Morning Void Urine Research Articles

Abstract B90: Variation in circadian rhythm genes and risk of prostate cancer in the AGES-Reykjavik cohort

Abstract Background: Disruption of sleep duration or circadian rhythms has been associated with an increased risk of prostate cancer. Studies have suggested that circadian genes may be involved in regulating cancer-related pathways, such as cell proliferation, DNA damage response and apoptosis. As such, we hypothesized that genetic susceptibility to prostate cancer may be in part due to common variation in the core circadian rhythm genes. We assessed the association of genetic variation in core circadian rhythm genes with risk of prostate cancer and with urinary levels of melatonin among men in the prospective Age, Gene/Environment Susceptibility (AGES)-Reykjavik study. Methods: The study population was 1,352 men in the AGES-Reykjavik cohort with data from a previous genome wide association study. We examined 96 single-nucleotide polymorphisms (SNPs) across twelve genes chosen to represent common variation in genes that control the circadian rhythm (CLOCK, neuronal PAS domain protein 2 (NPAS2), aryl hydrocarbon receptor nuclear translocator-like (ARNTL), cryptochrome 1(CRY1), cryptochrome 2 (CRY2), period 1 (PER1), period 2 (PER2), period 3 (PER3), casein kinase 1-epsilon (CSNK1E)), two melatonin receptor genes (MTNR1A and MTNR1B), and the Timeless (TIM) gene. Melatonin levels were determined from first morning void urine samples using an ELISA assay. Prostate cancer (N = 138) was identified from hospital records using ICD codes; death from prostate cancer (N = 24) was determined from nationwide death records. We used unconditional logistic regression to evaluate the association between each SNP and overall and lethal prostate cancer. Linear regression was used to assess the association between each SNP and log-transformed melatonin levels. Finally, to test whether multimarker SNP-sets in the pathway were associated with prostate cancer or melatonin levels, we used a kernel machine test. Results: None of the 96 SNPs evaluated were significantly associated with prostate cancer overall. The variant allele in two SNPs in CRY1 (rs7297614 and rs1921126) and one in PER1 (rs2289591) were nominally (p-value <0.05 without adjusting for multiple testing) associated with an elevated risk of lethal prostate cancer, while SNPs in NPAS2 (rs3754674), ARNTL (rs969485) and PER2 (rs10462023) were nominally associated with a reduced risk of lethal disease. Among men without cancer, 4 SNPs in TIM and 6 in NPAS2 were nominally associated with lower levels of urinary melatonin; 2 SNPs in PER3 and 1 in CSNK1E were associated with higher levels of urinary melatonin. Pathway analyses showed that variability across the individual genes CRY1 and PER2 were nominally associated with lethal prostate cancer (p-value 0.01 and 0.05, respectively). For melatonin levels, the set of SNPs across all 12 genes and TIM was nominally associated with urinary melatonin levels (p-value 0.05 and 0.02, respectively). Conclusion: Variation in circadian genes, such as PER1, CRY1, and CRY2, has been previously associated with increased prostate cancer risk; variation in NPAS2 has been associated with reduced prostate cancer risk. Similar to previously reported literature, we observed several suggestive associations between variation in genes that regulate the circadian rhythm and lethal prostate cancer risk as well as urinary melatonin levels. Our findings provide further support for a role of circadian disruption in prostate cancer progression. Citation Format: Sarah Coseo Markt, Unnur A. Valdimarsdottir, Lara G. Sigurdardottir, Irene M. Shui, Jennifer R. Rider, Julie L. Kasperzyk, Steven W. Lockley, Charles A. Czeisler, Meir J. Stampfer, Thor Aspelund, Albert Vernon Smith, Vilmundur Gudnason, Lorelei A. Mucci. Variation in circadian rhythm genes and risk of prostate cancer in the AGES-Reykjavik cohort. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr B90.

