TREH and type 2 diabetes mellitus: However, in the present study we did not find that plasma trehalase activity measured at a non-diabetic stage directly predicts the development of T2D in Pima Indians, although our sample size for this analysis (n = 320) may have low statistical power to detect a modest predictive effect of trehalase activity on T2D as indicated by the confidence interval of the hazard ratio (95 % CI 0.81–1.07).