Search

The study attempts to evaluate the efficacy of percutaneous revascularization of the renal artery as a form of treatment for artherosclerotic renovascular disease. The results indicate that such a form of treatment increased the risks rather than providing any benefits.

On completion of this article you should be able to (1) identify the 3 forms of renal damage that can cause an elevated serum creatinine level, (2) develop a plan [...]

Introduction Exposure concentrations assessed from spot urine samples are typically adjusted to a constant creatinine concentration to correct for dilution of the samples due to the variable hydration status of [...], Introduction: A commonly used approach to adjust for urine dilution in analyses of biomarkers is to adjust for urinary creatinine. However, creatinine is a product of muscle mass and is therefore associated with body mass. In studies of urinary analytes and obesity or obesity-related outcomes, controlling for creatinine could induce collider stratification bias. We illustrate this phenomenon with an analysis of urinary arsenic. Objective: We aimed to evaluate various approaches of adjustment for urinary dilution on the associations between urinary arsenic concentration and measures of obesity. Methods: Using data from the National Health and Nutrition Examination Survey, we regressed body mass index (BMI) and waist-to-height ratios on urinary arsenic concentrations. We compared eight approaches to account for urine dilution, including standardization by urinary creatinine, osmolality, and flow rates, and inclusion of these metrics as independent covariates. We also used a recently proposed method known as covariate-adjusted standardization. Results: Inverse associations between urinary arsenic concentration with BMI and waist-to-height ratio were observed when either creatinine or osmolality were used to standardize or as covariates. Not adjusting for dilution, standardizing or adjusting for urinary flow rate, and using covariate-adjusted standardization resulted in null associations observed between arsenic concentration in relation to BMI and waist- to-height ratio. Conclusions: Our findings suggest that arsenic exposure is not associated with obesity, and that urinary creatinine and osmolality may be colliders on the causal pathway from arsenic exposure to obesity, as common descendants of hydration and body composition. In studies of urinary biomarkers and obesity or obesity-related outcomes, alternative metrics such as urinary flow rate or analytic strategies such as covariate-adjusted standardization should be considered. https://doi.org/10.1289/EHP1202

Byline: Frederique Ryckwaert (1,4), Pierre Alric (2), Marie-Christine Picot (3), Kela Djoufelkit (3), Pascal Colson (1,4) Keywords: Abdominal infrarenal aortic surgery; Postoperative renal failure; Mortality; Morbidity; Renal dysfunction; Renal failure Abstract: Objective To evaluate the incidence and the circumstances of a moderate increase in serum creatinine early after elective abdominal aortic surgery. Design Prospective clinical observational study. Setting Surgical intensive care unit in a university hospital. Patients Two hundred and fifteen consecutive adult patients operated on for infra-renal abdominal aortic surgery during 1 year. Interventions A moderate increase in plasma creatinine of 20% from preoperative value (renal dysfunction, RD) was systematically recorded during the first 3 days following surgery. Organ dysfunctions (cardiac, pulmonary, haematological, and neurological) were assessed. Measurements and results Forty-three patients (20%) experienced a postoperative RD six of these required dialysis. RD was associated with other organ dysfunctions in 60.5% patients. Mortality rate was significantly higher for patients who had a RD, than patients without RD (9.3% vs 1.2%, P Conclusion Our results suggest that a postoperative 20%-increase in plasma creatinine after abdominal aortic surgery is not rare and occurs frequently with other organ dysfunction. Author Affiliation: (1) Department of Anesthesiology and Intensive Care, Hopital Arnaud de Villeneuve, avenue du Doyen Giraud, 34295 , Montpellier, France (2) Department of Thoracic and Vascular Surgery, Hopital Arnaud de Villeneuve, Montpellier, France (3) Department of Biostatistics, Hopital Arnaud de Villeneuve, Universite Montpellier I, Montpellier, France (4) INSERM U 469, CCIPE, 34295, Montpellier, France Article History: Received Date: 08/04/2002 Accepted Date: 16/07/2003 Online Date: 27/08/2003

