Urinary calcium excretion in healthy Thai children

The objective of this study was to determine age-specific reference values for urinary calcium/creatinine ratios (UCa/Cr) of children in southern Thailand. Non-fasting urine samples were collected from a random population of 488 healthy children (282 males, 206 females) ranging in age from 17 days to 15 years. Samples were divided into six groups by age. Subjects whose calcium levels exceeded the 95th percentile within each age group were classified as having hypercalciuria. Pyuria, hematuria, proteinuria, urinary sodium, and potassium levels in children with normal UCa/Cr were compared with levels in children with high UCa/Cr. The 95th percentiles for UCa/Cr (mg/mg) by age were: <6 months, 0.75; 6 months to <12 months, 0.64; 12 months to <2 years, 0.40; 2 years to <5 years, 0.38; 5 years to <10 years, 0.29; and 10 years to <15 years, 0.26. Pyuria, hematuria, and proteinuria were no more prevalent in the 22 children with hypercalciuria than in children with normal urinary calcium levels. Urinary sodium/creatinine ratios (UNa/Cr) and urinary sodium/potassium ratios (UNa/K) were correlated with UCa/Cr (r=0.41, P<0.0001 and r=0.24, P<0.0001, respectively). Urinary potassium/creatinine ratios (UK/Cr) were not (r=0.05, P>0.1)). Children with high UCa/Cr ratios also had higher UNa/Cr and UNa/K (5.6±7.1 vs. 2.6±1.5, P<0.001 and 5.4±2.3 vs. 2.5±0.23, P<0.05, respectively) The study established reference values for random, non-fasting UCa/Cr for healthy Thai children and indicated that urinalysis is not a good indicator of hypercalciuria. Received: 30 April 1999 / Revised: 19 August 1999 / Accepted: 19 August 1999     

Urinary glycosaminoglycan excretion in healthy and stone-forming children

Both in vivo and in vitro studies suggest that macromolecules excreted in the urine, e. g. glycosaminoglycans (GAGs) may be inhibitors of kidney stone formation. We evaluated urinary GAG excretion in 22 children with calcium oxalate stones [8 with absorptive hypercalciuria, 6 with renal hypercalciuria (RH), 8 with normocalciuria], and in 20 age-matched controls. There was no significant difference between the two groups in the total urinary GAG level. In terms of the various GAG fractions, patients with RH excreted considerably less keratan sulphate and considerably more dermatan sulphate than the other patients and healthy controls. There was no difference between the two groups in condroitin sulphate, heparan sulphate and hyaluronic acid excretion. We conclude that there is no significant correlation between the formation of calcium oxalate stones and urinary GAG excretion. Received January 31, 1995; received in revised form and accepted February 6, 1996     

Urinary calcium excretion in healthy children and adolescents

Urinary calcium (Ca) excretion was determined in 1,578 24-h urine samples from 507 healthy children and adolescents (252 boys, 255 girls; 2.8–18.4 years) participating in the DONALD Study and is presented for 32 different age and sex groups. Calciuria values related to body weight (mg/kg per day) were relatively constant except for a transient decrease during puberty in all centiles, with a later onset in boys than girls. Distribution of calciuria (mg/kg per day) was best normalized by log transformation, with an almost constant standard deviation of the log-transformed values. Ca excretion was ≥4 mg/kg per day in 8.6% and ≥6 mg/kg per day in 1.5% of the urine samples. Based on Ca excretion rates of 1,080 pairs of 24-h urine samples from 364 children and adolescents, sensitivity, specificity, and the predictive value for hypercalciuria (≥4 mg/kg per day) in the next urine sample were calculated at three test levels classifying calciuria of the initial urine sample. In summary, this study presents normal values of urinary Ca excretion related to age and sex in a population of healthy German children and adolescents consuming a typical western-style diet. A high level of calciuria in a random urine sample is important in the diagnosis of hypercalciuria. Received: 25 February 1997 / Revised: 28 April 1999 / Accepted: 3 May 1999     

