According to study results published in Diabetes Care, hyperglycemia, obesity, and hypertriglyceridemia in type 2 diabetes (T2D) are negatively related to indices of cardiovascular autonomic neuropathy, although effects were shown to diminish over time.
Cardiovascular autonomic neuropathy (CAN) is a common complication of diabetes and is known to be associated with increased mortality and morbidity. Researchers sought to examine the course of CAN and related cardiometabolic risk factors in patients with T2D.
Risk factors for CAN were assessed as part of the Danish arm of the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care. Data was collected from 777 patients (mean age, 65.0) at 6-year follow-up examinations and 443 patients (mean age, 70.3) at 13-year follow-up examinations. Cardiovascular autonomic reflex tests, including lying to standing, deep breathing, and the Valsalva maneuver, and 2-minute resting heart rate variability indices were obtained as measures of CAN. Effects of CAN risk factors on the risk of developing CAN were studied using multivariate logistic regression models. Linear mixed models were used to estimate the effect of risk factors on cardiovascular autonomic reflex tests and heart rate variability indices.
The investigators reported that “a progressive yet heterogeneous course of CAN occurred between the 6- and 13-year follow-ups.” Prevalent CAN was associated with higher glycated hemoglobin (HbA1c) levels, weight, body mass index (BMI), and triglycerides. There was no significant effect of risk factors when using cardiovascular autonomic reflex tests as continuous variables. However, higher levels of HbA1c and high-density lipoprotein cholesterol were associated with lower levels for the cardiovascular reflex tests, and higher HbA1c levels and BMI were associated with lower levels of heart rate variability indices, with effects decreasing over time for both.
According to the researchers, “the observed heterogeneous course of CAN may challenge the present clinical approach of categorically classifying [cardiovascular autonomic reflex tests] to diagnose CAN and the notion of CAN being irreversible.”
Andersen ST, Witte DR, Fleischer J, et al. Risk Factors for the presence and progression of cardiovascular autonomic neuropathy in type 2 diabetes: ADDITION-Denmark [published online October 10, 2018]. Diabetes Care. doi:10.2337/dc18-1411