Risk of Metabolic and Cardiovascular Risk Factors in Individuals with Autonomic Imbalance Measured by Heart Rate Variability

Background: Studies have reported that reduced autonomic nervous system activity could result in a suboptimal health condition and various diseases, further increasing the mortality rate. The present study aimed to determine the difference in risk factors for metabolic and cardiovascular diseases in patients with reduced or unstable autonomic activity according to heart rate variability test results.Methods: We recorded blood pressure, physical measurements (body mass index and waist circumference), fasting blood glucose, and blood lipid status. Indicators representative of autonomic nerve functionality (total power [TP], standard deviation of the normal-to-normal intervals [SDNN], low-frequency band [LF], high-frequency band [HF]) were measured using a 5-minute heart rate variability test. Each indicator was divided into quartiles.Results: In men, the risk of abdominal obesity was high in the group with a low TP. In the group with a low SDNN, TP, and LF, the risk of a blood pressure increase was high. When LH and HF were low, there was a high risk of increased fasting blood sugar, whereas when LH was low, there was a high risk of hypertriglyceridemia. Women with SDNN loss had higher odds ratios for abdominal obesity and low high-density lipoprotein cholesterolemia.Conclusions: These results indicate a higher risk of having risk factors for metabolic and cardiovascular diseases, such as abdominal obesity, elevated blood pressure, hyperglycemia, hypertriglyceridemia, and low high-density lipoprotein cholesterolemia in a group with reduced autonomic activity measured by heart rate variability. Women with a low SDNN had a 4.51-fold higher risk of abdominal obesity than women with a high SDNN, showing the greatest value of the heart rate variability indices.