Urinary excretion of calcium and phosphate in preterm infants

The aims of this study were to determine reference ranges for the urinary calcium (UCa/Cr) and phosphate (UPO(4)/Cr) creatinine ratios and to study factors influencing these ratios in a representative population of preterm infants managed according to current nutritional guidelines. Spot urine samples were obtained from 186 preterm infants (gestation 24-34 weeks) for measurement of UCa/Cr and UPO(4)/Cr ratios as part of a routine metabolic bone screening program, once every 2-4 weeks from the 3rd to the 18th week of life. Data were also collected on gender, appropriate or small for gestational age (SGA), nutrition [total parenteral nutrition (TPN), preterm or term formula, and breast milk], plasma Ca, P0(4), urea, and electrolytes and on the use of drugs (frusemide, dexamethasone, and theophylline). Data from infants treated with any of these three drugs were analyzed separately and not included in establishing the reference ranges for UCa/Cr and UPO(4)/Cr. The mean gestational age of the study population was 28 weeks (range 24-34 weeks). The 95th percentile for UCa/Cr at 3 weeks of age was 3.8 mmol/mmol and decreased significantly with increasing postnatal age (P<0.001). The 95th per-centile for UPO(4)/Cr was 26.69 mmol/mmol at 3 weeks of age, but this did not change significantly with increasing postnatal age (P=0.296). On univariate analysis there was no significant association of UCa/Cr and UPO(4)/Cr with gender and type of enteral nutrition. The UCa/Cr was lower in infants who were SGA (P=0.013) and with low plasma Ca (P=0.008). Infants on TPN had significantly higher UCa/Cr (P =0.019) and lower UPO(4)/Cr ratios(P<0.001). Multivariate analysis confirmed the decrease in UCa/Cr ratio with increasing postnatal age, but the SGA effect was eliminated. The use of furosemide(P<0.001) and theophylline (P=0.003) was associated with a significant increase in the UCa/Cr ratio. The use of dexamethasone was also associated with an increase in UCa/Cr ratio, but this did not achieve statistical significance (P=0.339). The use of furosemide, theophylline,and dexamethasone had no effect on UPO(4)/Cr. We report a reference range for UCa/Cr and UPO(4)/Cr ratios and factors influencing these ratios in a representative population of preterm infants between 24 and 34 weeks gestation, managed according to current nutritional guide-lines.     

The differential diagnostic value of urinary enzyme and amino acid excretion in children with nephrotic syndrome

Urinary enzymesN-acetyl--d-glucosaminidase (NAG) and -glutamyl transpeptidase (-GT) are sensitive markers of specific renal cell damage. Excessive urinary amino acid excretion may also be an indicator of renal tubular damage. We have evaluated urinary excretion of NAG,-GT and 37 amino acids, phospholipids and dipeptides in 30 children (aged 2.3–18.1 years) with nephrotic syndrome (NS), 23 with minimal change nephrotic syndrome (MCNS), 7 with focal segmental glomerulosclerosis (FSGS) and 16 healthy age-matched controls. Nine MCNS patients were in relapse and 14 in remission. Enzyme activity is expressed as micromoles per milligram urinary creatinine. In FSGS, NAG excretion correlated with the following: blood urea nitrogen (BUN) (r=0.8), serum protein (r=0.57), serum cholesterol (r=0.85), serum albumin (r=–0.68) and proteinuria (r=0.56). In FSGS the -GT excretion was not significantly different from MCNS in remission or in relapse. In FSGS, -GT excretion correlated with the following: BUN (r=0.48), serum creatinine (r=–0.66), serum protein (r=–0.54), serum albumin (r=–0.68) and serum cholesterol (r=0.87). Compared with controls, the urinary excretion of 5 amino acids was increased in FSGS patients as a possible indicator of tubular damage. The value for 7 amino acids was reduced in MCNS patients. Urinary amino acid excretion was not different from controls for the other amino acids in either FSGS or MCNS. These data suggest that urinary enzyme excretion, particularly NAG excretion, and amino acid excretion may be useful in the diagnosis and degree of disease in these histological forms of NS in children.Crippled Childrens Foundation Research Center     

The effect of endothelin antagonists on renal ischaemia-reperfusion injury and the development of acute renal failure in the rat.

