Figure 3. Interaction between the APOA2 -265T>C polymorphism and SATFAT intake on BMI in the Boston-Puerto Rican Study.

In Panel A, predicted values of BMI by the APOA2 -265T>C polymorphism (n=832 carriers of the T allele and n=98 CC subjects) depending on the SATFAT consumed (as continuous) in both men and women are depicted. Predicted values were calculated from the regression models containing the SATFAT intake, the APOA2 polymorphism, their interaction term, and the potential confounders [sex, age (as continuous), tobacco smoking (as categorical), alcohol consumption (as categorical), diabetes status (as categorical), cholesterol medication (as categorical) and total energy intake (as continuous). To estimate these predicted values, BMI was first adjusted for covariates and the residuals used as dependent variable in the model containing the interaction variables. The P value for the interaction term was obtained in the multivariate interaction model. Round and squared symbols represent estimated values for T-allele carriers and CC subjects, respectively. R² in Figure refers to all the variables in the model (r²: 0.012; P=0.008 for the interaction variables). In the stratified analysis by genotype, multivariate adjusted regression coefficients (B), 95%CI and the corresponding P values were estimated after adjustment for the described covariates. Further adjustment for other macronutrients including carbohydrates (as continuous), proteins (as continuous) and total fat (as continuous) did not change the statistical significance of the interaction term or of regression coefficients. Panel B represents means of BMI in both men and women depending on the APOA2 -265T>C polymorphism according to the strata of SATFAT intake (below and above 22g/d). Estimated means were adjusted for sex, age (as continuous), tobacco smoking (as categorical), alcohol consumption (as categorical), diabetes status (as categorical), cholesterol medication (as categorical) and total energy intake (as continuous). P value for the interaction term between SATFAT intake (as dichotomous) and the APOA2 polymorphism were obtained in the multivariate interaction model. In the stratified analysis by SATFAT intake levels, P values for mean comparisons of BMI between APOA2 genotypes were estimated after multivariate adjustment for the covariates indicated above. Further adjustment for the other macronutrients including carbohydrates (as continuous), proteins (as continuous) and total fat (as continuous) did not change the statistical significance of the interaction term or of the P values in the stratified analyses. Bars indicate standard error (SE) of means.