A Study of Pattern and Prevalence of Cardiovascular Autonomic Neuropathy(CAN) in Type 2 Diabetes Mellitus Patients

Abstract

Background: Cardiovascular autonomic neuropathy(CAN) is a common underdiagnosed complication in patientswith type -2 diabetes mellitus in clinical practice. CAN is associated with increased morbidity and mortalityamong diabetics. Only few studies are available in literature about pattern and prevalence of CAN among type-2diabetics in developing countries like India where burden of the disease is high.Aim : To study the pattern and prevalence of CAN in type 2 Diabetes mellitus patients and to study the sympatheticand parasympathetic abnormalities related to cardiovascular system in patients with type 2 Diabetes mellitus.Materials and Methods: The study design was observational Retrospective and was conducted at Department ofPhysiology, Thanjavur Medical college, between april to june 2022. We recruited 80 patients (55 male and 25 female)with type 2 Diabetes mellitus of age 30 years and above from Medicine and Non-Communicable Diseases (NCD)Outpatient Department of Thanjavur Medical college hospital. The study was approved by Institutional Ethicalcommittee(IEC). After getting informed written consent from all the participants, age, duration of diabetes, systolicblood pressure and HbA1c levels were recorded. Patients were made to undergo Autonomic Function Tests(AFT)in Research Laboratory. Assessment of CAN was done retrospectively and scoring was done using three differentscoring system namely Ewing’s, Bellavere’s and AIIMS criterias.Statistical Analysis and Results: Mean age was 48.86(±5.694) years and duration of diabetes was 108.48(±25.039)months. Mean systolic blood pressure(SBP) was 132.10(±25.039)mmHg and HbA1c level was 8.63(±0.46368).Statistical Analysis was done using unpaired ‘T’ and Chi-Square tests. The abnormality of single autonomic testranged from 6% in valsalva ratio to 46.25% in cold pressor test. CAN was found in 14 and 20 patients by Ewings’sand Bellavere’s criteria respectively. AIIMS criteria revealed 43 patients with isolated sympathetic abnormalityand 37with parasympathetic abnormality and 25 with both abnormalities. Duration of diabetes, systolic bloodpressure(SBP) and and HbA1c levels were not significantly correlated with autonomic abnormality in our study.Only Valasava Ratio(VR) correlates with autonomic abnormality significantly(P value<0.05).Conclusion: CAN is a common microvascular abnormality in type 2 diabetes mellitus. We have to highlight theimportance of regular testing of autonomic functions in type 2 diabetes mellitus to prevent mortality due tocardiovascular complications.