BACKGROUND:It is recognized that endothelins are released in response to hypoperfusion and anoxia of the kidney and may be responsible for the consequent deterioration in renal function. This study examined the ability of a non-selective (SB209670) and ET(A)-selective (UK-350,926) endothelin antagonist to attenuate ischaemia-induced renal failure in unilaterally nephrectomized rats. METHODS:The animals were anaesthetized, drug infusion commenced, and the renal artery occluded for 30 min. The endothelin antagonists were given for 30 min before, during, and 60 min after the ischaemic period, at 10, 30 and 100 micro g/kg/min or for 60 min after the start of reperfusion. RESULTS:On day 1, following 30 min renal artery occlusion, there was a 95% reduction in glomerular filtration rate, an 8-10-fold increase in plasma creatinine, and 10-15-fold increases in fractional excretions of sodium and potassium, which were partially resolved on day 3 and normalized on day 8. The lowest dose of SB209670 was without effect on the renal functional responses but they were blunted (all P<0.05) by the highest dose. At 30 and 100 micro g/kg/min UK-350,926, the decreases in renal function subsequent to the ischaemic challenge were attenuated. Administration of UK-350,926 at 100 micro g/kg/min for 1 h starting 60 min after the start of reperfusion, had no effect on the magnitude of the renal disturbances over the first 3 days. CONCLUSIONS:The data show that both the ET(A)/ET(B) and selective ET(A)-receptor antagonist ameliorated the ischaemia-reperfusion injury when given in the peri-ischaemic period but not when the ET(A)-receptor antagonist was given for 60 min at 100 micro g/kg/min after the ischaemic period.     

肾积水患者尿内皮素与内皮衍化舒张因子变化关系的探讨

为探讨肾积水患者尿内皮素（ET）与内皮行化舒张因子（EDRF）变化的关系，对40例单侧输尿管梗阻性肾积水患者ET与EDRF的水平进行检测，并与16例正常人作对照。发现在梗阻性肾积水患者肾盂尿中ET的水平较对照组明显升高（P＜0．01），EDRF的水平较对照组明显降低（P＜0．01），肾积水程度越重，上述变化越明显。提示在梗阻性肾积水中，梗阻肾合成的过量ET没有被定量的EDRF所拮抗，这可能是梗阻肾发生缺血性萎缩的一个原因。     

Wilson''''s病患者亲体部分肝移植和全肝移植术后血清铜蓝蛋白及尿铜水平的变化

目的　总结Wilson’s病患者亲体肝移植和全肝移植术后血清铜蓝蛋白及尿铜水平的恢复情况。方法　自 2 0 0 0年 9月至 2 0 0 3年 11月我院为 2 6例Wilson’s病患者施行了肝移植术 ,均并发终末期肝硬变 ,其中 3例发生急性肝功能衰竭。术前血清铜蓝蛋白和尿铜水平分别为 (12 4 .8± 2 2 .8)mg/L和 (15 2 4 .8± 32 8.6 ) μg/ 2 4h ,其中行活体部分肝移植 2 2例 ,全肝移植 4例 ,亲体肝移植供体术前血清铜蓝蛋白水平为 (2 30 .4± 2 9.6 )mg/L ,尿铜水平均 <5 0μg/ 2 4h。结果　所有患者手术顺利 ,全肝移植患者术后 1、3、6及 12个月血清铜蓝蛋白和尿铜水平分别为 (32 0 .2±36 .8)mg/L、(380 .4± 4 5 .6 )mg/L、(36 0 .5± 37.6 )mg/L、(35 6 .2± 2 7.6 )mg/L和 (2 4 0 .4± 2 2 .8) μg/ 2 4h、(86 .5± 10 .6 ) μg/ 2 4h、(5 4 .2± 6 .8) μg/ 2 4h及 (46 .8± 3.4 ) μg/ 2 4h ;亲体肝移植患者术后 1、3、6及 12个月血清铜蓝蛋白和尿铜水平分别为 (2 16 .8± 2 0 .4 )mg/L、(2 4 8.5± 32 .6 )mg/L、(2 85 .4± 4 4 .3)mg/L、(2 6 0 .2± 36 .6 )mg/L和(380 .8± 37.6 ) μg/ 2 4h、(15 0 .6± 2 4 .5 ) μg/ 2 4h、(75 .5± 9.6 ) μg/ 2 4h及 (6 0 .3± 5 .8) μg/ 2 4h。结论　全肝移植和亲体肝     

Urinary creatinine excretion and protein/creatinine ratios vary by body size and gender in children

