PURPOSE: The prevalence of obesity in children and adolescents has been rising rapidly in Korea because of changes of diet and lifestyle. As with adults, obesity in children and adolescents can cause diabetes mellitus, hyperlipidemia, cardiovascular diseases and renal diseases. The aim of the present study is to examine the relation of obesity, glomerular filtration rate (GFR) and serum cystatin C concentration in children and adolescents. METHODS: Data of 115 children and adolescents aged between 6 years and 20 years without clinical evidence of renal diseases were included in the study. From May 2004 to December 2004, blood samples were collected from children and adolescents who were seen at the Department of Pediatrics at Chungang University Yongsan Hospital. Obesity degrees and body mass indices (BMI) were measured, and GFRs were estimated from Schwartz's formula. Serum cystatin C was measured by particle enhanced nephelometric immunoassay using Behring Nephelometer II. RESULTS: GFRs were significantly different between the obese group (BMI > 95 percentile, 145.79+/-23.10 mL/min) and the non-obese group (BMI < 95 percentile, 134.61+/-26.19 mL/min) divided by BMI (P=0.031). GFRs were not significantly different between the obese group (obesity degree > 120 percent, 144.29+/-23.08 mL/min) and the non-obese group (obesity degree < 120 percent, 134.54+/-26.57 mL/ min) divided by obesity degree (P=0.051), but were significantly different between severe obese group (obesity degree > 150 percent, 155.55+/-20.40 mL/min) and the non-obese group (P=0.004). GFRs were correlated positively with BMI (r2=0.037, P=0.039), but were not correlated significantly with obesity degree (r2=0.030, P=0.066). Serum cystatin C concentrations were not significantly different between the obese group and the non-obese group, divided by BMI as well as by obesity degree (P> 0.05). CONCLUSION: Obesity may lead to an alteration of renal hemodynamics such as hyperfiltration, appropriate control and management for obesity is necessary.
Child ; Adolescent ; Adult ; Male ; Female ; Humans

PURPOSE: Glomerular filtration rate (GFR) is a fundamental parameter in assessing renal function and predicting the progression of chronic renal disease. Because the use of serum creatinine has several disadvantages, many studies have investigated the use of cystatin C for estimating GFR. We compared creatinine clearance and GFR with formulas using serum creatinine and cystatin C. METHODS: We retrospectively analyzed 211 patients with various renal diseases and classified them into two groups according to creatinine clearance (Group 1: CrCl >90 mL/min/1.73m2, Group 2: CrCl <90 mL/min/1.73m2). We measured serum creatinine, cystatin C, and creatinine clearance. We calculated GFR using the Schwartz, Counahan, Filler and Lepage, Bokencamp et al, and Grubb et al formulas. RESULTS: GFR determined by the Schwartz formula had the highest correlation to creatinine clearance (r=0.415, P=0.00). GFR determined by various formulas using cystatin C had lower correlation to creatinine clearance (r=0.187, r=0.187, r=0.291). The Schwartz and Counahan formulas showed greater diagnostic accuracy in detecting decreased GFR than cystatin C in group 2 (areas under the curve: Schwartz, 0.596; Counahan, 0.572; Filler, 0.512; Bokencamp, 0.508; and Grubb, 0.514). CONCLUSION: GFR determined by the Schwartz and Counahan formulas using serum creatinine showed higher correlation coefficient than that determined by formulas using cystatin C. The formulas using cystatin C were not superior to those using serum creatinine in detecting decreased GFR. Cystatin C measurement was not satisfactory for assessing GFR in patients whose renal function was not severely decreased.
Child ; Creatinine ; Cystatin C ; Glomerular Filtration Rate ; Humans ; Renal Insufficiency, Chronic ; Retrospective Studies

