Abstract
AimsPresent 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.MethodsConsecutive 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.ResultsHRR 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.ConclusionsPresent 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.
Highlights
The prevalence of type 2 diabetes mellitus (DM) is increasing constantly worldwide [1]
The results showed that both of MSNA and insulin resistance index were significantly decreased after 12 weeks pioglitazone therapy, suggesting that improved insulin resistance with pioglitazone could result in the inhibition of sympathetic nerve activity in DM patients with recent myocardial infarction
There was no significant difference on gender, age, body mass index, incidence of current smoker, coronary artery disease (CAD), hypertension, dyslipidemia and betablockers use, resting heart rate, peak heart rate, creatinine, cardiac troponin I, N-terminal pro-brain natriuretic peptide (NT-proBNP) among the three groups
Summary
The prevalence of type 2 diabetes mellitus (DM) is increasing constantly worldwide [1]. CAN was traditionally evaluated by five autonomic reflex tests as described by Ewing in 1985, including: the heart rate responses to the Valsalva maneuver, standing up (30:15 ratio), and deep breathing (maximum-minimum heart rate); the blood pressure responses to standing up (postural blood pressure change), and sustained handgrip [6]. These tests are complex and require the active collaboration of patients, which limits the widespread use of this method in the daily clinical practice. Cardiac sympathetic function could be assessed by scintigraphy with 123I-metaiodobenzylguanidine cardiac-scintigraphy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
