Objective To explore the influence of family history of diabetes and central obesity on prediabetes(Pre-DM)and their interaction.Methods Based on the REACTION studyduring August December 2011 in Dalian,2587 individuals aged≥40 with normal blood glucose(BG)were divided into newly diagnosed Pre-DM(n=522)and BG normal group(NC,n=2065)during follow-up.The influence of family history of DM and central obesity on prediabetes and their interaction were analyzed.Results The age,SBP,DBP,BMI,WC,HDL-C,LDL-C,TG,ALT,GGT,FPG,2 hPG,HbA1c,FIns,HOMA-IR,SUA and the incidence of hypertension,fatty liver disease,dyslipidemia,overweight/obesity and central obesity in Pre-DM group were all higher than those in NC group(P＜0.05).Multivariate logistic regression analysis showed that family history of diabetes and central obesity were risk factors for Pre-DM.After adjustment,no significant multiplicative interaction was shown between diabetes family history and central obesity on the risk of Pre-DM(P=0.764).Quantitative analysis of interaction showed that RERI=0.110,S=1.112 and AP=0.053,suggesting that DM family history and central obesity have no significant additive interaction on the risk of Pre-DM.Conclusion The family history of DM and central obesity are both associated with the occurrence of Pre-DM,but there is no significant interaction.