Comparative Evaluation of Autonomic Function Tests in Type 2 Diabetes Mellitus and Hypertension: Insights from Central India
Background: Type 2 Diabetes Mellitus (T2DM) and hypertension are highly prevalent metabolic disorders that frequently coexist, sharing pathophysiological mechanisms such as insulin resistance, oxidative stress, and endothelial dysfunction. These alterations contribute to autonomic imbalance, an early yet underdiagnosed predictor of cardiovascular morbidity.Objectives: To assess and compare autonomic function among patients with T2DM, hypertension, comorbid disease, and healthy controls using standardized Autonomic Function Tests (AFTs), and to identify metabolic and hemodynamic predictors of autonomic dysfunction. Methods: A case–control study was conducted on 200 participants (aged 35–65 years) divided into four equal groups: T2DM, hypertension, comorbid, and controls. AFTs including E:I ratio, 30:15 ratio, Valsalva ratio, blood pressure response to standing, and handgrip test were performed as per Ewing’s protocol. Biochemical parameters such as HbA1c and blood pressure were recorded. Statistical analysis was done using ANOVA, Pearson’s correlation, and multiple regression (SPSS v26.0). Results: Comorbid participants exhibited the most pronounced autonomic dysfunction with significantly reduced E:I (1.12 ± 0.09) and 30:15 ratios (p < 0.001). HbA1c and systolic BP correlated inversely with parasympathetic indices (r = –0.61 and –0.33, respectively). Regression analysis identified HbA1c (β = –0.42, p = 0.002) and systolic BP (β = –0.33, p = 0.004) as independent predictors of dysfunction. Conclusion: Autonomic dysfunction occurs early in metabolic disorders and intensifies when diabetes and hypertension coexist. Routine use of AFTs can facilitate early detection of subclinical neuropathy, enabling timely interventions to reduce cardiovascular risk, especially in resource-limited settings.