MSTN and type 1 diabetes mellitus: Further, compared to T1D Myo KO mice, the T1D WT mice had elevated fasting glucose (Figure 1C) and impaired glucose clearance, as demonstrated by an intraperitoneal glucose tolerance test (IGTT) in Figure 1E. Myostatin deletion decreased the area under the curve of the IGTT to levels of control (Figure 1F).