[Heart pathology of extracardiac origin. XI. Cardiac repercussions of diabetes mellitus]

Miocardiopatía diabética

The world-wide estimated prevalence of diabetes mellitus for 2025 is of about 300 million, resulting from a higher prevalence of obesity and sedentary lifestyles in the developed world. The group of cardiovascular diseases is responsible for 80% of deaths among diabetic patients. Several authors have suggested that patients with diabetes mellitus have a predisposition to develop a form of cardiomyopathy, known as <<diabetic cardiomyopathy>>, which is not related to ischemic heart disease or hypertension, and may progress to cardiac failure. Such condition is known to be associated with a poor prognosis in patients with diabetes mellitus. The prevalence appears to be high. Thus, tissue Doppler techniques added to conventional echocardiography assessment have estimated it to be as high as 75%. However, the use of echocardiography as a screening tool in the asymptomatic diabetic population is problematic. Biomarkers of cardiac dysfunction have been proposed for diagnosis. In this article, we have assessed the role of biomarkers in the diagnosis of this condition and proposed a diagnostic algorithm that may be useful for the assessment of asymptomatic patients with diabetes.

Cellular aspects of intestinal lipoprotein assembly in Psammomys obesus: a model of insulin resistance and type 2 diabetes

Although postprandial hypertriglyceridemia is a major contributing factor in the development of atherosclerosis, little information is available on the effect of insulin resistance and diabetes on intestinal fat transport. The aim of the present study was to examine intracellular events that govern lipid transport and apolipoprotein (apo) B-48-containing lipoprotein assembly in the small intestine of Psammomys obesus, a model of nutritionally induced insulin resistance and type 2 diabetes. Animals with normoglycemia/hyperinsulinemia and hyperglycemia/hyperinsulinemia exhibited high levels of triglycerides (TGs) in the plasma and intestine and postprandial plasma chylomicrons and apo B-48 compared with normoglycemic/normoinsulinemic animals. In vitro studies, using cultured jejunal explants incubated with either [14C]oleic acid or [35S]methionine, revealed their higher efficiency in de novo TG synthesis, apo B-48 biogenesis, and TG-rich lipoprotein assembly. Accordingly, enhanced monoacylglycerol and diacylglycerol acyltransferase activity was also discernible and concomitant with an increased content of L-fatty acid binding protein and in vivo chylomicron production rates. However, both the I-fatty acid binding protein amount and the apo B-48 proteasomal degradative pathway were decreased. Overall, our findings show that the development of an insulin-resistant/diabetic state in Psammomys obesus triggers the whole intra-enterocyte machinery, leading to lipoprotein assembly and favoring the intestinal oversecretion of apo B-48-lipoproteins, which may contribute to characteristic hypertriglyceridemia.

[Prognosis of diabetic patients with ischemic cardiopathy]

The prevalence of diabetes in Spain is about 6% and increases with age and obesity. Diabetes is present in approximately 25% of patients with coronary heart disease (CHD). Pre-diabetic and diabetic patients have a higher incidence of CHD and poorer prognosis, with high short- and long-term mortality. The protective effect of pre-menopause status is suppressed by diabetes. Diabetes has a synergic effect with other cardiovascular risk factors. Primary prevention in diabetic patients should be approached as in non-diabetic post-infarction patients. In diabetes, a healthy life-style and strict control of blood sugar and the other cardiovascular risk factors, particularly hypertension, is mandatory.