Clinical assessment of the autonomic nervous system in diabetes mellitus and its correlation with glycemic control

AIM: Clinical assessment of the autonomic nervous system in Diabetes mellitus (DM) and its correlation with glycemic control. STUDY DESIGN: Cross sectional study of 50 adult diabetes patients. MATERIALS AND METHODS: Fifty patients with DM who were on regular treatment with either insulin and/or oral hypoglycemic agents were studied. Cardiovascular autonomic neuropathy (CAN) score was calculated using the clinical test variables. RESULTS: Of the 50 patients 30 had no CAN, 10 had early CAN and 10 had severe CAN. The mean of CAN score increased with duration of diabetes. The mean HbA(1C) was 7.73. The mean CAN score was higher in patients who had complication of diabetes as compared to patients without complications. The heart rate variability with respiration was found to be 15.84 ± 7.02/min. The mean valsalva ratio was 1.31 ± 0.23. The mean drop in BP on standing was 7.30 ± 7.24 mmHg. The mean 30:15 ratio was 1.06 ± 0.04. The mean rise in diastolic BP on sustained hand grip was 16.04 ± 4.11 mmHg. CONCLUSIONS: The prevalence of autonomic neuropathy in DM as assessed by CAN score was 40%. The CAN score did not correlate with the duration of DM. The HbA(1C) had a significant correlation with the severity of autonomic neuropathy. Occurrence of CAN correlated with the presence of peripheral neuropathy but not with the presence of retinopathy or nephropathy. All individual tests in the battery of CAN score were significantly associated with the presence of autonomic neuropathy, except 30:15 ratio.