1.
Severe catabolic state after an overnight fast in patients with chronic renal failure.
Nakaya, Y, Shimohata, T, Haraguchi, S, Nakao, T, Minaguchi, J, Sumitani, H, Harada, N, Sakaue, H
Nutrition (Burbank, Los Angeles County, Calif.). 2011;(3):329-32
Abstract
OBJECTIVE Starvation causes more rapid development of a catabolic state in patients with liver cirrhosis than in normal subjects. Because the kidneys have a gluconeogenic activity similar to that of the liver, we tested whether patients with chronic renal failure develop a catabolic state after an overnight fast. METHODS The effect of an overnight fast on diurnal changes in respiratory quotient (RQ) was studied in 12 normal subjects and 12 patients with stable chronic renal failure. Changes in RQ in the early morning after an overnight fast were also studied in 27 patients with chronic renal failure not on dialysis. We also examined the effect on RQ of consuming a light snack in the evening before the measurements. RESULTS The RQ before breakfast, but not at other times, was significantly lower in patients with renal failure than in normal subjects (0.824 ± 0.051 versus 0.868 ± 0.038, P < 0.05). This indicated that patients with renal failure had higher fat use and developed a catabolic state early in the morning. The RQ before breakfast showed significant inverse correlations with creatinine levels (r = -0.604, P < 0.001). Supplementation with a carbohydrate-rich snack in the evening resulted in a significant increase of 0.07 ± 0.04 (P < 0.05) in mean RQ in the early morning. This suggested that a late evening snack is useful for improving the catabolic state of patients with renal failure. CONCLUSION Starvation involving an overnight fast facilitates catabolism of visceral and muscle proteins in renal failure. This suggests that nutritional management of renal failure should focus not only on the contents of a meal, but also on the timing of the meal.
2.
Iso-osmolality versus low-osmolality iodinated contrast medium at intravenous contrast-enhanced CT: effect on kidney function.
Nguyen, SA, Suranyi, P, Ravenel, JG, Randall, PK, Romano, PB, Strom, KA, Costello, P, Schoepf, UJ
Radiology. 2008;(1):97-105
Abstract
PURPOSE To determine the effects of iso-osmolality contrast medium compared with a low-osmolality agent on renal function (serum creatinine [SCr] and glomerular filtration rate [GFR]) in high-risk patients undergoing intravenous contrast material-enhanced CT. MATERIALS AND METHODS This HIPAA-compliant study was IRB-approved; formal consent was obtained. One hundred seventeen patients (83 men, 34 women; mean age, 64.3 years; range, 18-86 years) with decreased renal function underwent contrast-enhanced CT with either iso-osmolality iodixanol (n = 61) or low-osmolality iopromide (n = 56). Outcome measures were of SCr increase or GFR decrease for 3 days after CT, a SCr increase (of >or=0.5 mg/dL [44.2 micromol/L, 25%] or >or=1.0 mg/dL [88.4 micromol/L, 50%]), a GFR reduction (of >or=5 mL/min), and patient outcome at 30- and 90-day follow-up. RESULTS Iodixanol decreased SCr (mean +/- standard deviation) from 1.77 mg/dL +/- 0.24 (156.47 micromol/L +/- 21.22) at baseline to 1.65 mg/dL +/- 0.35 (145.86 micromol/L +/- 30.94, P = .046) at day 1, 1.73 mg/dL +/- 0.53 (152.93 micromol/L +/- 46.85, not significant) at day 2, and 1.73 mg/dL +/- 0.55 (152.93 micromol/L +/- 48.62, not significant) at day 3 (not significant). Iopromide increased SCr from 1.75 mg/dL +/- 0.32 (154.7 micromol/L +/- 28.29) at baseline to 1.8 mg/dL +/- 0.42 (159.12 micromol/L +/- 15.59) at day 1, 1.77 mg/dL +/- 0.49 (156.47 micromol/L +/- 43.32) at day 2, and 1.77 mg/dL +/- 0.62 (156.47 micromol/L +/- 54.81) at day 3 (not significant). Iodixanol increased and iopromide decreased GFR on all 3 days after CT (not significant). Fewer patients in the iodixanol group (8.5%) than in the iopromide group (27.8%) had SCr increase 0.5 mg/dL or higher (>or=25%, P = .012). Two patients in each group had SCr increase of 1.0 mg/dL or more (not significant). More patients in the iopromide group (42.3%) than in the iodoxanol group (24.1%) had a GFR reduction of 5 mL/min or higher (P = .0426). No patient had a contrast material-related adverse event at 30- or 90-day follow-up. CONCLUSION Intravenous contrast material application in high-risk patients is unlikely to be associated with permanent adverse outcomes. SCr levels after contrast material administration are lower in iodixanol than iopromide groups.
