A study involving 1,818 Hispanic Americans has confirmed that diabetes, whether controlled or not, is linked to worse measures of cardiac structure and function, and also shows that this happens very early in the development of diabetes.
Demmer, R. T., Allison, M. A., Cai, J., Kaplan, R. C., Desai, A. A., Hurwitz, B. E., … Rodriguez, C. J. (2016). Association of Impaired Glucose Regulation and Insulin Resistance With Cardiac Structure and Function. Circulation: Cardiovascular Imaging, 9(10), e005032. https://doi.org/10.1161/CIRCIMAGING.116.005032