Hypertension and nephrology

[Importance, prevalence and therapy of vitamin D deficiency]

SZABÓ András

FEBRUARY 28, 2011

Hypertension and nephrology - 2011;15(01)

[Annual citations in the PubMed database on vitamin D were approximately 5000, this represents a doubling in the last decade and a 20% increase in the last year. There is renewed interest in vitamin D synthesis, metabolism and action. The two principal reasons for increased interest can be: 1. new knowledge regarding the nonhormonal, autocrine, and paracrine actions of 1,25-dihydroxylated vitamin D metabolites in man, 2. the worsening, worldwide trend to vitamin D insufficiency. Clinical vitamin D research in last years has confirmed the presence of a worldwide problem of vitamin D depletion, a problem that appears to be worsening. Largescale population based studies bear out long-held concerns that low serum 25(OH)D levels are associated with a number of adverse outcomes in the human musculoskeletal, innate immune, and cardiovascular systems. In fact, low vitamin D levels are significantly associated with all-cause mortality in the U.S. population and Hungary respectively. It is hypothesized that the global rise in incidence of obesity contributes to the worsening of the problem of vitamin D deficiency, amplifying adverse impacts on the host skeleton, immunoreactivity to microbes, and metabolic status. Finally, it should be remembered that treatment of vitamin D deficiency has two phases: restoration of 25(OH)D levels up to more than 30 ng/ml; and maintenance of the serum 25(OH)D level in that range. The present upper level (UL) of vitamin D intake that is deemed to be safe (2000 IU/day) must be re-evaluated considering data acquired over the past 15 years.]

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Further articles in this publication

Hypertension and nephrology

[Scylla and Charybdis - the treatment of hypertension]

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Hypertension and nephrology

[The clinical significance of peripheral and central blood pressure form the neurologist’s point of view]

BERECZKI Dániel, VASTAGH Ildikó

[Hypertension - affecting both the large and the small cerebral vessels - is the most frequent risk factor for cerebrovascular disorders manifesting in stroke, hypertensive encephalopathy or vascular dementia. The central pressure measured at the proximal part of the aorta has more important role in the development of vascular hypertrophy and carotid atherosclerosis than the pressure measured in the brachial artery. Central aortic pressure more accurately reflects the filling conditions of the left ventricle and thus the pressure conditions affecting the cerebral vascular system, than brachial pressure values, therefore possibly predicts more reliably the risk of cardiovascular events than brachial pressure values. Features of the stiffness of large arteries (like pulse wave velocity) more directly reflect the chronic effect of ageing, hypertension and diabetes than brachial or even central aortic pressure. Therefore in upcoming clinical trials arterial stiffness and central aortic pressure should be considered as possible surrogate endpoints. Antihypertensive treatment is an important part of primary and secondary stroke prevention. Decreasing blood pressure in hypertensive subjects significantly decreases the risk of stroke and other vascular events, and the extent of risk reduction primarily depends on the extent of the decrease in blood pressure. Several factors should be considered when choosing from treatment options. The use of traditional β blockers - partly due to their smaller effects on central blood pressure - decreased recently. Further observations will decide on the role of third generation β blockers in the prevention of cardiovascular mortality and morbidity.]

Hypertension and nephrology

[The importance of epithelial-mesenchymal transition in kidney fibrosis]

NAGY SZAKÁL Dorottya, SZEBENI Beáta, SZIKSZ Erna, HIMER Leonóra, REUSZ György, VÁSÁRHELYI Barna, TULASSAY Tivadar, VANNAY Ádám

[Epithelial-mesenchymal transition (EMT) plays a central role in physiological and pathological processes of embryogenesis, carcinogenesis and tissue fibrosis. During EMT epithelial cells may transform to myofibroblasts, which are the effector cells of fibrosis. In our summary the process of EMT and its medical importance will be reviewed in relation to renal fibrosis. Regardless of the initiating cause the final common mechanism of organ fibrosis is similar in the different chronic renal diseases. It always involves major inflammatory responses, however the molecular mechanisms involved are still elusive. The EMT now takes centre stage as the point of convergence between inflammation and the progression of degenerative fibrotic diseases. Understanding the pathomechanism of EMT and the significance of signalling pathways involved in this process may lead to a new therapeutic approach in the treatment of chronic renal diseases.]

Hypertension and nephrology

[News of the Hungarian Society of Nephrology]

Hypertension and nephrology

[The effect of antihypertensive drugs on central blood pressure]

PÁLL Dénes, KOMONYI Éva, LENGYEL Szabolcs, PARAGH György, KATONA Éva

[It is well known, that there is a difference between peripheral and central systolic and pulse pressure. As the pressure wave travels distally from the heart, there is a significant increase, which is called pressure amplification. Central blood pressure can be measured easily and non-invasively, and the result shows a positive correlation with cardiovascular end-points. Several antihypertensive drugs can differently decrease central and peripheral blood pressure. The effect of diuretics on central systolic and pulse pressure is neutral or negative. While traditional β-blockers (e.g. atenolol) have a definitive negative effect, nebivolol shows a positive one. The calcium antagonists tend to have a favorable effect, while the clear beneficial effect of the angiotensin converting enzime inhibitors is well documented. There are only few data on angiotensin receptor blockers, however, the results seem to be promising.]