Urinary protein/creatinine ratio (Up/cr) is a simple measurement for evaluation of proteinuria. However, exact effects of body size and gender on urinary excretion of creatinine and Up/cr remain unknown. We aimed to clarify their effects. Early morning urine samples were collected from 124 children with urinary tract disorders. Urinary hourly excretion of creatinine, Ucr (in milligrams per hour), urinary hourly excretion of protein per body surface area, Up (milligrams per square meter per hour), and Up/cr (milligrams per milligram) were calculated. Effects of gender, age, body height, body weight and body surface area on Ucr and Up/cr were analyzed, respectively, in a multiple linear regression model. Body surface area and gender affected Ucr (r²=0.842, P<0.0001). Ucr adjusted by body surface area increased as body surface area grew with moderate variation. Up/cr showed a close correlation with Up and was affected by body height and gender as well. The regression equation showed that Up/cr values corresponding to the normal upper limit of Up, i.e., 4 mg/m²/h, in boys and girls 170 cm tall were approximately one third of those in children 80 cm tall (0.121 vs 0.043 for boys, 0.132 vs 0.047 for girls). The present study indicates that estimation of Up/cr needs to include consideration of children’s body height and gender.     

The production and clearance of endothelin and its influence on kidney function after liver transplantation in rats

To assess the involvement of endothelin-1 (ET-1) in rat liver allograft rejection, we evaluated ET-1 expression in tissues obtained from BN (RT1ⁿ) to BN rats (group 1), and DA (RT1^a) to BN rats (group 2). The ET-1 levels in group 1, determined by radioimmunoassay, remained low in the serum, liver, and bile, but in group 2, they peaked on postoperative day (POD) 5 in the liver, kidney, bile, and urine, at 344 ±31.6pg/gwet, 306 ± 97.4pg/gwet, 1008 ± 258 pg/day, and 156 ± 45 pg/day, respectively, whereas levels in the serum peaked on POD 7 at 38.7 ± 13.1 pg/ml. In the portal vein (PV) ET-1 showed extremely high levels without statistical difference between groups 1 and 2, at 93.0 ± 15.5, and 83.0 ± 9.84 pg/ml on POD 7, respectively. However, in the suprahepatic vena cava (SHVC) and the abdominal aorta (AO), the ET-1 levels were statistically higher in group 2 compared to group 1 (P < 0.01). Immunohistochemical staining showed decreased staining of the liver and kidney in group 2 on POD 7. In conclusion, increasing levels of ET-1 were released from the liver and kidney during the early stage of rejection, resulting in the high ET-1 levels in these tissues, which were cleared promptly. However, an increased production of ET-1 was not observed in association with the release of ET-1.     

Effect of potential renal acid load of foods on urinary citrate excretion in calcium renal stone formers

The aim of this study was to investigate the influence of the potential renal acid load (PRAL) of the diet on the urinary risk factors for renal stone formation. The present series comprises 187 consecutive renal calcium stone patients (114 males, 73 females) who were studied in our stone clinic. Each patient was subjected to an investigation including a 24-h dietary record and 24-h urine sample taken over the same period. Nutrients and calories were calculated by means of food composition tables using a computerized procedure. Daily PRAL was calculated considering the mineral and protein composition of foods, the mean intestinal absorption rate for each nutrient and the metabolism of sulfur-containing amino acids. Sodium, potassium, calcium, magnesium, phosphate, oxalate, urate, citrate, and creatinine levels were measured in the urine. The mean daily PRAL was higher in male than in female patients (24.1±24.0 vs 16.1±20.1 mEq/day, P=0.000). A significantly (P=0.01) negative correlation (R=−0.18) was found between daily PRAL and daily urinary citrate, but no correlation between PRAL and urinary calcium, oxalate, and urate was shown. Daily urinary calcium (R=0.186, P=0.011) and uric acid (R=0.157, P=0.033) were significantly related to the dietary intake of protein. Daily urinary citrate was significantly related to the intakes of copper (R=0.178, P=0.015), riboflavin (R=0.20, P=0.006), piridoxine (R=0.169, P=0.021) and biotin (R=0.196, P=0.007). The regression analysis by stepwise selection confirmed the significant negative correlation between PRAL and urinary citrate (P=0.002) and the significant positive correlation between riboflavin and urinary citrate (P=0.000). Urinary citrate excretion of renal stone formers (RSFs) is highly dependant from dietary acid load. The computation of the renal acid load is advisable to investigate the role of diet in the pathogenesis of calcium stone disease and it is also a useful tool to evaluate the lithogenic potential of the diet of the individual patient.     

