GDF15 and cardiomyopathy: Changes in cardiac function (mitral isovolumic systolic time, systolic time, and isovolumic diastolic time values, all of which reflect diastolic function, were statistically significant compared with controls) as reflected by tissue doppler imaging were correlated with GDF-15 in a follow-up study of cardiomyopathy in patients with type 1 diabetes [56].