Metformin improves lipid metabolism disorders through reducing the expression of microsomal triglyceride transfer protein in OLETF rats.

•Type 2 diabetes mellitus are associated with lipid metabolism disorders which the pathogenic mechanism is not clear.•In this study, increased expression of microsomal triglyceride transfer protein (MTP) was found in the liver of Otsuka Long Evans Tokushima Fatty (OLETF) rats.•It suggested that MTP might be associated with the lipid metabolism disorder in OLETF rats.•Metformin, as the first-line medication for the treatment of type 2 diabetes, could improve lipid metabolism through reducing the expression of MTP.