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Risk factors for ischemic stroke and stroke subtypes in patients with chronic kidney disease

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Background - The aim of this study was to compare ischemic stroke subtypes with the effects of risk factors, the relationship between grades of kidney disease and the severity of stroke subtypes. Methods - The current study was designed retrospectively and performed with data of patients who were hospitalised due to ischemic stroke. We included 198 subjects who were diagnosed with ischemic stroke of Grade 3 and above with chronic kidney disease. Results - In our study were reported advanced age, coronary artery disease, moderate kidney disease as the most frequent risk factors for cardioembolic etiology. Hypertension, hyperlipidemia, smoking and alcohol consumption were the most frequent risk factors for large-artery disease. Female sex and anaemia were the most frequent risk factors for small-vessel disease. Dialysis and severe kidney disease were the most frequent risk factors in unknown etiologies, while male sex, diabetes mellitus, prior stroke and mild kidney disease were the most frequent risk factors for other etiologies. National Institute of Health Stroke Scale (NIHSS) scores were lower for small-vessel disease compared with other etiologies. This relation was statistically significant (p=0.002). Conclusion - In order to improve the prognosis in ischemic stroke with chronic kidney disease, the risk factors have to be recognised and the treatment options must be modified according to those risk factors.

Hypertension and nephrology

[Prognostic role of arterial stiffness in IgA nephropathy]

SÁGI Balázs, KÉSŐI István, VAS Tibor, CSIKY Botond, KOVÁCS Tibor, NAGY Judit

[Background: Arterial stiffness has a prognostic role in chronic cardiovascular diseases. Pulse wave velocity (PWV) determined by the carotid-femoral pulse detection is accepted as a gold standard method. Further diagnostic procedures are in use to assess the arterial stiffness including the finger photoplethysmography. The prognostic role of this method is limited in chronic renal diseases. The goal of our investigation was to determine the prognostic significance of the stiffness index (SIDVP) measured by the photoplethysmographic method in IgA nephropathy. Patients and methods: One hundred and three histologically proved IgA nephropathy patients with chronic kidney disease stage 1-4 were investigated (67 male, 36 female, 45 ± 11 years) and followed for an average 65 (6-107) months. The stiffness index was determined by the volume alteration of the digital artery during the cardiac cycle (Pulse Trace system, Micro Medical, Gilingham, Kent, UK). The primary combined end point was total mortality, major cardiovascular events (stroke, myocardial infarction or cardiovascular procedure, for example revascularisation) plus achieving end stage renal disease. The secondary end points were cardiovascular and renal end points alone. Results: The patients with increased stiffness index (> 10 m/s) had significantly more combined primary end point events (10/60 vs. 19/43, P = 0.015). In case of the secondary end points the renal end points were significantly more frequent in patients with higher stiffness index. Stiffness index has also proved to be an independent predictor on survival from other cardiovascular risk factors (age, hypertension, diabetes, obesity, lipid disturbances and decrease of renal function) using the Cox regression model in IgA nephropathy. Every 1 m/s increase in stiffness index resulted a 17% gain in the occurrence of the combined primary end point. Conclusions: Stiffness index determined by finger photoplethysmography is an eligible parameter to assess the prognosis in IgA nephropathy. Increased stiffness index in IgA nephropathy seems to be a good prognostic tool for identification of higher risk patients.]

Hypertension and nephrology

[Restless legs syndrome in patients with chronic kidney disease]

LINDNER Anett, FORNÁDI Katalin, MOLNÁR Miklós Zsolt

[The aging of the population, the high prevalence of chronic diseases and the consequent rapid increase of healthcare expenditures present a difficult challenge for the medical care system and for the society in the developed countries. Sleep disorders are increasingly recognized as very frequent chronic diseases with significant pathophysiological and psychosocial consequences. In the last 20 years an increasing number of studies reported high prevalence of sleep disorders, such as restless legs syndrome in patients with kidney disease. Chronic renal failure is the most common condition presenting with secondary restless legs syndrome. It is associated with insomnia, depressive symptoms and anxiety, impaired quality of life, as well as elevated cardiovascular risk. Compliance of the patients with restless legs syndrome is decreased, and it is more likely that they discontinue dialysis treatment. This may be related to higher mortality in kidney disease patients with restless legs syndrome.]

LAM Extra for General Practicioners

[The impact of vitamin D in infertility and the role in pregnancy and in nursing period]

SPEER Gábor

[Various medical associations issue different recommendations for the prevention and treatment of vitamin D deficiency. These significant differences are partly explained by the different definition of normal vitamin D level and the use of completely different mathematical models to predict the increase in vitamin D level as a response to therapy. According to the Institute of Medicine, the target vitamin D level is 20 ng/ml, whereas the Endocrine Society recommends 30 ng/m as the minimum target value. These differences show that the two Society have different views on the risk of adverse effects. Screening, however, is not recommended by either society. In this review I summarize the role of the vitamin D supplementation in the prevention of infertility. Also, I suggest the protective effect of the vitamin D during the pregnancy. In my opinion screening program against D hypovitaminosis should be performed in case of infertility and in pregnancy, because data show a protective role of vitamin D against many disease of newborn. ]

Hypertension and nephrology

[Fructose-induced hyperuricaemia]

NAGY Judit, KISS István, WITTMANN István, KOVÁCS Tibor

[The consumption of fructose and fructose-based sweeteners has dramatically increased in the last hundred years and correlates epidemiologically with the rising prevalence of obesity, hypertension and metabolic syndrome worldwide. The administration of fructose to animals and humans increases uric acid generation independently from excessive caloric intake. Fructose ingestion may also be a risk factor of chronic kidney disease, that includes glomerular hypertension, vascular alterations (arteriolosclerosis) and albuminuria. The discovery that fructose-mediated generation of uric acid may have a casual role in metabolic syndrome and kidney disease provides new insight into pathogenesis and therapies for these important diseases.]