Byline: Hiroshi Morimatsu (1), Shigehiko Uchino (1), John Chung (2), Rinaldo Bellomo (1), Jai Raman (2), Brian Buxton (2) Keywords: Norepinephrine; Cardiac surgery; Creatinine; Acute renal failure; Shock; Cardiopulmonary bypass Abstract: Objectives Norepinephrine use in patients after cardiac surgery is controversial because of the fear that norepinephrine might decrease kidney function through regional vasoconstriction. Accordingly, we studied the renal effects of norepinephrine use for hypotensive vasodilatation after cardiac surgery. Design and setting Retrospective controlled study in the cardiothoracic ICU of tertiary hospital. Patients 100 cardiac surgery patients with post-operative hypotensive vasodilatation and 100 control cardiac surgery patients. Intervention Treatment of hypotension (MAP Measurements and results We collected data on demographic and surgical characteristics, haemodynamics, serum creatinine and mortality. Just after surgery the norepinephrine group had a significantly higher mean central venous pressure, lower mean arterial pressure, and lower systemic vascular resistance index with a similarly elevated mean cardiac index. Despite norepinephrine administration at a mean peak dose of 7.3+-6.4 Aug/min the mean post-operative change in creatinine was not different between two groups on days 0, 2 or 4 after surgery. Conclusions Norepinephrine does not increase post-operative serum creatinine concentrations in patients with hypotensive vasodilatation after cardiac surgery. Concerns related to its potential adverse effects on the kidney function in this setting appear unjustified. Author Affiliation: (1) Departments of Intensive Care and Medicine, Austin and Repatriation Medical Centre, Melbourne University, Studley Road, Heidelberg, 3084, Melbourne, Victoria, Australia (2) Department of Cardiothoracic Surgery, Austin and Repatriation Medical Centre, Studley Road, Heidelberg, 3084, Melbourne, Victoria, Australia Article History: Received Date: 10/10/2002 Accepted Date: 14/04/2003 Online Date: 22/05/2003 Article note: This study was supported by the Austin and Repatriation Medical Centre Intensive Care Research Fund

Byline: S. Hellerstein (1), Stephen D. Simon (1), Max Berenbom (1), P. Erwin (1), Ellen Nickell (1) Keywords: KeywordsaCreatinine excretion rate; Creatinine clearance; Cimetidine; Chronic renal failure; Timed-urine collections Abstract: A total of 637 timed-urine collections for creatinine excretion rates obtained from 295 children over 14 years have been analyzed. The children ranged in age from 2.8 to 21.7 years at the time of the clearance study. The data analyzed included only one study from a child during any 6-month period. The objective is to provide data defining the expected range of creatinine excretion for renal clearance studies. One hundred forty-two studies were conducted on children not pretreated with cimetidine and 495 on those pretreated with cimetidine. Analysis showed that pretreatment with cimetidine for creatinine clearance studies does not alter creatinine excretion rates (P=0.080 95% CI --0.03 to 1.61). Creatinine excretion rates in urine collections obtained at home (roughly 24-h collections) were compared with 2-h supervised collections in the Children's Kidney Center. The supervised urine collections resulted in creatinine excretion rates 1.38 mg/kg/24 h greater than home collections (P=0.001 95% CI 0.76--2.00). Using regression equations for creatinine excretion rate with age, tables have been prepared showing the expected rate of creatinine excretion for renal clearance studies in children 3--21 years of age. Author Affiliation: (1) Sections of Nephrology and Medical Research, The Children's Mercy Hospital, The University of Missouri at Kansas City School of Medicine, 2401 Gillham Road, Kansas City, MO 64108, USA Tel.: +1-816-2343010, Fax: +1-816-2343494, US Article note: Received: 7 December 2000 / Revised: 20 March 2001 / Accepted: 22 March 2001

