Ambulatory Blood Pressure Monitoring as a Useful Tool in the Cardiological Assessment of Pancreas Transplant Recipients with Type 1 Diabetes.

Having the appropriate tools to identify pancreas recipients most susceptible to coronary artery disease (CAD) is crucial for pretransplant cardiological assessment. The aim of this study is to evaluate the association between blood pressure (BP) indices provided by ambulatory blood pressure monitoring (ABPM) and the prevalence of CAD in pancreas transplant candidates with type 1 diabetes (T1D). This prospective cross-sectional study included adult T1D patients referred for pretransplant cardiological assessment in our center. The study population included 86 participants with a median age of 40 (35-46) years. In multivariate logistic regression analyses, after adjusting for potential confounding factors, higher 24 h BP (systolic BP/diastolic BP/pulse pressure) (OR = 1.063, 95% CI 1.023-1.105, p = 0.002/OR = 1.075, 95% CI 1.003-1.153, p = 0.042/OR = 1.091, 95 CI 1.037-1.147, p = 0.001, respectively) and higher daytime BP (systolic BP/diastolic BP/pulse pressure) (OR = 1.069, 95% CI 1.027-1.113, p = 0.001/OR = 1.077, 95% CI 1.002-1.157, p = 0.043/OR = 1.11, 95% CI 1.051-1.172, p = 0.0002, respectively) were independently and significantly associated with the prevalence of CAD. Daytime pulse pressure was the strongest indicator of the prevalence of CAD among all analyzed ABPM parameters. ABPM can be used as a valuable tool to identify pancreas recipients who are most susceptible to CAD. We suggest the inclusion of ABPM in pretransplant cardiac screening in type 1 diabetes patients eligible for pancreas transplantation.

Comparison of safety of radial and femoral approaches for coronary catheterization in interventional cardiology.

BACKGROUND: The femoral approach has been the preferably used access in interventional cardiology as well for coronary diagnostics as for percutaneous coronary intervention, being perceived as easy and facilitating quick access with relatively low risk. Due to the results of the latest studies, however, the radial approach has become increasingly popular. The aim of this study was a safety analysis of cardiological interventional procedures (i.e., coronarography and PCI) according to the vessel approach. MATERIAL/METHODS: The 204 coronary interventions done in our Department of Interventional Cardiology were retrospectively analyzed. All the procedures were classified according to femoral or radial access. The incidence of local complications (e.g., major bleedings and hematomas) was assessed as well as the volume of contrast agent administered during the procedure and the radiation dose. RESULTS: It has been shown that radial approach, which is obviously more comfortable for patients, reduces the risk of local complications (0 vs. 2.97% and 0 vs. 3.96%) and does not lead to increased radiation exposure (p=0.88). However, there could be a larger volume of contrast agent administered (p=0.029), which in some cases could increase the risk of contrast-induced nephropathy. CONCLUSIONS: The radial approach should be recommended as a first choice because it is safer than the classical femoral approach, but one must be cautious in choosing radial approach patients with renal insufficiency.

[Selected, biochemical markers of hypoxia]. / Wybrane, biochemiczne markery hipoksji.

