The Degree of Autonomic Modulation Is Associated With the Severity of Microvascular Complications in Patients With Type 1 Diabetes

Abstract

Neurological and Microvascular FunctionHeart rate variability (HRV) is a widely accepted noninvasive measure of balance/imbalance in the autonomic nervous system, HRV is defined as the variation in heart rate from beat to beat (RR interval) caused by changes in breathing, blood pressure, sympathoadrenal hormones, as well as mental, physical, and certain pathological conditions. In the general population, low HRV has been associated with compromised health and independently predicts all-cause mortality. [1][2][3] Moreover, in diabetes patients, the presence of autonomic dysfunction has been suggested as a prognostic marker of complications 4,5 and the presence of autonomic dysfunction may occur before other late complications. 5Detailed HRV analysis, including both cardiovascular reflex tests and frequency domain analysis, are an important tool to estimate cardiac autonomic nervous activity. 6,7 Several studies indicate that spectral analysis in particular, describing frequency-specific fluctuations in heart rate, may be a more sensitive tool to detect autonomic imbalance compared to active tests. 8,9 However, it is unknown if the cardiovascular reflex tests and frequency domain analysis decrease according to the severity of microvascular complications or are limited to diagnose cardiovascular autonomic neuropathy (CAN).The objective of this study was therefore to elucidate the association between the degree of autonomic modulation, The objective of this study was to elucidate whether the degree of autonomic modulation is associated with the degree of microvascular complications in patients with type 1 diabetes. Methods: A total of 290 type 1 individuals with diabetes were randomly recruited during normal visits to outpatient clinics at 4 Danish hospitals. The degree of autonomic modulations was quantified by measuring heart rate variability (HRV) during passive spectral analysis and active tests (valsalva ratio [VT], response to standing [RT], and deep breathing [E:I]). To describe possible associations between severity of microvascular complications and measures of autonomic modulation, multivariate analysis was performed. Results: After adjusting for diabetes duration, sex, age, pulse pressure, heart rate, and smoking, autonomic dysfunction remained significantly correlated with severity of retinopathy, nephropathy, and peripheral neuropathy in individuals with type 1 diabetes patients. Conclusions: Autonomic dysfunction is present in early stages of retinopathy, nephropathy, and peripheral neuropathy in patients with type 1 diabetes.

Is there a connection between postprandial hyperglycemia and IGT related sensory nerve dysfunction?

“…Cardiovascular autonomic neuropathy has been documented to be associated with the presence of peripheral polyneuropathy [11,29]. Although at borderline siginificance cardiovascular autonomic neuropathy was independently related to sensory nerve dysfunction in our pooled population as well.…”

Risk Factors for the Presence and Progression of Cardiovascular Autonomic Neuropathy in Type 2 Diabetes: ADDITION-Denmark

“…Controlling the breathing rate enables an easier separation of the LF and HF. At the same time, however, controlled breathing may affect HRV indices by shifting the sympathovagal balance toward vagal predominance (37). We found rather homogeneous levels of risk factors, which varied little, and this may have hindered the identification of further significant risk factor associations (31,32).…”

Palpebral Fissure Response to Phenylephrine Indicates Autonomic Dysfunction in Patients With Type 1 Diabetes and Polyneuropathy

“…Not surprisingly, several studies have found associations between severity of DR and autonomic dysfunction in type 1 13 , 14 and type 2 diabetes, 15 , 16 because they both represent long-term diabetic microvascular complications. In fact, Huang et al 33 have suggested that DR is the most significant predictive risk factor of CAN in patients with type 2 diabetes, and retinopathy is an independent risk marker for cardiovascular diseases, such as cardiovascular deaths, 34 stroke, major cardiovascular events, and peripheral artery disease.…”