Abstract P223: Starch Digestion Related Amylase Genotypes Affect 2-year Adiposity Changes in Response to Weight-loss Diets: The Pounds Lost Trial
Background/Aim: Salivary amylase, which is encoded by the salivary gene (AMY1), is responsible for digesting starchy foods into sugar, and the AMY1 shows extensive copy number variations which directly affect differences in salivary and serum amylase amount and activity. Recent evidence suggests associations of low serum amylase levels and obesity. We investigated whether the copy number related AMY1 genotypes were associated with 2-year changes of adiposity in response to weight-loss diet intervention.
Methods: This study included 692 obese individuals with data on AMY1 variant rs11185098 who were randomly assigned to 1 of 4 diets varying in macronutrient contents. Changes of body weight (BW) and waist circumference (WC) over 2 years during the intervention were evaluated according to the genotype.
Results: We found that changes in BW and WC were significantly different according to the AMY1 genotype (Figure). After adjustment for age, sex, ethnicity, diet groups and value for the respective outcome traits at baseline, carrying the minor A allele (which indicates higher amylase amount and activity-associated allele) of rs11185098 was significantly associated with greater reduction of BW at 6, 12, 18, and 24 months (β (SE), p value; -0.7 (0.35), 0.04; -1.21 (0.46), 0.009; -1.63 (0.52), 0.0017; -1.27 (0.49), 0.0095, respectively). Also, increasing number of allele A was associated with a greater decrease of WC at 6, 12, 18 and 24 months (p <0.05 for all). The genetic effects on these outcomes did not significantly differ across the diet groups.
Conclusions: Our study indicated that the genetic variant responsible for starch metabolism significantly influenced on the response to weight-loss dietary intervention. Obese individuals carrying the AMY1 genotype that associated with higher salivary amylase activity may benefit from greater weight loss and the improvement of central adiposity in response to low-calorie diet interventions.
Author Disclosures: Y. Heianza: None. D. Sun: None. T. Wang: None. G.A. Bray: None. F.M. Sacks: None. L. Qi: None.
- © 2017 by American Heart Association, Inc.