Empfehlungen der Projektgruppe Pr?vention der DGK zur risikoadjustierten Pr?vention von Herz- und Kreislauferkrankungen

Primary prevention of coronary artery disease (CAD) is becoming increasingly important because of the treatment costs of CAD. The assessment of overall cardiovascular risk is of importance to evaluate the effectiveness of medical therapy. Risk stratification in Germany is usually performed using the PROCAM algorithm or the ESC score. If the 10-year risk of myocardial infarction (PROCAM) or cardiovascular death (ESC SCORE) exceeds 20 or 5%, respectively, intensive risk intervention including medical therapy is cost-effective and the number needed to treat (NNT) is usually?<?200. An NNT of?<?200 can also be achieved by treating a single pronounced risk factor. The CARRISMA system uses lifestyle factors in addition to conventional factors to improve risk stratification and also supports lifestyle modification. During the last two decades average life expectancy has increased by 6?years and possibilities for prevention have improved. Risk stratification for prevention should therefore be offered up to the age of 70. Risk scores support evidence-based and cost-effective prevention.     

Notwendigkeit von körperlicher Aktivität als Baustein der Prävention

Endothelial dysfunction has been identified as a major predictor of future cardiovascular events and precedes the development of coronary artery disease (CAD). In patients with CAD and preserved left ventricular function regular physical exercise training corrects endothelial dysfunction, thus augmenting myocardial perfusion and reducing mortality in these patients. Exercise intolerance in chronic heart failure is not only the consequence of central hemodynamic alterations but also the result of peripheral maladaptations, in particular of the endothelium and the skeletal muscle. Regular, aerobic exercise training has been shown to partially correct these intrinsic alterations and to improve exercise capacity in these patients. In addition, regular aerobic exercise training might have the potential to reduce mortality in these patients as well, but further studies are necessary to address this issue.     

Electrophysiological aspects of human sphincter function

In order to investigate the electrophysiology of the human internal anal sphincter and two current concepts of sphincter function, simultaneous manometric and electrical recordings were made from circular smooth muscle of the internal anal sphincter in the resting state and during reflexly induced sphincter relaxation. Three groups were studied: seven normal subjects, 25 patients with functional bowel disease, and seven patients with external sphincter paralysis due to spinal cord lesions. In the resting state slow waves of alternating potential (basic electrical rhythm or BER) were recorded in all subjects. Two types of waves were present, a constant sinusoidal pattern or a spindleshaped pattern. Either pattern was consistent for a given individual. Frequency of BER in the internal sphincter was higher than that recorded in any other gastrointestinal muscle. Our findings indicate that the BER recorded from the internal anal sphincter originates in this muscle. This activity may represent a specialized feature of sphincteric muscle since BER cannot be recorded from isolated nonsphincteric circular muscle.     

Hypoxia modulates cholinergic but not opioid activation of G proteins in rat hippocampus

Intermittent hypoxia, such as that associated with obstructive sleep apnea, can cause neuronal death and neurobehavioral dysfunction. The cellular and molecular mechanisms through which hypoxia alter hippocampal function are incompletely understood. This study used in vitro [(35)S]guanylyl-5'-O-(gamma-thio)-triphosphate ([(35)S]GTP gamma S) autoradiography to test the hypothesis that carbachol and DAMGO activate hippocampal G proteins. In addition, this study tested the hypothesis that in vivo exposure to different oxygen (O(2)) concentrations causes a differential activation of G proteins in the CA1, CA3, and dentate gyrus (DG) regions of the hippocampus. G protein activation was quantified as nCi/g tissue in CA1, CA3, and DG from rats housed for 14 days under one of three different oxygen conditions: normoxic (21% O(2)) room air, or hypoxia (10% O(2)) that was intermittent or sustained. Across all regions of the hippocampus, activation of G proteins by the cholinergic agonist carbachol and the mu opioid agonist [D-Ala(2), N-Met-Phe(4), Gly(5)] enkephalin (DAMGO) was ordered by the degree of hypoxia such that sustained hypoxia > intermittent hypoxia > room air. Carbachol increased G protein activation during sustained hypoxia (38%), intermittent hypoxia (29%), and room air (27%). DAMGO also activated G proteins during sustained hypoxia (52%), intermittent hypoxia (48%), and room air (43%). Region-specific comparisons of G protein activation revealed that the DG showed significantly less activation by carbachol following intermittent hypoxia and sustained hypoxia than the CA1. Considered together, the results suggest the potential for hypoxia to alter hippocampal function by blunting the cholinergic activation of G proteins within the DG.