Background/Aims: Arterial stiffening characterizes the vasculature of end-stage renal disease (ESRD) patients and is a strong predictor of their cardiovascular morbidity and mortality. Previous studies evaluating the effect of hemodialysis on large artery elasticity gave contradictory results. This study aimed to investigate the impact of hemodialysis on arterial stiffness and wave reflections on chronic hemodialysis patients. Methods: A total of 51 stable ESRD patients on maintenance hemodialysis were evaluated before and after the first and second dialysis session of the week. Arterial stiffness was assessed by measuring aortic and brachial pulse wave velocity (PWV). Central arterial pressure waveform parameters were estimated by radial artery applanation tonometry. Heart rate-adjusted augmentation index [AIx(75)] was used as measure of wave reflections. Results: During both dialysis sessions systolic blood pressure (SBP) and pulse pressure (PP) at brachial artery and central aorta were reduced. AIx(75) was decreased in first and second weekly dialysis session (27.5 ± 1.2 vs. 21.0 ± 1.5, p < 0.001 and 24.7 ± 1.2 vs. 20.5 ± 1.5, p < 0.001, respectively). In contrast, aortic and brachial PWV remained unchanged during both dialysis sessions. Changes in AIx(75) during hemodialysis were associated with changes in central aortic SBP, PP and ejection duration. Conclusions: This study shows that hemodialysis does not acutely affect arterial stiffness, but reduces wave reflections from periphery. This dissociation between effects of hemodialysis on PWV and AIx(75) may reflect differential impact on large and small branches of the arterial tree.

Agents such as sodium nitroprusside, nitroglycerin and hydralazine have been used for many years as first-line options for patients with hypertensive emergencies, although their potential adverse effects and difficulties in use were well known. With time, equally potent and less toxic alternatives, including nicardipine, fenoldopam, labetalol and esmolol are increasingly used worldwide. Recently, clevidipine, a third-generation dihydropyridine calcium-channel blocker with unique pharmacodynamic and pharmacokinetic properties was added to our therapeutic armamentarium and was shown in clinical trials to reduce mortality when compared with nitroprusside. In view of such evidence, a change in pharmacological treatment practices for hypertensive crises toward newer and safer agents is warranted.

Vitamin D deficiency is common in the developing countries and exists in both childhood and adult life. The great importance of Vitamin D is the moderation of calcium (Ca) and phosphorus (P) homeostasis as well as the absorption of Ca. While insufficiency of vitamin D is a significant contributing factor to risk of rickets in childhood, it is possible that a more marginal deficiency of vitamin D during life span contribute to osteoporosis as well as potentially to the development and various other chronic diseases such as cardiovascular disease, cancer and diabetes. This paper reviews the metabolism, epidemiology, and treatment of vitamin D and calcium insufficiency as well as its relation to various diseases during childhood and adolescence.