Byline: Z. Molnar (1), K. L. MacKinnon (2), E. Shearer (1), D. Lowe (3), I. D. Watson (2) Abstract: Objective: To investigate the effects of N-acetylcysteine (NAC) when given as an early treatment to critically ill patients on the serum total anti-oxidant potential (TAP) and urine micro-albumin : creatinine (M : Cr) ratio. Design: Prospective, placebo controlled, double blinded clinical trial. Setting: General intensive care unit in a teaching hospital. Patients: Sixty critically ill patients were recruited but ten were withdrawn due to less than 48 h of ICU stay. Interventions: After envelope randomisation, patients received either NAC (n = 23): a bolus of 150 mg/kg in 250 ml of 5 % dextrose followed by a continuous infusion of 12 mg/kg per h in 500 ml of 5 % dextrose over 24 h or, as controls (n = 27), the equal volume of placebo. Treatment lasted for a minimum of 3, up to a maximum of 5, days. Blood and urine samples were collected on admission (0 h) and then 6 hourly up 18 h. Measurements and results: There was no significant difference between NAC and placebo groups regarding the required length of inotropic support, mechanical ventilation and ICU stay. There was no significant difference in TAP or M : Cr ratio over 18 h or between the groups. Conclusions: Our results suggest that NAC had no significant effects on the progress of the TAP and the urinary albumin excretion in our patients, which may suggest that NAC at the given dose has no clinical relevance as an early treatment in the critically ill. Author Affiliation: (1) Department of Anaesthesia and Intensive Care, Medical University of Pecs, Ifjusag u. 13, H-7643 Pecs, Hungary Fax: +36 72 315 841 email: zmolnar@apacs.pote.hu, HU (2) Department of Clinical Biochemistry, Aintree Hospitals, Liverpool, UK, GB (3) Department of Clinical Audit, Aintree Hospitals, Liverpool, UK, GB Article note: Received: 13 August 1997 Accepted: 12 December 1997

Chronic creatine depletion through long-term feeding of the creatine analog beta-guanidinopropionic (beta-GPA) acid induces reduced AMP deaminase (AMPD) levels but does not affect peak AMPD activity levels in rat fast-twitch muscles. Kinetic analyses were carried out to determine the mechanism of this maintenance of enzyme activity. Results reveal that enzymes from beta-GPA-fed rats had an additional high-affinity Michaelis-Menten constant accounting for the enhanced activity given the low concentration of AMP.

Although its efficacy in running, swimming, and nonlaboratory settings is inconclusive (1), creatine has become very popular among athletes. Some laboratory studies have shown oral creatine supplementation to be ergogenic [...]

Chronic kidney disease has been shown to adversely affect patients after total or partial nephrectomy in greater than 30% of cases. (1) Recent reports have highlighted the utility and value [...], Context.--Evaluating nontumor portions of tumor nephrectomies is useful to diagnose nonneoplastic renal disease. Objective.--To determine the medical renal disease frequency and to assess the prognostic significance of the various renal pathologic variables with long-term follow-up in tumor nephrectomy patients. Design.--We reviewed nonneoplastic kidney sections of 456 consecutive cases from 1998 to 2008. Seventy-five cases were excluded (19 tumor compression, 25 no nonneoplastic tissue, 22 embolized kidneys, 9 end stage). Special staining, immunofluorescence, and/or electron microscopy was performed where appropriate. Vascular sclerosis was scored from mild to severe; interstitial fibrosis/ tubular atrophy and global glomerulosclerosis (GS) were expressed as percentages. Follow-up, minimum 12 months, was evaluated in 156 cases. All renal pathologic variables were compared with regard to change in creatinine level from preoperative assessment to follow-up. Results.--Of 381 cases, 57 had additional medical renal disease (15%), most frequently diabetic nephropathy (28) and hypertensive nephropathy (11). Postoperative creatinine levels increased significantly in patients with severe arteriosclerosis or arteriolosclerosis, >5% GS, and >10% interstitial fibrosis/tubular atrophy. Seventy-four percent of cases with additional nonneoplastic diagnoses showed severe arteriolosclerosis. Higher corresponding GS was seen in the more affected vascular cases: mean, 5.56% GS for mild versus 23% GS for severe. Three patients progressed to renal failure 1 to 4 years after nephrectomy, 2 with hypertensive nephrosclerosis and 1 with diabetic nephropathy. Conclusions.--Medical renal disease was identified in 15% of tumor nephrectomy specimens. The degrees of vascular sclerosis, GS, and interstitial fibrosis/tubular atrophy are predictive of elevated creatinine levels in postnephrectomy patients. Prognostic implications of the nontumor pathology are important in nephrectomized patients. (Arch Pathol Lab Med. 2013;137:531-540; doi: 10.5858/arpa.2012-0070-OA)