Urinary excretion of urodilatin in healthy children and children with renal disease

Urodilatin (URO) is a natriuretic peptide isolated from human urine which is thought to be produced by distal tubular cells. We measured urinary URO excretion in 50 healthy children and 23 children with acute (ARF), chronic renal failure (CRF), or hereditary tubular disorders, using a specific radioimmunoassay. The mean URO excreted in these four groups was 56, 45, 94, and 121 fmol/min per 1.73 m², respectively (differences between first three groups not significant). The variation in URO excretion was larger in patients with kidney disease than in controls. There were significant correlations between urinary URO and sodium excretion in controls and CRF, but not in ARF. URO excretion also correlated with urine flow rate in CRF. Although no correlation was found between URO excretion and creatinine clearance, urinary URO was increased in some patients with advanced CRF, which suggests stimulated tubular production to compensate for reduced sodium excretion. In view of the therapeutic potential of URO in renal insufficiency, further study of the renal handling of URO is warranted. Received December 4, 1996; received in revised form and accepted June 13, 1997     

Effects of the angiotensin II type 1 receptor antagonist candesartan,compared with angiotensin-converting enzyme inhibitors,on the urinary excretion of albumin and type IV collagen in patients with diabetic nephropathy

Background. We previously reported that the angiotensin II type 1 receptor antagonist candesartan was effective in reducing blood pressure and microalbuminuria in hypertensive patients with diabetic nephropathy after angiotensin-converting enzyme (ACE) inhibitors were replaced due to side effects. In the present study, the clinical effects of candesartan were investigated and compared with ACE inhibitors in patients with stage 2 or 3A diabetic nephropathy, mainly with respect to the effects on the urinary excretion of albumin and type IV collagen. Methods. Forty-nine patients (26 males/23 females) with diabetic nephropathy (stage 2 or 3A), including normotensive patients, were the study subjects. The patients were treated with either an ACE inhibitor (23 patients) or candesartan (26 patients) for 11 ± 3 months. The urinary excretion of albumin and urinary type IV collagen was measured. Results. Posttreatment blood pressure tended to decrease, but such a decrease did not reach a statistically significant level, nor did it show any intergroup difference. The urinary albumin excretion was positively correlated with pretreatment mean blood pressure and left ventricular mass index, but the urinary type IV collagen excretion did not show such correlations. The urinary albumin excretion decreased significantly after treatment to a similar extent in both groups, whereas the urinary type IV collagen excretion decreased significantly only in the candesartan group. Conclusion. It was revealed that ACE inhibitors and candesartan reduced urinary albumin excretion to a similar extent in patients with diabetic nephropathy. From the results of the present study, it is inferred that the renoprotective effect of candesartan in diabetic nephropathy may partially differ from that of ACE inhibitors.     

Urinary protein excretion and renal function in young people with diabetes mellitus.

To detect early renal involvement in young diabetic patients (IDDM), urinary protein excretion and renal function were examined in 110 patients aged 5.9-25.0 years. Clearances of inulin and PAH were determined as well as albumin (Alb), IgG, N-acetyl-beta-D-glucosaminidase (NAG) and creatinine (Cr) excretion rates (UV). The patients were grouped according to IDDM duration (2- less than 5, 5-10 and greater than 10 years) and albumin excretion rate (non-albuminuria less than 20, microalbuminuria 20-200, and albuminuria greater than 200 micrograms/min per 1.73 m2). Four patients had overt albuminuria, 17 microalbuminuria (equally distributed among the duration groups). Grouped according to albumin excretion rate, the mean GFR was increased in those without albuminuria but 'normalized' in patients with microalbuminuria/albuminuria. Grouped according to albumin excretion rate and the duration of the disease, the non-albuminuric patients with IDDM for greater than 10 years had a lower GFR than those with a shorter duration of IDDM. The patients with microalbuminuria/albuminuria and IDDM for less than 5 years had a reduced GFR. Patients with increased NAG excretion rate had lower Na excretion rate, lower fractional Na excretion and greater creatinine excretion than those with normal NAG excretion. Albumin excretion correlated with IgG excretion, but also with NAG excretion. Our results suggest that early albuminuria in IDDM is of both glomerular and tubular origin. The hyperfiltration declines with increasing albumin excretion but also with the duration of the disease.     

