Autonomic neuropathy tests correlate with left ventricular mass and cardiac diastolic function in normotensive patients with type 2 diabetes mellitus and without left ventricular hypertrophy.

Background: Hypertensive diabetic patients, when compared with essential hypertensive patients, have a higher left ventricular mass index (LVMI) and an impaired cardiac diastolic function (CDF). Autonomic neuropathy (AN) could contribute to this finding.
Objective: To evaluate the relationship between AN tests, and LVMI and CDF in normotensive patients with type 2 diabetes mellitus (DM2) and without AN symptoms or left ventricular hypertrophy.
Methods: In 21 normotensive patients with DM2 (group 1) and 16 control subjects (group 2), LVMI and CDF were evaluated using atrial deceleration time, isovolumic relaxation time, E wave, A wave and E/A wave ratio. AN tests performed included a deep breathing test, Valsalva manoeuvre and lying-to-standing test.
Results: Groups did not differ in clinical and echocardiographic characteristics. None of the patients in either group presented with left ventricular hypertrophy. In group 1, there were correlations between the deep breathing test and LVMI (r=-0.6; P<0.01) and between the deep breathing test and E/A wave ratio (r=0.4; P<0.05). No correlations were found in the control group.
Conclusion: In DM2 patients, AN tests correlated with LVMI and CDF before left ventricular hypertrophy, hypertension, impaired CDF and diabetic AN symptoms were present. The present study suggests that AN tests could be regularly performed in DM2 patients. Any abnormalities in tests should be followed by a cardiac evaluation.