Relationship between changes in heart rate variability indices and blood glucose control in Type 2 Diabetes Mellitus

Resumen

Diabetes mellitus (DM) is one of the mostcommon health problems in the community.DM is associated with pathologicchanges in the cardiovascular system due to alterations inthe autonomic nervous system (ANS). Dysfunction of thecardiovascular ANS can lead to fatal arrhythmias and suddendeath. The aim of this study was to investigate the relationshipbetween changes in heart rate variability (HRV)indices and blood glucose control status in patients withtype 2 DM. Patients with type 2 DM who presented toour university Diabetes Clinic were eligible to be included.Fasting blood glucose (FBG), 2-hour postprandial bloodglucose test (2PPG), and hemoglobin A1C (HbA1C) weremeasured. According to the HbA1C the patients werecategorized as euglycemia (HbA1C <7%) and poorly controlledDM (HbA1C >7%). HRV indices were determinedby 24-hour Holter monitoring. There were 41 patientswith euglycemia and 39 patients whose blood glucosewas poorly controlled. pNN, SDANN, and SDNN indiceswere significantly higher in the euglycemia group thanin the group with poorly controlled glucose. There wassignificant and inverse correlation between pNN, SDANN,and SDNN with serum levels of HBA1C. However, no significantcorrelation was observed between FBS and 2PPGwith HRV indices. HRV indices were significantly lowerin diabetic patients with poorly controlled blood glucosewhen compared to diabetics with good control of bloodglucose. These findings reflect dysfunction of the ANS inpatents with poorly controlled blood glucose.