Assessment of heart rate variability in elderly patients with type 2 diabetes mellitus

Objective: Cardiac autonomic neuropathy (CAN) is a prevalent complication of type 2 diabetes mellitus (DM) and is associated with elevated cardiovascular risk. The objective of this study was to evaluate changes in heart rate variability (HRV) in elderly patients with type 2 DM and to investigate its relationship with laboratory findings. Patients and Methods: The present retrospective study comprised 182 subjects aged >= 65 years who underwent 24-hour Holter ECG monitoring. Patients were divided into two groups: a DM group (n=72) and a control group (n=110). HRV parameters in both time and frequency domains were analyzed, and their correlations with laboratory markers were evaluated. Results: Heart rate variability parameters, including standard deviation of SDNN (p=0.004), SDANN (p=0.008) and SDNN index (p=0.015), were found to be significantly lower in DM. Furthermore, a decline in frequency domain parameters, including POWER (p=0.004), VLF (p=0.006), LF (p =0.007) and HF (p=0.049), was observed. In addition, a negative correlation was identified between HRV and inflammatory markers, such as white blood cell (WBC) count (p <0.001). Conclusion: Reduced HRV in elderly diabetic patients suggests autonomic dysfunction and increased cardiovascular risk. The inverse correlation between HRV and inflammatory markers highlights the potential role of systemic inflammation in autonomic impairment.