Amino acid change in the carbohydrate response element binding protein is associated with lower triglycerides and myocardial infarction incidence depending on level of adherence to the Mediterranean diet in the PREDIMED trial

Background: A variant (rs3812316, C771G, and Gln241His) in the MLXIPL (Max-like protein X interacting protein-like) gene encoding the carbohydrate response element binding protein has been associated with lower triglycerides. However, its association with cardiovascular diseases and gene-diet interactions modulating these traits are unknown. Methods and Results: We studied 7166 participants in the PREvención with DIeta MEDiterránea trial testing a Mediterranean diet (MedDiet) intervention versus a control diet for cardiovascular prevention, with a median follow-up of 4.8 years. Diet, lipids, MLXIPL polymorphisms, and cardiovascular events were assessed. Data were analyzed at baseline and longitudinally. We used multivariable-adjusted Cox regression to estimate hazard ratios for cardiovascular outcomes. The MLXIPL-rs3812316 was associated with lower baseline triglycerides (P=5.5×10-5) and lower hypertriglyceridemia (odds ratio, 0.73; 95% confidence interval [CI], 0.63-0.85; P=1.4×10-6 in G-carriers versus CC). This association was modulated by baseline adherence to MedDiet. When adherence to MedDiet was high, the protection was stronger (odds ratio, 0.63; 95% CI, 0.51-0.77; P=8.6×10-6) than when adherence to MedDiet was low (odds ratio, 0.88; 95% CI, 0.70-1.09; P=0.219). Throughout the follow-up, both the MLXIPL-rs3812316 (P=3.8×10-6) and the MedDiet intervention (P=0.030) were significantly associated with decreased triglycerides. Likewise in G-carriers MedDiet intervention was associated with greater total cardiovascular risk reduction and specifically for myocardial infarction. In the MedDiet, but not in the control group, we observed lower myocardial infarction incidence in G-carriers versus CC (hazard ratios, 0.34; 95% CI, 0.12-0.93; P=0.036 and 0.90; 95% CI, 0.35-2.33; P=0.830, respectively). Conclusions: Our novel results suggest that MedDiet enhances the triglyceride-lowering effect of the MLXIPL-rs3812316 variant and strengthens its protective effect on myocardial infarction incidence. © 2014 American Heart Association, Inc.
Study supported by the Ministry of Economy and the Fondo Europeo de Desarrollo Regional (projects CIBER 06/03, PI07-0954, CNIC-06, PI11/02505, SAF2009-12304 and AGL2010-22319-C03-03), by contracts 53-K06-5 to 10 and 58-1950-9-001 from the US Department of Agriculture Research Service, USA and by the Generalitat Valenciana, Spain (AP-042/11, ACOMP/2012/190, ACOMP/2013/159, and ACOMP/213/165). M. Fitó was supported by the Instituto de Salud Carlos III and the Catalan Government, CP06/00100.