Influence of autonomic neuropathy upon left ventricular dysfunction in insulin-dependent diabetic patients.
BACKGROUND
Diabetic cardiomyopathy is a well-defined complication of diabetes that occurs in the absence of ischemic, vascular, and hypertensive disease.


OBJECTIVE
The study was undertaken to test the relationship among autonomic neuropathy (AN), 24-h blood pressure (BP) profile, and left ventricular function.


METHODS
Nineteen type-1 diabetic patients underwent autonomic tests and echocardiographic examination. Patients were divided according to the presence (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 and 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 E/A 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 diastolic interventricular septum thickness (r 0.57; p = 0.01), sleep systolic BP (r 0.45; p = 0.05), sleep diastolic BP (r 0.54; p = 0.02), and correlated inversely 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 correlated between themselves (r - 0.6; p = 0.005).


CONCLUSIONS
Our results suggest that left ventricular diastolic dysfunction may be detected very early in type-1 diabetic patients with AN. Parasympathetic lesion and nocturnal elevations in BP could be the link between AN and diastolic ventricular dysfunction.
Monteagudo
P T
PT
Department of Medicine, Escola Paulista de Medicina, UNIFESP, São Paulo, Brazil.
Moisés
V A
VA
Kohlmann
O
O
Ribeiro
A B
AB
Lima
V C
VC
Zanella
M T
MT
D000328:Adult; D000704:Analysis of Variance; D001342:Autonomic Nervous System Diseases / Q000150:complications* / Q000175:diagnosis; D001795:Blood Pressure Determination; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000175:diagnosis; D003929:Diabetic Neuropathies / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006321:Heart / Q000294:innervation*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology*