Fig. 1

A Body weight, blood glucose and triglycerides in m Lepr^db and Lepr^db mice. B Blood lactic acid in Lepr^db vs. m Lepr^db mice and T2DM vs. non-T2DM. C Pulsed‐wave Doppler showing diastolic function: peak velocity of the E wave and A wave, E/A ratio in Lepr^db vs. m Lepr^db mice. D HE and Masson staining of the heart in Lepr^db vs. m Lepr^db mice. E Volcano plot showing differentially expressed genes (DEGs) of Lepr^db vs. m Lepr^db mice. F GO and KEGG analysis. G Protein–protein interaction (PPI) hub networks of Slc16a3. H MCT4 immunohistochemical staining of heart tissue in Lepr^db vs. m Lepr^db mice. I Cardiac Mct1, 3, 4 mRNA expression in Lepr^db vs. m Lepr^db mice. J Western blot analysis and quantification of MCT4, MCT1, and MCT4:MCT1 ratio in Lepr^db vs. m Lepr^db mice