Urinary albumin excretion rate and its determinants after 6 years in non-insulin-dependent diabetic patients

BACKGROUND.: The present study was undertaken to clarify the progressionof urinary albumin excretion rate (UAER) in non-insulin-dependentdiabetic (NIDD) patients 6 years after diagnosis, and to elucidatethe risk factors of nephropathy. METHODS.: This is a population-based controlled (base-line) cohort study.The prospective evaluation utilized the diabetic patients asinternal controls. The setting was an urban primary health carecentre. Main outcome measures were the UAER-24 h and fractionalurinary albumin excretion rate (FAC) and their relation to meanblood pressure, haemoglobin A1c, fasting serum insulin and cholesteroland renal size. RESULTS.: UAER (mg/24 h) was increased (geometric mean, quartile 1 and3) in the diabetic patients at baseline, compared to the non-diabeticcontrol subjects; 21(10 and 33) versus 12 (8 and 15), P=0.0001(Wilcoxon's rank test). The UAER-24 h was not increased in diabeticsubjects at follow-up; 24 (7 and 49) P=0.3791 versus diabeticsubjects at baseline. Eighteen per cent of normoalbuminuric(UAER <30 mg/24 h) patients developed microalbuminuria (UAER=30–300mg/24 h) and 3% clinical nephropathy (UAER>300 mg/24 h).Of the microalbuminuric subjects 19% progressed to clinicalnephropathy, 46% remained microalbuminuric and 35% remittedto normoalbuminuria. Serum insulin concentration, after assessmentof confounding factors, measured at the baseline predicted theUAER for all diabetic subjects at follow-up in multiple linearregression analysis in an independent and significant way (P=0.01).Serum insulin concentration (P=0.034) and diuretic therapy (P=0.050)at baseline independently predicted the outcome of the categoricalvariable progressor/nonprogressor (n=22/86) based on the UAER-24h at baseline and at follow-up. CONCLUSIONS.: Progression of the UAER during the first 6 years is found amongapproximately every fifth NIDD subject who develops either microalbuminuria(from normoalbuminuria) or clinical nephropathy (from microalbuminuria).The role of serum insulin (insulin resistance) or some factorassociated with it, is suggestive in the genesis of kidney disease.     

Urinary excretion of phthalates and paraben after repeated whole-body topical application in humans

Diethyl phthalate (DEP), dibutyl phthalate (DBP) and butyl paraben (BP) are man-made chemicals used in personal care products, such as lotions and creams. Exposure to these chemicals causes a variety of adverse reproductive outcomes in animal studies. Humans can be exposed to these chemicals through dermal absorption, but there are no published data on absorption, metabolism, and excretion after dermal application. This study investigates urinary concentrations of BP and metabolites of DEP and DBP after topical application. In a 2-week single-blinded study, 26 healthy Caucasian male subjects were given a whole body topical application of basic cream 2 mg/cm(2) (control week) and then a cream containing 2% (w/w) of DEP, DBP and BP each (treatment week) daily. Twenty-four-hour urine samples were collected. Urinary total, and unconjugated BP, monoethyl phthalate (MEP) and monobutyl phthalate (MBP) metabolites were analysed by Liquid Chromatography-Tandem Mass Spectroscopy (LC-MS/MS). All 26 subjects showed increased excretion of MEP, MBP and BP following topical application. Total MEP, MBP and BP (mean +/- SEM) excreted in urine in the treatment week were, respectively, 41 +/- 1.9, 11.8 +/- 0.6 and 2.6 +/- 0.1 mg/24 h. On average 5.79, 1.82 and 0.32%, respectively, of the applied DEP, DBP and BP could be recovered in urine as MEP, MBP and BP. The concentration of the compounds peaked in urine 8-12 h after application. The fractions of unconjugated MEP, MBP, and BP were 78, 8.0 and 2.1%, respectively. Absorption of DEP, DBP and BP through skin could potentially contribute to adverse health effects. The three chemicals are systemically absorbed, metabolized and excreted in urine following application on the skin in a cream preparation. More DEP than DBP was absorbed, presumably because of a faster absorption rate for DEP.     

