Hypertension and nephrology - 2011;15(01)

Hypertension and nephrology

FEBRUARY 28, 2011

[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.]

Hypertension and nephrology

FEBRUARY 28, 2011

[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

FEBRUARY 28, 2011

[Direct renin inhibitors]

FARSANG Csaba

[The mechanisms of action of direct renin inhibitors and the important clinical findings gained by the first, clinically approved drug, aliskiren are discussed. The relative lack of side effects and the very long-lasting antihypertensive action of aliskiren is emphasized. Investigations showing efficacy and protective effects of aliskiren and its combinations with other antihypertensive drugs (diuretics, calcium antagonists, angiotensin converting enzyme inhibitors, angiotensin receptor blockers) against hypertension-induced subclinical organ damage as well as still ongoing clinical trials are also described.]

Hypertension and nephrology

FEBRUARY 28, 2011

[Importance, prevalence and therapy of vitamin D deficiency]

SZABÓ András

[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.]

Hypertension and nephrology

FEBRUARY 28, 2011

[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

FEBRUARY 28, 2011

[Combination of diuretics in resistant hypertension]

RADÓ János

[Resistant hypertension developed in a 60-year-old male patient with chronic renal insufficiency due to untreated high blood pressure for decades despite of the coadministration of furosemide, β-blocker, calcium channel blocker, angiotensin converting enzyme inhibitor and angiotensin receptor blocker. Breakthrough could be achieved by the combination of a tiazide compound and a loop diuretic (furosemide). It seemed to be worthwile publishing the case because the tiazide drug could be successfully administered below 30 ml/min GFR, where it is generally thought to be ineffective, and because both elements of the combination was given in very low doses relative to the kidney disease. The literature of the most important combinations of the tiazide preparations and the loop diuretics are reviewed and some historical aspects are given as well.]