Heart Rate Variability as a Potential Non-invasive Marker of Blood Glucose Level

Currently, monitoring of blood glucose level (BGL) is constrained by the invasive nature of BGL measures. We investigated heart rate variability (HRV) parameters as potential non-invasive markers of BGL. Healthy volunteers (n = 25; aged 27 ± 9 years) uninhibited by regular medications or chronic illness were recruited for this study. BGL and HRV were assessed during fasting (9:00 am), postprandial (12:00 pm), and postabsorptive (3:00 pm) periods using self-monitoring of blood glucose techniques and ten-minute electrocardiogram, respectively. Frequency-domain HRV measures, which estimate contributions of sympathetic and parasympathetic systems to autonomic modulation of the heart, were correlated against BGL data with the following significant (p < 0.05) findings. The change in BGL from fasting to postprandial levels was negatively correlated with fasting low frequency (LF) power and total power (TP). Postprandial BGL was negatively associated with fasting LF and TP, as well as with postprandial LF, high frequency (HF), and TP. The change in BGL from postprandial to postabsorptive levels was positively correlated with fasting LF power, as well as with postprandial LF, HF, and TP. Frequency-domain HRV parameters may be useful in predicting the magnitude and direction of acute fluctuations in BGL, and further research could develop them as non-invasive markers of BGL.