Cardiovascular autonomic neuropathy contributes to left ventricular diastolic dysfunction in subjects with Type 2 diabetes and impaired glucose tolerance undergoing coronary angiography.

AIMS: Left ventricular diastolic dysfunction is considered a precursor of diabetic cardiomyopathy, while diabetic cardiovascular autonomic neuropathy is associated with an increased risk of mortality. This study aimed to evaluate the association between left ventricular diastolic dysfunction and cardiovascular autonomic neuropathy, both diagnosed according to the current guidelines. METHODS: We evaluated 145 patients referred for an elective coronary angiography, 52 of whom had Type 2 diabetes and 48 had impaired glucose tolerance, while 45 subjects had normal glucose tolerance. Cardiovascular autonomic neuropathy was diagnosed using autonomic function tests, while left ventricular diastolic dysfunction was verified by tissue Doppler imaging echocardiography. RESULTS: Cardiovascular autonomic neuropathy was diagnosed in 15 (28.8%) patients with Type 2 diabetes and in six (12.5%) individuals with impaired glucose tolerance. The rates of left ventricular diastolic dysfunction were 81 and 33% in patients with and without cardiovascular autonomic neuropathy, respectively (P < 0.001). In the cardiovascular autonomic neuropathy group (n = 21), early diastolic relaxation velocity (Em) was significantly reduced (5.4 ± 0.9 vs. 7.3 ± 2.1 cm/s; P < 0.001) and the E/Em ratio was significantly higher (13.6 ± 4.6 vs. 10.3 ± 3.4 cm/s, P < 0.001) as compared with the group without cardiovascular autonomic neuropathy (n = 79). These findings remained significant after adjustment for age, sex, coronary artery disease, hypertension and HbA(1c) . A severe form of left ventricular diastolic dysfunction was observed in 33 and 15% of patients with and without cardiovascular autonomic neuropathy, respectively (P = 0.001). CONCLUSION: Cardiovascular autonomic neuropathy is associated with a higher prevalence and a more severe form of left ventricular diastolic dysfunction in patients with diabetes or impaired glucose tolerance undergoing coronary angiography. Because both cardiovascular autonomic neuropathy and left ventricular diastolic dysfunction are associated with increased cardiovascular morbidity and mortality, screening for patients with left ventricular diastolic dysfunction and cardiovascular autonomic neuropathy with diabetes or impaired glucose tolerance may identify those at high risk.

Newly detected glucose disturbance is associated with a high prevalence of diastolic dysfunction: double risk for the development of heart failure?

Diastolic dysfunction is associated with a high rate of morbidity and mortality and has a high prevalence in patients with diabetes. Aim of the study was to investigate the prevalence of diastolic dysfunction in patients with newly detected glucose metabolism disorder (GMD) submitted for coronary angiography. Oral glucose tolerance test, echocardiography, and tissue Doppler imaging were performed in patients referred to coronary angiography. Prevalence of diastolic dysfunction was 97, 88, and 74% in the known diabetes, newly detected diabetes, and new diagnosed impaired glucose tolerance group, respectively. This is higher than previously reported. Severity of diastolic dysfunction was associated with higher 2-h plasma glucose levels and with new diagnosed diabetes. Screening patients with newly detected GMD for diastolic dysfunction may identify patients with double risk for cardiovascular morbidity and mortality and this group might be a target population to avoid development heart failure.

Increased TNF-alpha and decreased TGF-beta expression in peripheral blood leukocytes after acute myocardial infarction.

Inflammation contributes to the development of atherosclerosis and cardiovascular events. Counteracting pro- and anti-inflammatory responses of serum cytokines have been reported, but the relevance of TNF-alpha, TGF-beta and IL-6 gene expression in peripheral blood leukocytes and their contribution to systemic inflammation in atherosclerosis, especially after acute myocardial infarction (AMI), has not been investigated yet. Using quantitative RT-PCR, we determined temporal cytokine mRNA expression alterations in blood cells from patients with AMI (n = 51). Serum cytokine concentrations were analyzed in parallel using the ELISA technique. TNF-alpha mRNA expression rates and serum concentrations were significantly elevated in AMI patients compared to controls (n = 77), while mRNA expression and serum content of TGF-beta were decreased. Interestingly, we found no statistically significant correlation between transcript and protein levels, indicating that gene expression in leukocytes may be an independent sign for systemic inflammation. While IL-6 was significantly increased in serum from AMI patients with positive correlation to left ventricular dysfunction and negative correlation to ejection fraction, IL-6 mRNA levels did not differ between patients and controls. Gene expression alterations indicate a sophisticated regulation of counteracting TNF-alpha and TGF-beta cytokine expression in peripheral blood leukocytes after AMI with bias towards a pro-inflammatory situation.

High prevalence of undiagnosed impaired glucose regulation and diabetes mellitus in patients scheduled for an elective coronary angiography.

BACKGROUND: Impaired glucose regulation (IGR) and diabetes mellitus (DM) are amongst the main risk factors for developing coronary heart disease (CHD). The aim of this study was to investigate previously unknown glucose metabolism disorder in patients scheduled for an elective coronary angiography. METHODS: A total of 141 patients scheduled for coronary angiography without signs of acute myocardial ischemia or previous history of a glucose metabolism disorder were prospectively included in the study. An oral glucose tolerance test (OGTT) was performed in each patient. RESULTS: IGR was diagnosed in 40.4% (95% confidence interval 32.3-49.0) and undetected DM in 22.7% (16.1-30.5) of patients undergoing an elective coronary angiography. Depending on the severity of CHD, the percentage of IGR and DM increased up to 45.3% (34.6-56.5) and 26.7% (17.8-37.4) in the subgroup with the need of percutaneous angioplasty, while the corresponding proportions in the group without CHD were 30.3% (15.6-48.7) and 12.1% (3.4-28.2). The percentage of undiagnosed DM increased with the number of epicardial vessels involved. Using the recommended fasting plasma glucose value of > or = 126 mg/dl for the diagnosis of DM, we would have missed 71.9% of the patients with undiagnosed DM. If all patients with a fasting plasma glucose of > or = 90 mg/dl had been subjected to OGTT, 93.8% of DM would have been identified. CONCLUSIONS: Prevalences of DM and IGR are higher than expected in patients with CHD. An OGTT should be considered for all patients with a fasting plasma glucose > or = 90 mg/dl undergoing a coronary angiography.