Objective non-intrusive markers of sperm production and sexual activity

Objective studies of men's reproductive function are hindered by their reliance on: (i) self-reporting to quantify sexual activity and (ii) masturbation to quantify sperm output rendering both types of estimate vulnerable to unverifiable subjective factors. We therefore examined whether detection of spermatozoa and measurement of prostate-specific antigen (PSA) in urine could provide objective semiquantitative estimates of sperm output and recent ejaculation, respectively, using widely available laboratory techniques. Of 11 healthy volunteers who provided urine samples before and at intervals for 5 days after ejaculation, sperm was present in 2/11 men before, and in all 11/11 samples immediately after ejaculation, but by the second and subsequent void, spermatozoa were present in ∼10%. PSA was detectable at high levels in all urine samples, peaking at the first post-ejaculatory sample but returning to baseline levels by the second post-ejaculatory void. We conclude that urinary spermatozoa and PSA are objective biomarkers for sperm production and sexual activity, but only for a short-time window until the first post-ejaculatory urine void. Hence, for a single urine specimen, the presence of spermatozoa and PSA are valid biomarkers, reflecting sperm production and recent ejaculation only until the next micturition, so their measurement should be restricted to the first morning urine void.

Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

The Binational Arsenic Exposure Survey (BAsES) was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic) and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L) whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001), urinary inorganic arsenic concentration (p < 0.001), and urinary sum of species (p < 0.001). Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

Polycyclic aromatic hydrocarbon (1-OHPG and 2-naphthol) and oxidative stress (malondialdehyde) biomarkers in urine among Korean adults and children

Using the urinary biomarkers 1-hydroxypyrene-glucuronide (1-OHPG), 2-naphthol, and malondialdehyde (MDA), we evaluated seasonal and regional variations in polycyclic aromatic hydrocarbon (PAH) exposure and oxidative stress among Korean adults and children. In total, 322 children (175 male and 147 female) and 332 adults (47 male and 285 female) were recruited in two regions of Korea, one representing a metropolitan area (Seoul/Incheon) and the other an industrial (Pohang) area, from winter 2002 to spring 2003. The subjects voluntarily gathered their first morning urine void, which was immediately transported to our laboratory and stored at -20 °C. Urinary 1-OHPG was measured by synchronous fluorescence spectroscopy, 2-naphthol by HPLC, and urinary MDA by HPLC with a UV detector. The median urinary 1-OHPG concentration tended to be higher in the industrial region than in the metropolitan region (0.92 vs. 0.77 ng/mL; p=0.03), and higher in winter than in spring (0.95 vs. 0.73 ng/mL; p<0.001). The median 2-naphthol concentration was also higher in the industrial region than in the metropolitan region (21.0 vs. 12.3 ng/mL; p<0.0001), but was higher in spring than in winter (19.7 vs. 10.3 ng/mL; p<0.0001). The median MDA concentration was significantly higher in winter than in spring (2.19 vs. 1.03 μmol/L; p<0.0001), whereas regional variation in MDA was observed only in female adults (p=0.02). In winter, the level of 1-OHPG was higher in children exposed to environmental tobacco smoke than in unexposed children (0.94 vs. 0.86 ng/mL; p=0.02). Our results indicate that both region and season can significantly influence the levels of PAH exposure and oxidative stress biomarkers.

Integrating metabolomic signatures and psychosocial parameters in responsivity to an immersion treatment model for adolescent obesity

