TCF7L2 and type 2 diabetes mellitus: However, when read with previous studies that have suggested that postprandial lipemia is an early phenomenon in diabetes, prediabetes (27), first degree relatives of T2DM (24, 27) as well as our previous study in animals (28), it would appear likely that it is TCF7L2 gene associated PPHTg that results in insulin resistance and not vice versa.