PURPOSE: Glomerular filtration rate (GFR) is a fundamental parameter in assessing renal function and predicting the progression of chronic renal disease. Because the use of serum creatinine has several disadvantages, many studies have investigated the use of cystatin C for estimating GFR. We compared creatinine clearance and GFR with formulas using serum creatinine and cystatin C. METHODS: We retrospectively analyzed 211 patients with various renal diseases and classified them into two groups according to creatinine clearance (Group 1: CrCl >90 mL/min/1.73m2, Group 2: CrCl <90 mL/min/1.73m2). We measured serum creatinine, cystatin C, and creatinine clearance. We calculated GFR using the Schwartz, Counahan, Filler and Lepage, Bokencamp et al, and Grubb et al formulas. RESULTS: GFR determined by the Schwartz formula had the highest correlation to creatinine clearance (r=0.415, P=0.00). GFR determined by various formulas using cystatin C had lower correlation to creatinine clearance (r=0.187, r=0.187, r=0.291). The Schwartz and Counahan formulas showed greater diagnostic accuracy in detecting decreased GFR than cystatin C in group 2 (areas under the curve: Schwartz, 0.596; Counahan, 0.572; Filler, 0.512; Bokencamp, 0.508; and Grubb, 0.514). CONCLUSION: GFR determined by the Schwartz and Counahan formulas using serum creatinine showed higher correlation coefficient than that determined by formulas using cystatin C. The formulas using cystatin C were not superior to those using serum creatinine in detecting decreased GFR. Cystatin C measurement was not satisfactory for assessing GFR in patients whose renal function was not severely decreased.
Child ; Creatinine ; Cystatin C ; Glomerular Filtration Rate ; Humans ; Renal Insufficiency, Chronic ; Retrospective Studies

PURPOSE: Cystatin C has been proposed for the assessment of glomerular filtration rate, being more accurate than creatinine determination. We measured serum cystatin C concentrations in the pediatric population, and analysed the correlation between cystatin C and glomerular filtration rate. METHODS: Cystatin C and creatinine were measured by the particle enhanced nephelometric immunoassay and Jaff'e method, respectively, in 276 children and adolescents without evidence of kidney disease. The glomerular filtration rate was estimated by Schwartz's formula. RESULTS: The mean serum cystatin C concentration was significantly higher in infants under the age of 12 months than in older population. There was a negative correlation between cystatin C and age under 12 months, but not a significant change of cystatin C with age in children older than 12 months For children older than 12 months, the reference range of cystatin C was 0.46-1.05 mg/L. On the other hand, there was a positive correlation between creatinine and age in the whole population. We also observed a positive correlation between estimated glomerular filtration rate and 1/ cystatin C. CONCLUSION: The measurement of cystatin C is more practical than creatinine for estimating glomerular filtration rate in the pediatric population.
Adolescent* ; Child* ; Creatinine ; Cystatin C* ; Glomerular Filtration Rate* ; Hand ; Humans ; Immunoassay ; Infant ; Kidney Diseases ; Reference Values

Concerning our medical history, the importance of medical terms has been neglected for a long time. In addition, medical terminologies are unaccustomed to the patients including the public. The separation of communications between the public and medical participants has been enlarged more and more. The importance of terms which can be easily recognized, comfortable to the ear, and familiar to the public have arose to the point when the Korean Medical Association established a medical terms enactment in 1976 and made the first series of medical terms. These efforts have been continued to the second in 1983, the third in 1992 and the fourth series in 2001. Throughout this revision, we wish new terms of fourth series may contribute to the better communication between the doctors and patients. It will be able to function as a better and enhanced tool to the public who require medical information. The terms of present lecture are based on the fourth series of medical terms. Because it is irrational to use all the reformed terms, in this lecture we have used the most commonly used clinical terms as a hope for the pediatricians to give better medical treatment.
Ear ; Hope ; Humans

