Short-term growth hormone treatment and microcirculation: effects in patients with chronic kidney disease.

Endothelial dysfunction is common in patients with chronic kidney disease (CKD) and contributes significantly to the high long-term cardiovascular morbidity and mortality. The short-term cardiovascular effects of recombinant human growth hormone (rhGH) in CKD patients (stages III-V) and healthy controls (n=15 each) were explored in a single-center, non-randomized pilot study. Subjects were investigated before, after a 7 day treatment with rhGH, and after a 7 day wash-out period. Microcirculation was assessed by nailfold capillaroscopy and leg strain gauge plethysmography. Echocardiography was performed and serum concentrations of IGF-I and IGF-binding protein-3 (IGFBP-3) were determined. Before the start of rhGH therapy, mean post-ischemic maximum flow velocity of erythrocytes (V(RBC)) and leg blood flow (LBF) in CKD patients were significantly reduced to 68% and 75% of that seen in controls, whereas V(RBC) and LBF under resting conditions were comparable. Treatment with rhGH significantly increased V(RBC) and LBF under resting conditions. Whereas maximum post-ischemic V(RBC) was improved by rhGH in patients and controls, maximum post-ischemic LBF increased in controls only. This was paralleled by a non-significant reduction of total vascular resistance, and increased heart rate and cardiac index. In conclusion, CKD patients respond to short-term rhGH treatment with significantly improved capillary blood flow, whereas only minor effects on total peripheral resistance and cardiac output were noted.

Renal Insufficiency Following Radiocontrast Exposure Trial (REINFORCE): a randomized comparison of sodium bicarbonate versus sodium chloride hydration for the prevention of contrast-induced nephropathy.

INTRODUCTION: For the prevention of contrast-induced nephropathy (CIN) after coronary angiography, hydration by 0.9% sodium chloride solution and N-acetylcysteine is currently recommended. However, it is unclear whether volume supplementation with sodium bicarbonate is better than with sodium chloride when used in conjunction with nonionic, low-osmolar iopamidol. The aim of this study was to analyze and compare the effects of sodium bicarbonate and sodium chloride on renal function in 145 patients exposed to nonionic iso-osmolar contrast medium iodixanol in a randomized study. PATIENTS AND METHODS: Renal Insufficiency Following Radiocontrast Exposure is a prospective, randomized, single-center, double-blinded trial of 145 patients (age 72.6+/-6.7 years) with elevated baseline serum creatinine levels (mean 132.6+/-29.3 micromol/l). Eligible patients were randomized to either a 154 mEq/l infusion of sodium bicarbonate (n=71, group I) or sodium chloride 0.9% solution (n=74, group II). The primary endpoint was serum creatinine elevation beyond 25% or 44 micromol/l on the first or second day following exposure to the contrast medium. Serum creatinine, serum cystatin C, plasma viscosity, urinary enzymes alanine aminopeptidase and N-acetyl-beta-D-glucosaminidase, and alpha1-microglobulin were measured at baseline and on days 1 and 2 after contrast medium administration. RESULTS: An overall proportion of five CIN (3.4%) was observed with equal distribution among the groups (4.2% in sodium bicarbonate group vs. 2.7% in sodium chloride group; P=0.614). Parameters of renal function demonstrated no differences between the two hydration regimens on day 1 after angiography; even on day 2 most parameters were similar in groups I and II. CONCLUSION: Renal Insufficiency Following Radiocontrast Exposure demonstrates a homogeneously low rate of CIN after exposure to nonionic, iso-osmolar iodixanol regardless of the use of either bicarbonate sodium or sodium chloride solution for volume supplementation. Low-toxicity contrast media and any hydration may offset potential antioxidant effects of sodium bicarbonate.