Although pediatric cardiomyopathy is rare, the condition is severe and life-threatening. The main focus of this proposed study will examine whether insulin resistance is correlated with decreased cardiac function which will hopefully pave the way for future clinical trials using medications that sensitize insulin such as metformin or glucagon-like peptide-1 (GLP-1 agonists) as possible therapeutic agents. The exploratory piece of this study will investigate a novel therapeutic target by determining whether FGF21 has any direct effects on cardiac function and whether it interacts with insulin resistance in altering cardiac function. Patients with cardiomyopathy normally undergo ECHO as part of routine evaluation and follow up and is standard of care. At this time, there are no official guidelines for pediatric patients with cardiomyopathy to undergo oral glucose tolerance testing (OGTT) and thus it is not part of the standard of care. Based on findings from this study, the investigators hope to justify performing an OGTT on pediatric patients with dilated or hypertrophic cardiomyopathy and incorporate the procedure in future practice guidelines.
This study will investigate whether there is an association between insulin resistance and cardiac function in children with dilated or hypertrophic cardiomyopathy. This study will also investigate whether there is an association between FGF21 and cardiac function in children with dilated or hypertrophic cardiomyopathy and whether this is mediated through greater insulin resistance and/or through independent effects.