APOA2, dietary fat, and body mass index: replication of a gene-diet interaction in 3 independent populations.
BACKGROUND
Nutrigenetics studies the role of genetic variation on interactions between diet and health, aiming to provide more personalized dietary advice. However, replication has been low. Our aim was to study interaction among a functional APOA2 polymorphism, food intake, and body mass index (BMI) in independent populations to replicate findings and to increase their evidence level.


METHODS
Cross-sectional, follow-up (20 years), and case-control analyses were undertaken in 3 independent populations. We analyzed gene-diet interactions between the APOA2 -265T>C polymorphism and saturated fat intake on BMI and obesity in 3462 individuals from 3 populations in the United States: the Framingham Offspring Study (1454 whites), the Genetics of Lipid Lowering Drugs and Diet Network Study (1078 whites), and Boston-Puerto Rican Centers on Population Health and Health Disparities Study (930 Hispanics of Caribbean origin).


RESULTS
Prevalence of the CC genotype in study participants ranged from 10.5% to 16.2%. We identified statistically significant interactions between the APOA2 -265T>C and saturated fat regarding BMI in all 3 populations. Thus, the magnitude of the difference in BMI between the individuals with the CC and TT+TC genotypes differed by saturated fat. A mean increase in BMI of 6.2% (range, 4.3%-7.9%; P = .01) was observed between genotypes with high- (> or =22 g/d) but not with low- saturated fat intake in all studies. Likewise, the CC genotype was significantly associated with higher obesity prevalence in all populations only in the high-saturated fat stratum. Meta-analysis estimations of obesity for individuals with the CC genotype compared with the TT+TC genotype were an odds ratio of 1.84 (95% confidence interval, 1.38-2.47; P < .001) in the high-saturated fat stratum, but no association was detected in the low-saturated fat stratum (odds ratio, 0.81; 95% confidence interval, 0.59-1.11; P = .18).


CONCLUSIONS
For the first time to our knowledge, a gene-diet interaction influencing BMI and obesity has been strongly and consistently replicated in 3 independent populations.
Corella
Dolores
D
Nutrition and Genomics Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, 711 Washington St, Boston, MA 02111-1524, USA.
Peloso
Gina
G
Arnett
Donna K
DK
Demissie
Serkalem
S
Cupples
L Adrienne
LA
Tucker
Katherine
K
Lai
Chao-Qiang
CQ
Parnell
Laurence D
LD
Coltell
Oscar
O
Lee
Yu-Chi
YC
Ordovas
Jose M
JM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016633:Apolipoprotein A-II / Q000235:genetics*; D001823:Body Composition / Q000235:genetics*; D015992:Body Mass Index; D016022:Case-Control Studies; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D004041:Dietary Fats / Q000009:adverse effects*; D004435:Eating / Q000235:genetics; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009752:Nutritional Status / Q000235:genetics; D009765:Obesity / Q000178:diet therapy* / Q000208:ethnology / Q000235:genetics*; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D011336:Probability; D018570:Risk Assessment; D044465:White People / Q000235:genetics
D016633:Apolipoprotein A-II; D004041:Dietary Fats