Cardiovasc Diabetol
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Cardiovasc Diabetol · Jan 2010
Sleep apnea predicts distinct alterations in glucose homeostasis and biomarkers in obese adults with normal and impaired glucose metabolism.
Notwithstanding previous studies supporting independent associations between obstructive sleep apnea (OSA) and prevalence of diabetes, the underlying pathogenesis of impaired glucose regulation in OSA remains unclear. We explored mechanisms linking OSA with prediabetes/diabetes and associated biomarker profiles. We hypothesized that OSA is associated with distinct alterations in glucose homeostasis and biomarker profiles in subjects with normal (NGM) and impaired glucose metabolism (IGM). ⋯ OSA is independently associated with altered glucose homeostasis and increased basal beta-cell function in severely obese adults with NGM. The findings suggest that moderate to severe OSA imposes an excessive functional demand on pancreatic beta-cells, which may lead to their exhaustion and impaired secretory capacity over time. The two distinct biomarker profiles linking sleep apnea with NGM and IGM via TNF-α and IL-6 have been discerned in our study to suggest that sleep apnea and particularly nocturnal oxyhemoglobin desaturations are associated with chronic metabolic fluxes and specific cytokine stressors that reflect links between sleep apnea and glucose metabolism. The study may help illuminate potential mechanisms for glucose dysregulation in OSA, and resolve some controversy over the associations of OSA with TNF-α and IL-6 in previous studies.
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Cardiovasc Diabetol · Jan 2010
Determinants and prognostic implications of cardiac troponin T measured by a sensitive assay in type 2 diabetes mellitus.
The cardiac troponins are biomarkers used for diagnosis of myocardial injury. They are also powerful prognostic markers in many diseases and settings. Recently introduced high-sensitivity assays indicate that chronic cardiac troponin elevations are common in response to cardiovascular (CV) morbidity. Type 2 diabetes mellitus (T2DM) confers a high risk of CV disease, but little is known about chronic cardiac troponin elevations in diabetic subjects. Accordingly, we aimed to understand the prevalence, determinants, and prognostic implications of cardiac troponin T (cTnT) elevations measured with a high-sensitivity assay in patients with T2DM. ⋯ Elevations of cTnT above the 99th percentile measured by a highly sensitive assay were encountered frequently in a population of T2DM patients. cTnT levels appeared to be stable over time and associated with conventional CV risk factors. Although a clear trend was present, no statistically robust associations with adverse outcomes could be found.
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Cardiovasc Diabetol · Jan 2010
"If it ain't broke, don't fix it": a commentary on the positive-negative results of the ACCORD Lipid study.
Even using intensive statin monotherapy, many patients fail to achieve all the desired lipid goals and remain at high residual risk of cardiovascular events. In view of the still unproven decisively intensive "statin as monotherapy" strategy and "residual risk" concept, it is logical to ask whether other strategies, particularly fibrate/statin combination therapy, could be more beneficial and safer. A clear benefit of fibrate monotherapy did emerge previously among patients with atherogenic dyslipidemia (particularly high triglycerides and low high density lipoprotein cholesterol [HDL-C]) typically present in the metabolic syndrome and type 2 diabetes. ⋯ Therefore, an important finding of ACCORD Lipid study was the observation that fibrates may lead to cardiovascular risk reduction in patients with atherogenic dyslipidemia not only as monotherapy but in combination with statins as well. In conclusion, in patients with atherogenic dyslipidemia (high triglycerides and low HDL-C, fibrates -- either as monotherapy or combined with statins - were associated with reduced risk of cardiovascular events. In patients without dyslipidemia this favorable effect - as expected - was absent.
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Cardiovasc Diabetol · Jan 2010
Advanced glycation end products induce chemokine/cytokine production via activation of p38 pathway and inhibit proliferation and migration of bone marrow mesenchymal stem cells.
Advanced glycation products (AGEs), as endogenous inflammatory mediator, compromise the physiological function of mesenchymal stem cells (MSCs). MSCs have a potential role in cell replacement therapy in acute myocardial infarction and ischemic cardiomyopathy. However, mechanisms of AGEs on MSCs are still not unveiled. ⋯ The study indicates that AGE-BSA induces production of chemokines/cytokines in a dose- and time-dependent manner via activation of ROS-p38 mediated pathway. These chemokines/cytokines exert an inhibitory effect on MSC growth and migration, suggesting an amplified dysfunction of MSCs by AGEs.
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Cardiovasc Diabetol · Jan 2010
Glucagon-like peptide-1 and the exenatide analogue AC3174 improve cardiac function, cardiac remodeling, and survival in rats with chronic heart failure.
Accumulating evidence suggests glucagon-like peptide-1 (GLP-1) exerts cardioprotective effects in animal models of myocardial infarction (MI). We hypothesized that chronic treatment with GLP-1 or the exenatide analog AC3174 would improve cardiac function, cardiac remodeling, insulin sensitivity, and exercise capacity (EC) in rats with MI-induced chronic heart failure (CHF) caused by coronary artery ligation. ⋯ Chronic treatment with either GLP-1 or AC3174 showed promising cardioprotective effects in a rat model of CHF. Hence, GLP-1 receptor agonists may represent a novel approach for the treatment of patients with CHF or cardiovascular disease associated with type 2 diabetes.