Impact of blood glucose control on sympathetic and vagus nerve functional status in patients with type 2 diabetes mellitus

Abstract

Aims Present study observed the impact of blood glucose control on sympathetic and vagus functional status in type 2 diabetes mellitus (DM) patients through observing the association between glycosylated hemoglobin (HbA1c) level and sympathetic and vagus functional status detected by heart rate recovery (HRR) and heart rate variability (HRV) assessments. Methods Consecutive hospitalized DM patients were divided into well glycemic control group (HbA1c < 7.0%, group WGC, n = 100) and poor glycemic control group (HbA1c ≥ 7.0%, group PGC, n = 100), 100 hospitalized patients without DM served as control group (group C). All subjects underwent blood biochemistry test, treadmill exercise testing and 24-h Holter monitoring. Results HRR and HRV parameters were significantly lower in group WGC and PGC than in group C. Standard deviation of NN intervals (SDNN), standard deviation of all 5-min average NN intervals (SDANN), very low frequency (VLF) values were significantly lower in group PGC than in group WGC. HbA1c level was negatively correlated with HRR1, SDNN, SDANN, VLF, low frequency and high frequency. Logistic regression analysis showed that lower SDNN, SDANN and VLF values were risk factors for high HbA1c levels in DM patients after adjusting for gender, age and beta-blocker use in the model 1, and for gender, age, beta-blocker use, coronary artery disease and hypertension in the model 2. Conclusions Present results indicate that sympathetic and vagal functional status are impaired independent of HbA1c level, while poor glycemic control is related to more significant neurocardiac dysfunction in DM patients.

Diabetes and subclinical hypothyroidism on heart rate variability

“…Hb1Ac is a key parameter for monitoring the regulation of diabetes, and for assessing the risk of microvascular complications and cardiovascular diseases in diabetic patients 38 . Although the relationship between cardiac autonomic modulation and HbA1c level in DM patients is not fully understood, Yu et al 39 found that the autonomic function is impaired in DM patients independently of HbA1c levels. Cherkas et al 40 evaluated apparently healthy young adults and found negative correlations of HBA1c (under the conventional threshold) with some HRV markers, including SDNN and LF, after orthostatic test, but not in the supine position.…”

Silencing cyclophilin A improves insulin secretion, reduces cell apoptosis, and alleviates inflammation as well as oxidant stress in high glucose-induced pancreatic β-cells via MAPK/NF-kb signaling pathway

“…glucose control and alimentary control, incapable of radical treatment [33,34]. Finding the endogenous targets that exert substantial roles in the occurrence and development of diabetes mellitus may open up new direction for radical treatment of diabetes mellitus.…”

Effect of Circadian Rhythm - Autonomic Nervous System - Endocrine Hormone Axis on The Occurrence and Development of Diabetes: A Review and Perspective

“…Increased sympathetic nerve function can lead to blood glucose disorders in patients with diabetes, while the concentrations of norepinephrine, epinephrine and cortisol increase in serum and urine. These hormones can promote gluconeogenesis and reduce insulin sensitivity [24][25][26]. When the sympathetic nerve is excited, the release of norepinephrine increases and binds to the receptors on vascular smooth muscle, resulting in peripheral vasoconstriction, decrease of skeletal muscle blood flow, decrease of skeletal muscle glucose uptake and utilization, and decrease of insulin sensitivity [27,28].…”

“…Straznicky and others also found that long-term excessive activation of sympathetic nerves can lead to down-regulation of β-adrenaline metabolic reactivity and insulin resistance, which will further stimulate the activation of sympathetic nerve, thus forming a vicious circle and aggravating insulin resistance [32]. In patients with diabetes, sympathetic function is enhanced and parasympathetic function decreases [26].…”