Aims: The Aim of the present study was to examine whether there is a relationship between autonomic nervous system function and glycemic variability (GV) in patients with type 2 diabetes (T2D).
Methods: A total of 50 (29 males) patients with T2D (mean age 58.4 ± 9.9 years, median diabetes duration 5.5 [IQR 2.0-9.25] years), on oral antidiabetic agents, underwent ECG recording and subcutaneous glucose monitoring, simultaneously and continuously, for 24 hours.
Results: After adjustment for HbA1c and diabetes duration, total power of heart rate variability (HRV) was inversely associated with the standard deviation of the mean interstitial tissue glucose (MITG) and with the M-value during the entire recording (r: -0.29, P = 0.052; r: -0.30, P = 0.047, resp.) and during the night (r: -0.29, P = 0.047; r: -0.31, P = 0.03, resp.). Most of the HRV time-domain indices were significantly correlated with standard deviation of the MITG and the M-value. These correlations were stronger for the HRV recordings during the night. No significant association was found between HRV parameters and MAGE.
Conclusions: HRV is inversely associated with GV in patients with T2D, which might be a sign of causation between GV and autonomic dysfunction. Prospective studies are needed to further investigate the importance of GV in the pathogenesis of long-term complications of diabetes.