Interactions between genetic variants associated with adiposity traits and soft drinks in relation to longitudinal changes in body weight and waist circumference

Background: Intake of sugar-sweetened beverages is associated with obesity, and this association may be modified by a genetic predisposition to obesity. Objective: We examined the interactions between a molecular genetic predisposition to various aspects of obesity and the consumption of soft drinks, which are a major part of sugar-sweetened beverages, in relation to changes in adiposity measures. Design: A total of 4765 individuals were included in the study. On the basis of 50 obesity-associated single nucleotide polymorphisms that are associated with body mass index (BMI), waist circumference (WC), or the waist-to-hip ratio adjusted for BMI (WHRBMI), the following 4 genetic predisposition scores (GRSs) were constructed: a complete genetic predisposition score including all 50 single nucleotide polymorphisms (GRS(complete)), a genetic predisposition score including BMI-associated single nucleotide polymorphisms (GRS(BMI)), a genetic predisposition score including waist circumference associated single nucleotide polymorphisms (GRS(WC)), and a genetic predisposition score including the waist-to-hip ratio adjusted for BMI associated single nucleotide polymorphisms (GRS(WHR)). Associations between soft drink intake and the annual change (A) in body weight (BW), WC, or waist circumference adjusted for BMI (WCBMI) and possible interactions with the GRSs were examined with the use of linear regression analyses and meta-analyses. Results: For each soft drink serving per day, soft drink consumption was significantly associated with a higher Delta BW of 0.07 kg/y (95% CI: 0.01, 0.13 kg/y; P = 0.020) but not with the Delta WC or Delta WCBMI. In analyses of the Delta BW, we showed an interaction only with the GRS(WC) (per risk allele for each soft drink serving per day: -0.06 kg/y; 95% CI: -0.10, -0.02 kg/y; P = 0.006). In analyses of the Delta WC, we showed interactions only with the GRS(BMI) and GRS(Complete) [per risk allele for each soft drink serving per day: 0.05 cm/y (95% CI: 0.02, 0.09 cm/y; P = 0.001) and 0.05 cm/y (95% CI: 0.02, 0.07 cm/y; P = 0.001), respectively]. Nearly identical results were observed in analyses of the Delta WCBMI. Conclusions: A genetic predisposition to a high WC may attenuate the association between soft drink intake and BW gain. A genetic predisposition to high BMI as well as a genetic predisposition to high BMI, WC, and WHRBMI combined may strengthen the association between soft drink intake and WC gain. However, the public health impact may be limited.