was associated with fast food and southern dietary patterns.
Dietary 16:1t was positively associated with high density lipoprotein (HDL-C) and total
cholesterol. No other TFA were significantly associated with serum cholesterol. Total
omega-3 intake was positively associated with HDL-C. Total omega-3 intake was negatively
associated with total cholesterol. HDL-C, low density lipoprotein (LDL-C), triglycerides
(TG) and total cholesterol concentrations were significantly heritable. In a linkage
analysis, we found 12 peaks with LOD >3.0. Regions of significant linkage were found
for TG on 4 chromosomes; and 2 chromosomes for LDL-C and HDL-C. Associations with serum
lipid concentrations were identified with the rs7412 and rs429358 SNPs (APOE); the
rs3135506 SNP (APOA5) and the rs2970869 SNP (PPARGC1A). Significant interactions were
found between total dietary fat and rs662799 (APOA5) for HDL-C. Conclusion: We found
both nutritional and genetic associations with HDL-C, LDL-C, TG and total cholesterol.
These results suggest that further research on the relationships between genes,
nutrients and their interactions may prove beneficial to understanding the CVD burden in
Thesis (Ph.D.)--Tufts University, 2013.
Submitted to the Dept. of Nutritional Epidemiology.
Advisor: Katherine Tucker.
Committee: Alice Lichtenstein, Anita DeStefano, and Jose Ordovas.
Keywords: Nutrition, Epidemiology, and Genetics.read less