1,720,957 research outputs found
Plasma glucose levels and left ventricular diastolic function in nondiabetic hypertensive patients
No full textBACKGROUND:
Changes in left ventricular (LV) diastolic filling anticipate diastolic heart failure and are frequently detected in patients with hypertension or diabetes. We tested the hypothesis that increased fasting and postload glucose levels are associated with diastolic dysfunction as assessed by tissue Doppler imaging (TDI) in hypertensive patients.
METHODS:
In 104 untreated, nondiabetic, hypertensive patients free of cardiovascular complications, we measured glucose and insulin at fast and after an oral glucose load, calculated the Homeostatic Model Assessment (HOMA) index, and performed electrocardiogram (ECG), conventional echocardiography, and TDI.
RESULTS:
Thirty-one patients who had impaired fasting glucose/impaired glucose tolerance had more frequent LV strain at ECG and worse TDI markers of diastolic function than patients with normal plasma glucose but no differences in variables LV mass, LV geometry, systolic function, and early-/late-wave transmitral diastolic velocity. TDI detected diastolic dysfunction in 46 patients who were older and had greater body mass index, blood pressure, fasting and postload glucose, insulin, HOMA index, LV mass, and left atrial diameter than patients with preserved diastolic function. Variables of diastolic function measured at TDI were significantly related with age, body mass index, LV mass, and fasting and postload plasma glucose. Stepwise regression analysis showed that the relationship of markers of diastolic dysfunction with both fasting and postload glucose levels was independent of possible confounders.
CONCLUSIONS:
Initially abnormal fasting and postload glucose levels are associated with more prominent diastolic impairment in uncomplicated hypertensive patients, suggesting that hyperglycemia might increase the risk of diastolic heart failure even in the absence of diabetes
Early renal failure as a cardiovascular disease: Focus on lipoprotein(a) and prothrombotic state
No full textPatients with renal failure are at increased risk of cardiovascular events even at the earliest stages of disease. In addition to many classic cardiovascular risk factors, many conditions that are commonly identified as emerging risk factors might contribute to occurrence of cardiovascular disease. Changes in circulating levels of many of these emerging risk factors have been demonstrated in patients with early stages of renal failure caused by different types of renal disease and have been associated with detection of cardiovascular complications. However, for most of these factors evidence of benefits of correction on cardiovascular outcome is missing. In this article, we comment on the role of lipoprotein(a) and prothrombotic factors as potential contributors to cardiovascular events in patients with early renal failure
Salt, hypertension, and cardiovascular disease
No full textIntervention on lifestyle has been suggested as a cost-effective strategy on prevention and treatment of hypertension. In this commentary, we focus on the evidence supporting a role of dietary salt consumption in blood pressure control and development of cardiovascular disease discussing the findings of some recent studies. Current evidence indicates a continuous relationship between dietary salt and blood pressure and, despite that this relationship appears to be limited to subjects with highest salt intake, this evidence supports the benefits of appropriate salt intake reduction. Conversely, evidence of possible benefits of dietary salt reduction on cardiovascular outcomes remains unproved and will require further investigation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Microalbuminuria and plasma aldosterone levels in nondiabetic treatment-naïve patients with hypertension
No full textOBJECTIVES: Identification of factors that contribute to urinary albumin losses in hypertensive nephropathy is crucial for prevention of renal deterioration. The aim of this study was to investigate the relationship of low-grade albuminuria with plasma aldosterone levels in treatment-naïve hypertensive patients free of additional comorbidities that might affect renal function.
METHODS: In 242 newly diagnosed patients with uncomplicated primary hypertension, we obtained duplicate 24-h urine collections for measurement of urinary albumin/creatinine ratio (UACR) and measured plasma aldosterone levels. Patients with diabetes, overt proteinuria (>300 mg/day), glomerular filtration rate less than 30 ml/min per 1.73 m, and previous renal diseases were excluded.
RESULTS: Increasing UACR was associated with significantly and progressively higher blood pressure (BP), HDL-cholesterol, and plasma aldosterone levels, and with lower glomerular filtration. Microalbuminuria (30-300 mg/day) was detected in 41 (17%) of 242 hypertensive patients, and these patients had significantly higher BP and plasma aldosterone levels (178 ± 113 vs. 128 ± 84 pg/ml; P = 0.001), and lower glomerular filtration than patients without microalbuminuria. UACR was directly and independently correlated with BP and plasma aldosterone levels. In a logistic regression model, presence of microalbuminuria was associated with plasma aldosterone levels independently of glomerular filtration and demographic, anthropometric, and metabolic variables.
CONCLUSION: In nondiabetic, treatment-naïve patients with hypertension, low-grade albuminuria is independently associated with elevated plasma aldosterone. These findings suggest a contribution of aldosterone to the early glomerular changes occurring in hypertensive nephropathy
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