3.
Serum cystatin C-based equation compared to serum creatinine-based equations for estimation of glomerular filtration rate in patients with chronic kidney disease.
Hojs, R, Bevc, S, Ekart, R, Gorenjak, M, Puklavec, L
Clinical nephrology. 2008;(1):10-7
Abstract
Estimation of the glomerular filtration rate (GFR) is essential for the evaluation of patients with chronic kidney disease (CKD). The Cockcroft-Gault (CG) and modification of diet in renal disease (MDRD) formulas are serum creatinine-based equations, and the most widely used tests for renal function. Recently, serum cystatin C-based equations were proposed as markers for estimation of GFR. The present study compares our serum cystatin C-based equation (cystatin C formula) and serum creatinine-based equations for a large group of patients with CKD. In this study, 592 adult patients with CKD were enrolled. In each patient, serum creatinine was determined and creatinine clearance was calculated using the CG and MDRD formulas. The serum cystatin C was determined by an immunonephelometric method and our own cystatin C formula (GFR = 90.63 x cystatin C-1.192) for estimation of GFR was developed. GFR was measured using 51CrEDTA clearance, and the correlation, accuracy, bias and precision were determined. Ability to correctly estimate the patient's GFR with different equations compared to gold standard below and above 60 ml/min/1.73 m2; was analyzed. The mean 51CrEDTA clearance was 47 ml/min/1.73 m2, the mean serum creatinine was 269 micromol/l and the mean serum cystatin C was 2.68 mg/l. Statistically significant correlation between 51CrEDTA clearance with the CG (r = 0.861) and MDRD (r = 0.909) formulas and the cystatin C formula (r = 0.899) was found. The receiver operating characteristic (ROC) curve analysis (cut-off for GFR 60 ml/min/1.73 m2) showed that the cystatin C formula had a significantly higher diagnostic accuracy than the CG formula (p < 0.003). All equations underestimated the measured GFR and lacked precision. Analysis of ability to correctly predict the patient's GFR below or above 60/ml/min/1.73 m2 showed a higher prediction for the cystatin C formula than the MDRD formula (91.6 versus 84.1%, p < 0.0005) and a higher prediction trend than the CG formula (91.6 versus 88.3%, p = 0.078). Our results indicate that serum cystatin C-based equation is a reliable marker of GFR with a very high diagnostic accuracy and ability to predict patients with CKD and GFR under 60/ml/min/1.73 m2.
4.
Creatininuria in asthmatic children treated with a combination of glucocorticoid and beta-agonist.
Giroux, M, Ferrières, J
The Journal of asthma : official journal of the Association for the Care of Asthma. 2003;(1):41-8
Abstract
We examined whether a combination of glucocorticoids and beta-agonists inhaled by asthmatics had an influence on the metabolism of L-arginine, an amino acid involved in the production of urea, creatinine, and NO that is known to play a significant role in asthma. After lung function tests, we assayed nitrates, urea, and creatinine and determined urinary osmolality in urine samples taken from groups of 129 children (10+/-3 years old) with mild-to-moderate asthma treated with different regimens of drugs. No significant differences in urinary urea levels were noted between the groups. On the other hand, the children treated by the combination of glucocorticoid and beta-agonist (n = 52) had a higher level of urinary creatinine (+40%, P < .001, and a higher creatinine/urea ratio (C/U) expressed as % mass= 5.98 +/- 2.44, P < .001) than did the untreated children (n = 43, C/U = 4.03 +/- 1.24), those treated with glucocorticoid (n = 23, C/U = 4.01 +/- 1.32) or beta-agonist alone (n = 11, C/U = 4.09 +/- 1.01) or control children of the same age (n = 20, C/U = 4.81 +/- .90). Children treated with beta-agonist alone had the lowest mean levels of urinary nitrates (P < .05). The children in group 1 whose C/U ratio was above 6 (n = 24) had a higher FVC (P < .02) and FEV1 (not significant (NS)). However, an overly high C/U may also be indicative of a deleterious influence on the biosynthesis of NO from arginine. Further investigations will be required to determine whether there is a relationship between C/U ratios and lung function parameters, and whether the urinary C/U ratio could be employed as a simple and noninvasive parameter for assessment of treatment in asthmatics.