PURPOSE: Since children under two years with suspected urinary tract infections (UTIs) cannot control urination, urine cultures in such children are usually performed via urine bags. This method is noninvasive but has a high contamination rate. We studied the contamination rate of bag urine culture in diagnosing UTIs in infants under two years and the factors responsible for contamination. METHODS: We examined patients under 2 years in whom urine culture through the urine bag method yielded over 105 colonies of a single pathogen. We defined UTIs by referring to the guidelines of The Korean Society of Pediatric Nephrology, 2005. We examined the factors responsible for contamination according to sex, duration of urine collection, and whether diarrhea took place with contamination rate. RESULTS: We examined 717 patients (412 males and 305 females). The contamination rate of one bag urine culture was 37.9%. Gender was not related to the contamination rate (P>0.05). Duration of urine collection showed an association with the contamination rate. The longer the duration of collecting urine, the higher was the contamination rate. Duration of urine collection was divided into three groups: first group, <2 hours; second group, 2-4 hours; and third group, > or =4 hours. The contamination rates were 30.0%, 42.2%, and 43.7% for the first, second, and third groups, respectively, with statistical significance (P=0 .001). Diarrhea at admission had no impact on the contamination rate (P>0.05). CONCLUSION: The contamination rate of urine culture in the examined patients was 37.9%. Gender and diarrhea symptoms were not responsible for contamination. In infants with a suspected UTIs, urine should be collected within 2 hours through the urine bag method. If urine collection takes over 2 hours, the urine bag should be resterilized and reattached to the patient.
Child ; Diarrhea ; Humans ; Hypogonadism ; Infant ; Male ; Mitochondrial Diseases ; Nephrology ; Ophthalmoplegia ; Urinary Tract Infections ; Urination ; Urine Specimen Collection

PURPOSE: Lipoprotein(a) is a genetically determined risk factor for atherosclerotic vascular disease and is elevated in patients with renal disease. Especially the patients with nephrotic syndrome exhibit excessively high Lp(a) plasma concentrations. Also the patients with end- stage renal disease have elevated Lp(a) levels. But the mechanism underlying this elevation is unclear. Thus, in this study, by measuring the level of serum Lp(a) in common renal diseases in children, we hoped to see whether there would be a change in Lp(a) in renal diseases other than nephrotic syndrome. Then, we figured out its implications, and looked for the factors that affect the Lp(a) concentrations. METHODS: A total of 75 patients(34 patients with hematuria of unknown etiology, 10 with hematuria and hypercalciuria, 8 with IgA nephropathy, 8 with poststreptococcal glomerulonephritis, 3 with Henoch-Schonlein nephritis, 7 with urinary tract infection, and 5 with orthostatic proteinuria) were studied. The control group included 20 patients without renal and liver disease. Serum Lp(a), total protein, and albumin levels, 24-hour urine protein and calcium excretions, creatinine clearance and the number of RBCs and WBCs in the urinary sediment were evaluated. Data analysis was performed using the Student t-test and a P-value less than 0.05 was considered to be statistically significant. RESULTS: Lp(a) was not correlated with 24-hour urine calcium and creatinine. Lp(a) level had a positive correlation with proteinuria and negative correlation with serum albumin and serum protein. Among the common renal diseases in children, Lp(a) was elevated only in orthostatic proteinuria(P<0.05). CONCLUSION: Lp(a) is correlated with proteinuria, serum protein, and serum albumin, but not with any kind of specific renal disease. Afterward, Lp(a) needs to be assessed in patients with orthostatic proteinuria and its possible role as a prognostic factor could be confirmed.
Calcium ; Child* ; Creatinine ; Glomerulonephritis ; Glomerulonephritis, IGA ; Hematuria ; Hope ; Humans ; Hypercalciuria ; Lipoprotein(a)* ; Liver Diseases ; Nephritis ; Nephrotic Syndrome ; Plasma ; Proteinuria ; Risk Factors ; Serum Albumin ; Statistics as Topic ; Urinary Tract Infections ; Vascular Diseases

