Contrast-Induced Nephropathy in Patients Undergoing Intravenous Contrast-Enhanced Computed Tomography in Korea: A Multi-Institutional Study in 101487 Patients

OBJECTIVE: To evaluate the prevalence of known risk factors for contrast-induced nephropathy (CIN) and their association with the actual occurrence of CIN in patients undergoing intravenous contrast-enhanced computed tomography (CECT) in Korea. MATERIALS AND METHODS: Patients who underwent CECT in 2008 were identified in the electronic medical records of 16 tertiary hospitals of Korea. Data on demographics, comorbidities, prescriptions and laboratory test results of patients were collected following a standard data extraction protocol. The baseline renal function was assessed using the estimated glomerular filtration rate (eGFR). We identified the prevalence of risk factors along the eGFR strata and evaluated their influence on the incidence of CIN, defined as a 0.5 mg/dL or 25% increase in serum creatinine after CECT. RESULTS: Of 432425 CECT examinations in 272136 patients, 140838 examinations in 101487 patients met the eligibility criteria for analysis. The mean age of the participants was 57.9 +/- 15.5 years; 25.1% of the patients were older than 70 years. The prevalence of diabetes mellitus was 11.9%, of hypertension 13.7%, of gout 0.55% and of heart failure was 1.7%. Preventive measures were used in 40238 CECT examinations (28.6%). The prevalence of risk factors and use of preventive measures increased as the renal function became worse. A CIN was occurred after 3103 (2.2%) CECT examinations, revealing a significant association with decreased eGFR, diabetes mellitus, and congestive heart failure after adjustment. CONCLUSION: Risk factors for CIN are prevalent among the patients undergoing CECT. Preventive measures were seemingly underutilized and a system is needed to improve preventive care.

Serum Osteoprotegerin Levels and the Extent of Aortic Calcification in Hemodialysis Patients / 대한신장학회잡지

BACKGOUND: Vascular calcification is highly correlated with cardiovascular disease mortality, especially in patients with end-stage renal disease (ESRD). Recent experimental research has implicated osteoprotegerin (OPG) in medial arterial calcification. The present study aims to examine whether serum OPG level is associated with the extent of aortic calcification in hemodialysis patients. METHODS: We studied 57 ESRD patients (59.5+/-14.1 years) on maintenance hemodialysis. Serum OPG level was measured by enzyme-linked immunosorbent assay. Abdominal aortic calcific deposits index (AAC index) was analysed with lateral lumbar radiograms. Patients were classified into tertile groups according to their AAC index: group I (0, n= 18), group II (1-4, n=18) and group III (5-18, n=21). Brachial ankle pulse wave velocity (baPWV) was also measured. RESULTS: Serum OPG level was greater in patients with higher AAC index than in those with lower AAC index but it was not statistically significant (group I: 409.8+/-343.5 pg/mL, group II: 575.9+/-723.3 pg/mL and group III: 660.8+/-593.5 pg/mL, p=0.399). There was a trend that serum OPG level was positively associated with AAC index, but it was not statistically significant (r=0.089, p=0.511). Serum OPG level showed positive correlation with age and pulse pressure. AAC index positively related with age and baPWV. CONCLUSION: Serum OPG levels seems to be positively related to AAC index by lateral lumbar radiograms, but it was not statistically significant. We suggest more extended studies to determine that serum OPG is helpful clinical marker for the extent of vascular calcification in maintenance hemodialysis patients.

Hypertension and Renal Function in Autosomal Dominant Polycystic Kidney Disease according to Renal Structural Indices / 대한신장학회잡지

Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary disorder, and its major morbidities are hypertension and renal failure. It is a characteristic feature of ADPKD that renal cysts increase in size and number with age continuously. Hypertension and renal failure in ADPKD result from compression of residual normal renal parenchyma by expanding cysts, since renal tissue is trapped within the poorly distensible renal capsule. Renal structural deformities in ADPKD occur prior to hypertension and renal failure. The present study was undertaken to explore the potential role of renal cyst enlargement in initiating hypertension and renal failure in ADPKD. We therefore measured renal structural indices by computed tomography(CT) to examine the relation between clinical progression and renal structural deformities. Sixty-seven adult subjects(45+/-12 years, male-female ratio 42 : 25) with ADPKD were studied at our PKD clinic from 1997 to 2000, and a complete abdominal CT was performed on all subjects. One radiologist measured the renal structural indices which were renal length, volume, RSI(anatomical renal severity index) and maximal cyst size. The renal structural indices were significantly greater in hypertensive group compared to the normotensive group (hypertensive 833+/-585 vs. normotensive 360+/-154mL/1.73m2, p<0.01). The renal structural indices were significantly greater in renal failure group compared to the normal renal function group(renal failure 1,171+/-700 vs. normal 499+/-335mL/1.73m2, p<0.01). The renal function in ADPKD correlated with the renal structural indices. We concluded that the clinical progression in ADPKD correlates with the renal structural indices well. These structural indices provide considerable information about the progression of ADPKD.

The Value of Intrarenal Resistive Index in Patients with Liver Cirrhosis

PURPOSE: To determine whether the value of the intrarenal resistive index (RI) can be used to identify early kidney vasoconstriciton in patients with nonazotemic liver cirrhosis MATERIALS AND METHODS: The intrarneal resistive index(RI), kidney and liver function and plasma renin activity were measured in 12 healthy control subjects, 13 cirrhotic patients without ascites and 29 cirrhotic patients with ascites. To evaluate the development of hepatorenal syndrome, patients were followed up for six months. RESULTS: RI was significantly higher in patients with cirrhosis (0.68+/-0.06) than in healthy subjects(0.59+/-0.04). In 42 cirrhotic patients, it was significantly higher in those with ascites (0.69+/-0.05) than in those without ascites(0.64+/-0.05) and correlated with creatinine clearance. Plasma renin activity was significantly highter in cirrhotic patients with ascites than in those without ascites and healthy subjects(p<0.05). During the six-month follow-up period, kidney dysfunction developed in 16% (7/42) of cirrhotic patiens, and in 37% (6/16) of those with an elevated RI. In contrast, only 4% (1/26) of patients with a normal RI has kidney dysfunction. CONCLUSION: The measurement of intrarenal resitive index (RI) using duplex Doppler ultrasound is a simple, noninvasive method of detecting even subtle derangements of renal hemodynamics in liver cirrhosis patients; the procedure can be used to identify those who are at higher risk of overt renal failure and to help decide whether a therapeutic approach involving paracentesis, diuretics, or nephrotoxic agents is most appropriate.