Abstract 21: Accounting For Smoking Behavior In Genome-wide Analysis Of Obesity Phenotypes: The Giant (genetic Investigation Of Anthropometric Traits) Consortium

Obesity, especially central obesity, and cigarette smoking (SMK) are both important risk factors for cardiovascular disease (CVD). Yet, smokers often exhibit lower body mass index (BMI) and higher waist circumference (WC) compared to non-smokers; also, smoking cessation leads to weight gain. Genome-wide association (GWA) studies have identified genetic loci that are associated with risk of overall and central obesity; yet little is known about whether and how SMK influences the genetic susceptibility to obesity. This study aims to discover genetic loci that are associated with obesity, measured as BMI and WC adjusted for BMI (WCa), and where the effects are hidden by SMK. We used results from 42 studies including up to 126,767 subjects with GWA data available through the GIANT Consortium. Each study employed three association models while considering smoking status (current vs. not current smokers): 1) SNP effects adjusted for SMK (SNPadjSmk), 2) SNP by SMK interaction effects (SNPxSMK), and 3) joint effe...