Although tissues may exist regardless of reduced oxygen pressure, this requires glycolytic ATP generation, which is very expensive from the energetic viewpoint. Hypoxia is defined as the condition in which oxygen pressure is reduced at the level of bodily tissues. There are many clinical situations during which decreased tissue oxygenation may occur. It may be transient or chronic, as well as systemic or local. An emergent need exists for monitoring and diagnosis with respect to numerous possible clinical circumstances leading to hypoxia and its life-threatening consequences. The assessment of global oxygen homeo-stasis relies on blood gas analysis and lactate concentration, but such an approach does not fully reflect the local oxygenation of tissues. Oxygen needle microelectrode measurements reveal great differences in tissue pO2 levels. Local pO2 levels depend on many factors, among which the most important are: the distance to the nearest capillary, the extracellular and intracellular fluid diffusion rates and intracellular measurements of the number and activity levels of mitochondria. Thus, nowadays, it is impossible to establish an accurate normal value ranges for local tissue pO2. Oxygen deficiency is an important gene regulator. A sequence-specific DNA-binding factor, the hypoxia induced factor (HIF), is the fundamental hypoxia response protein. 70 genes identified so far have been found to be HIF-dependent. They are responsible for increased oxygen delivery, i.e. by boosting angiogensis due to vascular endothelial growth factor (VEGF) release and the enhancement of red blood cell production by erythropoietin (EPO). VEGF-induced angiogenesis is one of several key hypoxia adaptations. An enhanced vascular bed in response to hypoxia affects almost every bodily tissue and organ. This was observed particularly in skeletal muscles as well as in the brain. The expression of a few hypoxia markers does not require HIF activation. An especially interesting member of this group is osteopontin (OPN), whose synthesis increases during hypoxia. OPN was originally linked to bone remodeling, but currently it seems to posses an important role in immunity, inflammation and tumor pathogenesis. Quantification of hypoxia is clinically essential both for therapy and prognosis. Taking account of the fact that the concept of oxygen pressure at the tissue level is not quantitative (norms do not exist, results are incomparable), biochemical markers are preferable. Particularly significant in this context are hypoxia-induced proteins such as HIF, EPO, VEGF or potentially OPN.

[Role of hemoglobin affinity to oxygen in adaptation to hypoxemia]. / Znaczenie powinowactwa hemoglobiny do tlenu w adaptacji do hipoksemii.

UNLABELLED: One of the basic mechanisms of adapting to hypoxemia is a decrease in the affinity of hemoglobin for oxygen. This process occurs mainly due to the increased synthesis of 2,3-diphosphoglycerate (2,3-DPG) in the erythrocytes, as well as through the Bohr effect. Hemoglobin with decreased affinity for oxygen increases the oxygenation of tissues, because it gives up oxygen more easily during microcirculation. In foetal circulation, however, at a partial oxygen pressure (pO2) of 25 mmHg in the umbilical vein, the oxygen carrier is type F hemoglobin which has a high oxygen affinity. The commonly accepted role for hemoglobin F is limited to facilitating diffusion through the placenta. Is fetal life the only moment when haemoglobin F is useful? THE AIM OF STUDY was to create a mathematical model, which would answer the question at what conditions an increase, rather than a decrease, in haemoglobin oxygen affinity is of benefit to the body. MATERIAL AND METHODS: Using the kinetics of dissociation of oxygen from hemoglobin described by the Hill equation as the basis for further discussion, we created a mathematical model describing the pO2 value in the microcirculatory system and its dependence on arterial blood pO2. The calculations were performed for hemoglobin with low oxygen affinity (adult type) and high-affinity hemoglobin (fetal type). The modelling took into account both physiological and pathological ranges of acid-base equilibrium and tissue oxygen extraction parameters. RESULTS: It was shown that for the physiological range of acid-base equilibrium and the resting level of tissue oxygen extraction parameters, with an arterial blood pO2 of 26.8 mmHg, the higher-affinity hemoglobin becomes the more effective oxygen carrier. It was also demonstrated that the arterial blood pO2, below which the high-affinity hemoglobin becomes the more effective carrier, is dependent on blood pH and the difference between the arterial and venous oxygen saturation levels. Simulations performed for the pathological states showed that acidosis and increased tissue oxygen demand lead to a broadened arterial blood pO2 range, in which the high-affinity hemoglobin is more efficient. CONCLUSIONS: Contrary to the widely held view that the only response to hypoxemia is a decrease in haemoglobin oxygen affinity, it was shown that under extreme hypoxemic conditions, an increased haemoglobin oxygen affinity improves the oxygenation of tissues. It was also shown that the dominance of hemoglobin with a high oxygen affinity rapidly exceeds hemoglobin with low oxygen affinity in the case of acidosis with its accompanying high tissue oxygen extraction. In cases of extreme disruptions of the acid-base equilibrium, the dominance of high-oxygen-affinity hemoglobin spans over the entire possible range of pO2 in arterial blood.