European Journal of Biomedical and Pharmaceutical Sciences

PREVALENCE OF CARDIAC AUTONOMIC NEUROPATHY (CAN) IN PATIENTS OF TYPE 2 DIABETES MELLITUS (T2DM) – A STUDY FROM EASTERN INDIA.

*Dr. Sumit Kumar Chakrabarti, Atindra Nath Bandopadhyay and Pradip Kumar Datta

ABSTRACT

Background: Presence of symptoms along with abnormal cardiovascular function tests suggest poor prognosis with increased incidence of silent myocardial infarction & sudden cardiac death. The present study was undertaken to highlight the magnitude of the problem in Eastern India.Materials and Methods: Total 80 male and female subjects suffering from type 2 diabetes mellitus (T2DM) were selected. The battery of autonomic cardiovascular tests performed as bed side procedure included tests reflecting cardiac parasympathetic damage, heart rate response to deep breathing, heart rate response to standing. Tests reflecting sympathetic damage conducted were blood pressure (BP) response to standing, BP response to sustained hand grip. Other routine investigations performed included complete hemogram, serum urea, creatinine, Na, K, lipid profile, liver function test, urine analysis and albumin creatinine ratio, USG abdomen, chest x ray and echocardiography. Results: Cardiac Autonomic Neuropathy (CAN) was found in 50% of study subjects. Of those detected with CAN, Parasympathetic neuropathy was found in 50% cases and sympathetic neuropathy in 23.75% cases. Symptoms of CAN were less commonly encountered. Dizziness on standing was encountered in 37.5% patients. Bladder symptoms, abnormal sweating and diarrhea were other symptoms commonly encountered. With increasing duration of diabetes, HRV on standing doubled in group B (5 – 10 years duration) but unaltered in group C (>10 years duration) compared with group A (diabetes duration less than 5 years). The most significant abnormality was HRV with breathing which was absent in group and appeared in group B and significant in group C for BP response to standing but not for BP response to isometric hand grip. Very significant changes in HDL data was found between group A and C with which there was also significant change between group A and C in HRV breathing, BP response to standing and isometric hand grip. Retinopathy was detected, both non proliferative and proliferative in 10% of T2DM patients in the present study. Conclusion: CAN is detected by different cardiac autonomic function tests. Parasympathetic dysfunction is early to appear but does not increase linearly with duration. Sympathetic dysfunction appears late and expresses a partial liner increase. CAN symptoms are not as sensitive as autonomic function test to detect cardiac neuropathy. Assessment of autonomic cardiovascular reflexes affords a satisfactory method of evaluation of CAN. Parasympathetic cardiac autonomic function test are more sensitive for the detection of CAN than sympathetic test. HRV deep breathing is the most sensitive parasympathetic abnormality detection test, followed by HRV standing and HRV valsalva maneuver. BP response to postural hypotension is slightly more sensitive than that of BP response to isometric hand grip.

Keywords: Cardiac Autonomic Neuropathy, Type 2 diabetes mellitus, India, Prevalence.