PURPOSE: Lipoprotein(a) is a genetically determined risk factor for atherosclerotic vascular disease and is elevated in patients with renal disease. Especially the patients with nephrotic syndrome exhibit excessively high Lp(a) plasma concentrations. Also the patients with end- stage renal disease have elevated Lp(a) levels. But the mechanism underlying this elevation is unclear. Thus, in this study, by measuring the level of serum Lp(a) in common renal diseases in children, we hoped to see whether there would be a change in Lp(a) in renal diseases other than nephrotic syndrome. Then, we figured out its implications, and looked for the factors that affect the Lp(a) concentrations. METHODS: A total of 75 patients(34 patients with hematuria of unknown etiology, 10 with hematuria and hypercalciuria, 8 with IgA nephropathy, 8 with poststreptococcal glomerulonephritis, 3 with Henoch-Schonlein nephritis, 7 with urinary tract infection, and 5 with orthostatic proteinuria) were studied. The control group included 20 patients without renal and liver disease. Serum Lp(a), total protein, and albumin levels, 24-hour urine protein and calcium excretions, creatinine clearance and the number of RBCs and WBCs in the urinary sediment were evaluated. Data analysis was performed using the Student t-test and a P-value less than 0.05 was considered to be statistically significant. RESULTS: Lp(a) was not correlated with 24-hour urine calcium and creatinine. Lp(a) level had a positive correlation with proteinuria and negative correlation with serum albumin and serum protein. Among the common renal diseases in children, Lp(a) was elevated only in orthostatic proteinuria(P<0.05). CONCLUSION: Lp(a) is correlated with proteinuria, serum protein, and serum albumin, but not with any kind of specific renal disease. Afterward, Lp(a) needs to be assessed in patients with orthostatic proteinuria and its possible role as a prognostic factor could be confirmed.
Calcium ; Child* ; Creatinine ; Glomerulonephritis ; Glomerulonephritis, IGA ; Hematuria ; Hope ; Humans ; Hypercalciuria ; Lipoprotein(a)* ; Liver Diseases ; Nephritis ; Nephrotic Syndrome ; Plasma ; Proteinuria ; Risk Factors ; Serum Albumin ; Statistics as Topic ; Urinary Tract Infections ; Vascular Diseases

Hypokalemia and hyperkalemia are the most commonly encountered electrolyte abnormalities in hospitalized patients. Because untreated hypokalemia or hyperkalemia is associated with high morbidity and mortality, it is important to recognize and treat them immediately. Hypokalemia and hyperkalemia can result from disruptions in transcellular homeostasis or in the renal regulation of K+ excretion. Although the recognition is simple, appropriate management requires an understanding of normal K+ homeostasis and pathophysiology. In this article, normal K+ homeostasis, pathophysiology, diagnosis and management of hypokalemia and hypokalemia are discussed.
Diagnosis ; Homeostasis ; Humans ; Hyperkalemia* ; Hypokalemia* ; Mortality ; Potassium

PURPOSE: Urinary excretion of N acetyl-beta-D glucosaminidase (NAG) and beta2-microglobulin (beta2-M) was increased in the presence of proximal tubular damage. Based on these urinary materials, we investigated the ability of expecting renal function in chronic glomerular diseases. In this study, we evaluated the relationship between glomerular filtration rate (GFR) urinary NAG, and urinary beta2-M. METHODS: We evaluated 52 children with chronic kidney disease at the Chung-Ang University Hospital between January 2003 and August 2009. We investigated the 24-hour urinalysis and hematologic values in all 52 patients. Serum creatinine, creatinine clearance (Ccr), serum cystatin C, urinary beta2-M and urinary NAG were measured. RESULTS: Out of 52 patients, there were 13 children with minimal change in disease, 3 children with focal segmental glomerulosclerosis, 17 children with immunoglobulin A nephropathy, 15 children with Henoch-Schonlein purpua nephritis, 3 children with poststreptococcal glomerulonephritis, and 1 child with thin glomerular basement membrane disease. In these patients, there were significant correlation between the Ccr and urinary NAG (r=-0.817; P<0.01), and between the GFR (as determined by Schwartz method) and urinary NAG (r=-0.821; P<0.01). In addition, there was a significant correlation between the GFR (as determined by Bokencamp method) and urinary NAG (r=-0.858; P<0.01). CONCLUSION: In our study, there was a significant correlation between the GFR and urinary NAG, but there was no correlation between the GFR and urinary beta2-M, suggesting that the GFR can be predicted by urinary NAG in patients with chronic glomerular disease.
Child ; Creatinine ; Cystatin C ; Glomerular Basement Membrane ; Glomerular Filtration Rate ; Glomerulonephritis ; Glomerulonephritis, IGA ; Glomerulosclerosis, Focal Segmental ; Hexosaminidases ; Humans ; Nephritis ; Proteinuria ; Renal Insufficiency, Chronic ; Urinalysis