In essential hypertension, a change in the renal resistive index is associated with a change in the ratio of 24-hour diastolic to systolic blood pressure.

An increase in the renal resistive index (RRI) in patients with essential hypertension (EH) predicts deterioration in renal function. In patients with EH, changes in hemodynamic parameters significantly affect the RRI. This study aimed to define changes in Ambulatory Blood Pressure Monitoring (ABPM) parameters that are significantly associated with a change in RRI in patients with EH. We evaluated ABPM and the RRI in 96 patients with EH without organ extrarenal changes at baseline and after two years of follow-up. The relationships between changes in ABPM parameters and the RRI over the period were evaluated. After two years of follow-up, the increase in RRI was consequential. Simultaneously, 24-h systolic blood pressure increased significantly and 24-h diastolic blood pressure decreased. In the whole group and in the group with calculated cystatin C clearance (eGFRcyst) >/=90 ml/min/1.73 m2, the change in RRI significantly negatively correlated with the change in the ratio of 24-h diastolic to systolic blood pressure (D/S ratio), but also with the change in 24-h pulse blood pressure. However, in patients with eGFRcyst>90 ml/min/1.73 m2, only the change in the 24-h D/S ratio significantly correlated with the change in RRI. Based on the backward stepwise regression analysis, the change in RRI was significantly dependent only on the change in 24-h D/S ratio and not on the change in 24-h pulse pressure. A change in the ratio of diastolic to systolic pressure better reflects a change in RRI than a change in pulse pressure.

Selective internal carotid artery cross-clamping increases the specificity of cerebral oximetry for indication of shunting during carotid endarterectomy.

BACKGROUND: An indication for selective shunting during carotid endarterectomy (CEA) is based on monitoring during a procedure. Cerebral oximetry (CO) using near-infrared spectroscopy (NIRS) may be a simple technique, but its relevance during CEA, especially with respect to cutoff values indicating shunt implantation, still needs to be elucidated. METHODS: One hundred twenty five patients underwent CEA under local anesthesia (LA) and were monitored clinically throughout the whole procedure. The patients were also monitored using bilateral NIRS probes during surgery. The NIRS values were recorded and evaluated before and after selective cross-clamping, firstly by the external carotid artery (ECA), followed by the internal carotid artery (ICA). The decrease in the ipsilateral CO values, with respect to the indication of shunting, was only analyzed after selective cross-clamping of the ICA. The decision to use an intraluminal shunt was solely based on the neurological status evaluation after ICA cross-clamping. RESULTS: One hundred five patients (85%) were stable throughout the CEA, while 20 patients (15%) clinically deteriorated during surgery. The mean drop in the CO after selective ICA clamping in clinically stable patients was 6%, while in patients with clinical deterioration, the NIRS decreased by 14.5% (p < 0.05). When the cutoff value for selective shunting was set as a 10% decrease of the ipsilateral CO after selective ICA clamping, the sensitivity of the technique was 100% and the specificity 83.0%. CONCLUSIONS: Our study showed that a 10% decrease in the ipsilateral brain tissue oximetry after selective cross-clamping the ICA provides a reliable cutoff value for selective shunting during CEA. Despite the availability of a variety of monitoring tools, the NIRS may be an easy, reliable option, especially in the scenario of acute CEA in general anesthesia.

The muscle-bone unit in adulthood: influence of sex, height, age and gynecological history on the bone mineral content and muscle cross-sectional area.

Bone and muscle development are both strongly influenced by sex hormones. The purpose of this study was to examine the changes in bone and muscle parameters (bone mineral content - BMC, muscle cross-sectional area - MA) in 130 men aged 31 -60 years, and in 180 pre-menopausal women aged 30-53 years with respect to age, body height and, with the women, their gynecological history (age-at-menarche, number of pregnancies, duration of lactation and use of oral contraception). The study was performed using peripheral quantitative computed tomography (pQCT) at a 65% site of the forearm length. Both BMC and MA were dependent on body height (p<0.0001), but not on age. The BMC/MA ratio was dependent neither on age nor on body height in both genders. MA as well as BMC were found significantly higher in males than in females (p<0.0001 for both variables). We observed a significantly higher BMC/MA ratio in females than in males (p<0.0001). We found no effect either of the analyzed variables of gynecological history on bone/muscle characteristics. The findings highlight the necessity of involving height-adjusted parameters and BMC/MA ratio into bone analysis in adults.

[Primary prevention of ischemic heart disease in middle-aged men living in Prague: results of twenty-year research]. / Primární prevence ischemické choroby srdecní u muzu stredního veku v Praze: výsledky dvacetiletého sledování.

INTRODUCTION: Ischemic Heart Disease (IHD) represents the most frequent cause of mortality and morbidity in the Czech Republic. The aim of this study is to analyze long-term mortality of cardiovascular disease (CVD), identify its predictors and verify the validity of Framingham risk function for Czech patients. DESIGN AND METHODS: The twenty-year study (STULONG) of primary prevention of risk factors of atherosclerosis in 1419 men aged 38 to 53 years living in Prague was started in 1975. RESULTS: CVD mortality analysis showed a higher risk of death for heavy smokers vs. non-smokers or light smokers (p < 0.0001), hypertensive patients vs. patients with normal blood pressure (p < 0.0001), men with hypercholesterolemia vs. men with normal cholesterol level (p = 0.0432), and a lower risk for university graduates vs. men with elementary education (p = 0.0006). Between 1980 and 1984, age-specific CVD mortality rates of men from STULONG study were higher (p = 0.0132) than national CVD mortality rates; between 1985 and 1994, they were insignificantly lower. Framingham risk function underestimated absolute ten-year risk of IHD in all risk quintiles (p < 0.0001) with discrimination of 63%. CONCLUSION: CVD mortality observed within STULONG study was significantly affected by known risk factors (hypertension, smoking, hypercholesterolemia, lower education); Framingham risk function underestimated absolute ten-year risk of IHD.

Primary prevention of coronary artery disease among middle aged men in Prague: twenty-year follow-up results.

BACKGROUND: Coronary artery disease (CAD) represents the most common cause of morbidity and mortality in the Czech Republic. The aim of this study is to analyze long-term cardiovascular diseases (CVD) mortality, identify predictors of outcome and to validate the Framingham risk function in men from the Czech Republic. DESIGN AND METHODS: A 20-year primary prevention study of atherosclerosis risk factors in 1417 men from Prague aged 38-53 years was launched in 1975 (STULONG). RESULTS: When analyzing CVD mortality, heavy smokers had hazard higher than non-smokers and light smokers (p < 0.0001); hypertensives higher than normotensives (p < 0.0001); men with hypercholesterolemia higher than those with normal cholesterol (p = 0.0432), and university-educated men lower than elementary-educated men (p = 0.0006). In 1980-1984, the age specific mortality from CVD in men from STULONG was higher (p = 0.0132) than in the Czech Republic, in 1985-1994 insignificantly lower. The Framingham risk function underestimated the absolute 10-year risk of CAD across the quintile of the risk (p < 0.0001), with 63% discrimination. CONCLUSION: In STULONG, the mortality from CVD was significantly associated with known risk factors (hypertension, smoking, hypercholesterolemia, education); the Framingham risk function underestimated the absolute 10-year risk of CAD.

Comparison of survival between two groups using software SAS, S-PLUS and STATISTICA.

In survival analysis, comparison of survival times between two groups of patients is often the goal. For this purpose, Mantel-Haenszel (or log-rank) test is usually used. This paper introduces a concrete example to illustrate similarities as well as differences among the statistical programs SAS, S-PLUS and STATISTICA, when performing Mantel-Haenszel test.