Assessment of Diabetics with Various Degrees of Autonomic Neuropathy Using Power Spectral Analysis

In this study, we investigate the feasibility of using power spectral density (PSD) analysis to assess the healthy subjects and diabetics with mild, moderate and severe autonomic neuropathy. Continuous cerebral blood flow velocity (CBFV) was measured using transcranial Doppler ultrasound (TCD), and continuous arterial blood pressure (ABP) was measured using Finapres device under supine and hyperventilation conditions. Four groups of subjects were recruited in this study including 11 healthy adults (56.4±8.1 years), 15 diabetics with mild autonomic neuropathy (50.8±15.7 years), 21 diabetics with moderate autonomic neuropathy (61.8±9.0 years), and 25 diabetics with severe autonomic neuropathy (61.4±10.0 years). According to the results of PSD, it can be speculated that while the diabetic autonomic neuropathy of a patient becomes more serious, the function of cerebral auto regulation (CA) tends to be more imbalance. In conclusion, sympathetic activity was different on diabetics with autonomic neuropathy from supine to hyperventilation by the analysis of power spectrum. Sympathetic activity was increased to reduce CBFV from supine to hyperventilation. Due to hyperventilation make oxygen increase in the brain, cerebral auto regulation can make sympathetic activity increased. Therefore, power spectral analysis can be a useful tool to investigate autonomic neuropathy in diabetics.