Murphy, R., G. McConell, D. Cameron-Smith, K. Watt, L. Ackland, B. Walzel, T. Wallimann, and R. Snow. Creatine transporter protein content, localization, and gene expression in rat skeletal muscle. Am J Physiol Cell Physiol 280: C415-C422, 2001.--The present study examined the gene expression and cellular localization of the creatine transporter (CreaT) protein in rat skeletal muscle. Soleus (SOL) and red (RG) and white gastrocnemius (WG) muscles were analyzed for CreaT mRNA, CreaT protein, and total creatine (TCr) content. Cellular location of the CreaT protein was visualized with immunohistochemical analysis of muscle cross sections. TCr was higher (P [is less than or equal to] 0.05) in WG than in both RG and SOL, and was higher in RG than in SOL. Total CreaT protein content was greater (P [is less than or equal to] 0.05) in SOL and RG than in WG. Two bands (55 and 70 kDa) of the CreaT protein were found in all muscle types. Both the 55-kDa (CreaT-55) and the 70-kDa (CreaT-70) bands were present in greater (P [is less than or equal to] 0.05) amounts in SOL and RG than in WG. SOL and RG had a greater amount (P [is less than or equal to] 0.05) of CreaT-55 than CreaT-70. Immunohistochemical analysis revealed that the CreaT was mainly associated with the sarcolemmal membrane in all muscle types. CreaT mRNA expression per microgram of total RNA was similar across the three muscle types. These data indicate that rat SOL and RG have an enhanced potential to transport Cr compared with WG, despite a higher TCr in the latter. phosphocreatine; metabolism; creatine supplementation.

Brownbill, P., D. Mahendran, D. Owen, P. Swanson, K. L. Thornburg, D. M. Nelson, and C. P. Sibley. Denudations as paracellular routes for alphafetoprotein and creatinine across the human syncytiotrophoblast. Am. J. Physiol. Regulatory Integrative Comp. Physiol. 278: R677-R683, 2000.--We tested two hypotheses: 1) that fibrin-containing fibrinoid-filled denudations of the syncytiotrophoblast may provide a route for paracellular diffusion and 2) that placentas from women who had elevated maternal serum alphafetoprotein (MSAFP) in midgestation had raised permeability to AFP and greater denudation than in normal pregnancy. We measured AFP and creatinine clearance across term placental cotyledons from the above groups and used light microscope morphometric analysis to determine the volume density of fibrin-containing fibrinoid deposits. There was no significant difference between the two groups in terms of AFP and creatinine clearance or volume density of fibrin-containing fibrinoid deposits. The combined data showed a significant (P [is less than] 0.05) positive correlation between creatinine clearance, but not AFP clearance, and volume density of fibrin-containing fibrinoid. We conclude that syncytiotrophoblast denudations, with associated fibrinoid, do provide a route for diffusion of small hydrophilic solutes, but that other anatomic features of the placenta are rate limiting for transfer of AFP and similarly sized molecules. maternal serum alphafetoprotein; placenta; fibrin-containing fibrinoid

Author(s): Donald J. Weaver[sup.1] [sup.2] , Annabelle Chua[sup.1] Author Affiliations: (1) Department of Pediatrics, Levine Children's Hospital at Carolinas Medical Center, 28232, Charlotte, NC, USA (2) Division of Nephrology and [...]