Links between Metabolic Syndrome and Cardiovascular Autonomic Dysfunction

Abstract

Background. Type 2 diabetes (T2D) might occur within metabolic syndrome (MbS). One of the complications of T2D is an impaired (imp) cardiovascular autonomic function (CAF). Aims. In subjects with T2D and age ≤ 55 years, the prevalence of impCAF and its relationship with BMI, waist, HbA1c values, MbS, hypertension, and family history of T2D and/or hypertension were analysed. Methods. 180 subjects consecutively undergoing a day hospital for T2D were studied. The IDF criteria were used to diagnose MbS. To detect impCAF, 5 tests for the evaluation of CAF were performed with Cardionomic (Meteda, Italy). Univariate and multivariate analyses were performed. Results. The prevalence of impCAF and MbS were 33.9% and 67.8%, respectively. Among diabetics with impCAF, 86.9% had MbS. ImpCAF was significantly associated with MbS, overweight, and HbA1c > 7%. Both logistic (P = 0.0009) and Poisson (P = 0.0113) models showed a positive association between impCAF and MbS. The degree of ImpCAF showed a positive linear correlation with BMI and HbA1c values. Conclusions. The study demonstrates that glycaemic control and overweight influence CAF and that T2D + MbS is more strongly associated with impCAF than isolated T2D. We suggest that MbS not only increases the cardiovascular risk of relatively young subjects with T2D but is also associated with impCAF.

Links between Autonomic Dysfunction and Metabolic Syndrome

“…Overweight also has a negative effect on glycaemic control. In this line of evidence in our study we demonstrate a significant association between high HbA1c values (HbA1c >7.0%) and the occurrence of at least one abnormal test [8]. HbA1c is an established parameter to assess mean glycemia over the preceding 3 months.…”

“…Both PH and decreased heart rate variability are more frequent and severe 5 years after the diagnosis of Diabetes [36]. Unexpectedly, we found no association between CAF score and the duration of Diabetes, however, the subjects of our cohort [8], probably had a better metabolic memory than that of subjects from previous studies, not only because they were younger than those considered in previous studies, but also because they experienced a program of education to healthy life-style together with insulin and /or oral antidiabetic agents of last generation since the onset of Diabetes.…”

“…In a recent paper from our group we screened for cardiovascular autonomic neuropathy 180 subjects with type 2 diabetes with mean age of 48 years and we also analyzed whether any relationship existed between the nutritional habits of our cohort and the occurrence of any deficit of the autonomic function [8]. Interestingly, subjects with impaired CAF more often had MetS as compared with subjects with normal CAF but also eat a higher amount of saturated fat (higher amount of cheese and fat meet) as compared with diabetics who did not show any sign of abnormal CAF and MetS Unexpectedly, subjects with impaired CAF and MetS chose a western-style diet even if they were living in a mediterranean area [8]. Some data already exist about subjects with MetS who showed an improvement in their chronic low-grade inflammatory state (reduction in serum concentrations of C-reactive protein, interleukin-6, insulin-resistance, and improved endothelial function score) after experiencing a mediterranean-style diet (high content of whole grains, fruits, vegetables, nuts, and olive oil).…”

“…However, in subjects with DM, cardiovascular risk becomes higher when clinical features of the MetS are present along with DM [7,8]. When an impaired balance between the sympathetic and parasympathetic regulation of the cardiovascular function arises, a worsening of the prognosis of Diabetes already occurs.…”

Analysis of the Synergistic Effects of Fasting Plasma Glucose and Hypertension on Cardiovascular Autonomic Neuropathy

“…Recent studies have indicated that CAN is associated with many other majority segments of the general population, such as the elderly and patients with HTN and metabolic disorders [5,7,8]. Studies have provided evidence that CAN is common in persons with an impaired glucose tolerance.…”