Body Mass Index and Urinary Symptoms in Women

The aim of this study was to assess a possible correlation between obesity and lower urinary tract symptoms in a selected population of women. All the subjects referred for lower urinary tract complaints over a 2-year period received a questionnaire and a frequency/volume chart. The patient population was divided into normal or low weight (BMI ≤29) and high weight and obese (BMI ≥30). The main outcome measures were lower urinary tract symptoms (infections, frequency, urgency, voiding difficulty, dysuria, nocturia and incontinence). The statistical analysis was performed using the Mann–Whitney U-test, χ² test and odds ratios; 694 women received the questionnaire and 553 were evaluated (79.7% response). Overall, 229 (42.4%) were of low or normal BMI; 311 (57.5%) had a high or obese BMI. After adjusting for prior bladder surgery, any surgery, history of medical problems and physical inactivity, only the association between BMI and incontinence remained statistically significant (adjusted OR 1.95; 95% CI 1.18–3.19).     

Urinary N-acetyl-beta-glucosaminidase excretion is a marker of tubular cell dysfunction and a predictor of outcome in primary glomerulonephritis.

BACKGROUND: The urinary excretion of N-acetyl-beta-glucosamynidase (NAG) is increased in subjects exposed to substances toxic for renal tubular cells. In experimental and human glomerular diseases, its increased excretion is probably due to the dysfunction of tubular epithelial cells induced by increased traffic of proteins in the tubular lumen. The first aim of this study was to evaluate whether NAG excretion is correlated not only with the amount of proteinuria but also with some proteinuric components which reflect both glomerular capillary wall damage (IgG) and an impairment of tubular reabsorption of microproteins (alpha(1) microglobulin). The second aim was to assess whether NAG excretion has a predictive value on functional outcome and response to therapy. METHODS: In 136 patients with primary glomerulonephritis [74 with idiopathic membranous nephropathy (IMN), 44 with primary focal segmental glomerulosclerosis (FSGS) and 18 with minimal change disease (MCD)] urinary NAG excretion was measured by a colorimetric method and expressed in units per gram of urinary creatinine. RESULTS: Using univariate linear regression analysis NAG excretion in all 136 patients was significantly dependent on IgG excretion, 24-h proteinuria, fractional excretion of alpha(1) microglobulin (FE alpha(1)m) and diagnosis. Using multiple linear regression analysis, NAG excretion was significantly dependent only on IgG excretion and 24-h proteinuria. Limiting the analysis to 67 patients with nephrotic syndrome (NS) and baseline normal renal function, by multiple linear regression, NAG excretion was significantly dependent on IgG excretion (P=0.0004), 24-h proteinuria (P=0.0067) and FE alpha(1)-m (P=0.0032) (R(2)=0.63). In 66 patients with NS and normal baseline renal function (MCD 10 patients; FSGS 20 patients; IMN 36 patients), according to values below or above defined cut-offs (IMN, 18 U/g urinary Cr; FSGS and MCD, 24 U/g urinary Cr), NAG excretion predicted remission in 86 vs 27% of IMN patients (P=0.0002) and 77 vs 14% of FSGS patients (P=0.005). Progression to chronic renal failure (CRF) was 0 vs 47% in IMN patients (P=0.001) and 8 vs 57% in FSGS patients (P=0.03). Using Cox model, in IMN patients only NAG excretion (P=0.01, RR 5.8), but not 24-h proteinuria, predicted progression to CRF. All MCD patients had NAG excretion values below the chosen cut-off, and 90% of them developed remission. Response to immunosuppressive therapy was significantly different in patients with NAG excretion values below or above the cut-offs. CONCLUSION: Urinary NAG excretion can be considered as a reliable marker of the tubulo-toxicity of proteinuria in the early stage of IMN, FSGS and MCD; the excretion values show a significant relationship with 24-h proteinuria, IgG excretion and FE alpha(1)m. Its determination may be a non-invasive, useful test for the early identification of patients who will subsequently develop CRF or clinical remission and responsiveness to therapy.