Sugar-sweetened beverage intake, chromosome 9p21 variants, and risk of myocardial infarction in Hispanics

Background: Chromosome 9p21 variants are among the most robust genetic markers for coronary artery disease (CAD), and previous studies have suggested that genetic effects of this locus might be modified by dietary factors. Intake of sugar-sweetened beverages (SSBs), which are the main dietary source of added sugar, has been shown to interact with genetic factors in affecting CAD risk factors such as obesity. Objective: We aimed to test whether SSB intake modified the association between chromosome 9p21 variants and CAD risk in Hispanics living in Costa Rica. Design: The current study included 1560 incident cases of nonfatal myocardial infarction (MI) and 1751 population-based controls. Three independent single nucleotide polymorphisms (SNPs) at the chromosome 9p21 locus were genotyped. SSB intake was assessed with the use of a food-frequency questionnaire and was defined as the frequency of intake of daily servings of sweetened beverages and fruit juice. Results: We showed a significant interaction between SSB intake and one of the 3 variants (i. e., rs4977574) on MI risk. The per-risk allele OR (95% CI) of rs4977574 for MI was 1.44 (1.19, 1.74) in participants with higher SSB consumption (>2 servings/d), 1.21 (1.00, 1.47) in those with average consumption (1-2 servings/d), and 0.97 (0.81, 1.16) in subjects with lower consumption (<1 serving/d; P-interaction = 0.005). A genetic risk score derived from the sum of risk alleles of the 3 SNPs also showed a significant interaction with SSB intake on MI risk (P-interaction = 0.03). Conclusion: Our data suggest that unhealthy dietary habits such as higher intake of SSBs could exacerbate the effects of chromosome 9p21 variants on CAD.