Influence of autonomic neuropathy upon left ventricular dysfunction in insulin-dependent diabetic patients

Background: Diabetic cardiomyopathy is a well-defined complication of diabe tes that occurs in the absence of ischemic, vascular, and hypertensive dise ase. Hypothesis: The study was undertaken to test the relationship among autonom ic neuropathy (AN), 24-h blood pressure (BP) profile, and left ventricular function. Methods: Nineteen type-1 diabetic patients underwent autonomic tests and ec hocardiographic examination. Patients were divided according to the presenc e (AN+) or absence (AN-) of AN. Results: In the AN+ group (n = 8), the E/A ratio at echo was lower than in the AN- group (n = 11) (1.1 +/- 0.3 vs. 1.6 +/- 0.3; p < 0.005). Systolic a nd diastolic BP reductions during sleep were smaller in the AN+ than in the AN- group (6.6 +/- 6.6 vs. 13.0 +/- 4.3%; p < 0.03 for systolic and 12.8 /- 6.8 vs. 20.0 +/- 4.0% for diastolic BP reduction; p < 0.03, respectively ). Considering all patients, the EIA ratio correlated inversely with awake diastolic BP (r - 0.63; p = 0.005); sleep systolic BP (r - 0.48; p = 0.04), and sleep diastolic BP (r - 0.67; p = 0.002). The AN correlated with diast olic interventricular septum thickness (r 0.57; p = 0.01), sleep systolic B P (r 0.45; = 0.05), sleep diastolic BP (r 0.54; p = 0.02), and correlated i nversely with systolic and diastolic sleep BP reduction (r - 0.49; p = 0.03 and r - 0.67; p = 0.002, respectively). Finally, E/A ratio and AN score co rrelated between themselves (r - 0.6; p = 0.005). Conclusion: Our results suggest that left ventricular diastolic dysfunction may be detected very early in type-1 diabetic patients with AN. Parasympat hetic lesion and nocturnal elevations in BP could be the Link between AN an d diastolic ventricular dysfunction.