Abstract 1701: Cardiac Autonomic Neuropathy and Left Ventricular Function in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Intervention and Complications Study (DCCT/EDIC)
Objective: In type 1 diabetes (T1DM), left ventricle (LV) dysfunction often precedes or occurs in the absence of significant coronary artery disease or hypertension. The presence of cardiac autonomic neuropathy (CAN) may contribute to or be associated with LV dysfunction. We therefore sought to determine the association between CAN and indices of LV function as assessed by cardiac magnetic resonance imaging (CMRI) in the DCCT/EDIC cohort.
Methods: Measures of CAN (R-R response to paced breathing, Valsalva ratio, and blood pressure response to standing) were obtained during the 13th or 14th year of EDIC follow-up. Indices of LV function: cardiac output (Q), end diastolic volume (EDV), end systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and left ventricular end diastolic mass (EDM) were obtained by cardiac MRI studies done during the 14th or 15th year of EDIC. Each of the six CMRI outcomes was compared separately to R-R variation < 15, Valsalva ratio < 1.5, and CAN (defined as either R-R < 15, or R-R < 19 and a Valsalva < 1.5 and/or a drop > 10 mmHg in postural BP) using analysis of covariance models, and adjusting for concurrent age, sex, blood pressure, and heart rate. Analyses were performed in N = 911 participants with valid CAN and CMRI tests after excluding those with evidence of ischemic heart disease (N = 63).
Results: Abnormal R-R variation was associated with increased cardiac output (3.16 L/min/m2 vs. 2.98; P = 0.0056) and left ventricular end diastolic mass (75.20 g/m2 vs. 70.68; P = 0.0008). Abnormal Valsalva ratio was associated with decreased end diastolic volume (67.63 ml/m2 vs. 70.17; P = 0.0266) and end systolic volume (25.29 ml/m2 vs. 27.06; P = 0.0118). Finally, abnormal CAN function was associated with increased cardiac output (3.16 L/min/m2 vs. 2.96; P = 0.0012) and left ventricular end diastolic mass (74.51 g/m2 vs. 70.69; P = 0.0026).
Conclusion: These data suggest that CAN is associated with increased LV mass and higher cardiac output assessed by CMRI independent of age, sex and other factors. The significance of these findings remains to be determined by future studies.