A meta-analysis of gene (5-HTT) × environment interactions in eating pathology using secondary data analyses

Background Gene × environment (G × E) interactions in eating pathology have been increasingly investigated, however studies have been limited by sample size due to the difficulty of obtaining genetic data. Objective To synthesize existing G × E research in the eating disorders (ED) field and provide a clear picture of the current state of knowledge with analyses of larger samples. Method Complete data from seven studies investigating community ( n  = 1750, 64.5% female) and clinical ( n  = 426, 100% female) populations, identified via systematic review, were included. Data were combined to perform five analyses: 5-HTTLPR × Traumatic Life Events (0–17 events) to predict ED status ( n  = 909), 5-HTTLPR × Sexual and Physical Abuse ( n  = 1097) to predict bulimic symptoms, 5-HTLPR × Depression to predict bulimic symptoms ( n  = 1256), and 5-HTTLPR × Impulsivity to predict disordered eating ( n  = 1149). Results The low function (s) allele of 5-HTTLPR interacted with number of traumatic life events ( P P Fig. 1 ). No other G × E interactions were significant, possibly due to the medium to low compatibility between datasets ( Fig. 1 ). Conclusion Early promising results suggest that increased knowledge of G × E interactions could be achieved if studies increased uniformity of measuring ED and environmental variables, allowing for continued collaboration to overcome the restrictions of obtaining genetic samples.