Volume: 46 Issue: 1
Year: 2026, Page: 57-61, Doi: https://doi.org/10.51248/v46i1.232
Received: Dec. 23, 2025 Accepted: Feb. 26, 2026 Published: March 6, 2026
Background: Cardiac autonomic neuropathy (CAN) is a clinically significant yet frequently underrecognized complication of type 2 diabetes mellitus (T2DM). Heart rate variability (HRV) analysis provides a non-invasive method for evaluating cardiac autonomic function. This study aimed to assess time-domain HRV parameters in asymptomatic patients with T2DM compared to healthy controls. Methods: In this hospital-based case-control study, 50 patients with T2DM and 50 age-matched healthy controls (40–60 years) were enrolled following institutional ethics approval. Short-term (5-minute) ECG recordings were obtained under standardized conditions. Time-domain HRV indices - mean RR interval, heart rate, SDNN, RMSSD, pNN50%, RRΔ index, and TINN were analyzed. Group comparisons were performed using independent samples t-test. Effect sizes (Cohen’s d) and 95% confidence intervals (CIs) were calculated, and Bonferroni correction was applied for multiple comparisons. Results: Compared with controls, patients with T2DM exhibited significantly reduced SDNN (mean difference −6.60 ms; 95% CI: −10.4 to −2.8), RMSSD (−10.39 ms; 95% CI: −15.6 to −5.1), pNN50% (−4.69%; 95% CI: −5.6 to −3.7), and TINN (−155.1 ms; 95% CI: −210.4 to −99.8) (adjusted p < 0.01). The T2DM group also demonstrated a lower mean RR interval and higher resting heart rate. Effect sizes ranged from moderate to large (Cohen’s d = 0.6–1.1). Conclusion: Time-domain HRV parameters were significantly reduced in asymptomatic individuals with T2DM, suggesting early subclinical cardiac autonomic dysfunction. Short-term HRV assessment may serve as a practical screening tool for early detection of CAN.
Keywords: Heart rate variability, Type 2 diabetes mellitus, Cardiac autonomic neuropathy, Time-domain analysis.
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Nabeel Beeran Abdul Rahiman, Ahrsia VF, Nasmeen Beeran. Assessment of Cardiac Autonomic Neuropathy Using Time-Domain HRV: A Case-Control Study in Type 2 Diabetes. Biomedicine: 2026, 46(1): 57-61