With childhood obesity tripling in the past two decades alone, developing effective treatment to promote long-term weight loss and maintenance is critical. Unfortunately, while many children respond favorably to behavioral treatments, failure to lose and maintain weight loss is common. There is a critical need to determine non-invasive markers that can serve to predict an individual’s likelihood of having a positive response to treatment, and to monitor the treatment progress for early identification of those who may be at risk for relapse (e.g., weight gain) in order to provide more early, targeted and ongoing intervention of these high risk individuals. An exploratory investigation was conducted to determine: (a) the relevance of using metabolomics in delivering non-invasive markers to predict an individual’s responsiveness to an immersion treatment program, and (b) to integrate psychosocial and metabolomic profiles that can further serve to predict an adolescent’s positive response to weight loss. Obese adolescents (12–18 years old, BMI >95th percentile) attending a 3 weeks immersion healthy lifestyle camp, Take Off 4-Health (TO4-H), were recruited to provide first morning void urine samples and to complete psychosocial and health-behavior inventories at baseline and at the end of the 3 weeks program. Subjects were categorized as responders (decline of ≥0.5 BMI units) or non-responders (decline of <0.5 BMI units) based on weight loss between baseline and the end of the 3 weeks program. Subjects were additionally classified as having either a healthy or impaired self-esteem (impaired ≥20 or healthy <20) and depression (impaired ≥15 or healthy <15) at baseline and the end of the 3 weeks camp-based on their responses to psychosocial inventories. NMR based metabolomics was used to generate signatures of low molecular components in urine. Using multivariate analysis of signals, findings demonstrated a unique pattern for treatment responders vs. non-responders. Moreover, inspection of loadings plots and variable importance plots enabled the identification of a subset of metabolites and psychosocial variables that may assist in our understanding and prediction of adolescent responsivity to treatment for weight loss. For the psychosocial variables, improvement in self-esteem and depression did not correlate with weight loss, multivariate analysis of urinary metabolomics data using healthy and impaired classifications for self-esteem and depression did enable the determination of subsets of metabolites that best associated with impaired self-esteem and depression. Integrating the metabolomic and psychosocial data provided a marker profile pointing to both biochemical (metabolite) and psychosocial indexes (self-esteem and depression) that are most relevant to determining an individual’s overall response to treatment. This study demonstrates the utility of metabolomics in providing non-invasive markers that upon validation in a larger sample may be an extremely important tool in the early detection and clinical management of adolescent obesity.

A cross-sectional study of breast cancer biomarkers among shift working nurses

ObjectivesIn 2007, the International Agency for Research on Cancer classified long-term shift work as a probable carcinogen, with the strongest evidence for breast cancer. One proposed mechanism involves night-time light...

Urinary inorganic arsenic in residents living in close proximity to a nickel and copper smelter in Ontario, Canada.

The current study determines whether internal exposure to inorganic arsenic for residents living in close proximity to an operating smelter is any different from that for residents living in a similar community without anthropogenic sources of inorganic arsenic. Furthermore, the study examines factors that may contribute to internal inorganic arsenic exposure in these populations. A cross-sectional study was used to determine whether recent internal exposure to inorganic arsenic for residents living in close proximity to an operating smelter with known elevated soil arsenic content is any different from exposure for residents living in a similar socio-demographic community without point sources of arsenic. Personal information was collected from participants during in-home interviews, and first morning void urine samples were obtained to assess recent internal exposure to arsenic. The mean concentration of urinary inorganic arsenic of residents living in the exposed community was 7.11 ug/L (Standard deviation (SD) 4.53, N = 368) and in the non-exposed community was 7.19 ug/L (SD 5.63, N = 321). The difference in urinary inorganic concentration was not statistically significant (p = 0.83). Regression analysis showed that age and sex were significant predictors of internal exposure, with males and younger age groups having higher exposure levels. Based on analyses of data collected, the results did not demonstrate a statistically significant difference in recent internal exposure to inorganic arsenic between the community with and the one without industrial or other point sources of environmental arsenic contamination. However, individual characteristics such as age and sex are important contributors to urinary inorganic arsenic levels.

Ethyl Glucuronide, Ethyl Sulfate, and Ethanol in Urine after Intensive Exposure to High Ethanol Content Mouthwash

To determine the degree of ethanol absorption and the resultant formation and urinary excretion of its conjugated metabolites following intensive use of high ethanol content mouthwash, 10 subjects gargled with Listerine(®) antiseptic 4 times daily for 3¼ days. First morning void urine specimens were collected on each of the four study days and post-gargle specimens were collected at 2, 4, and 6 h after the final gargle of the study. Urine ethanol, ethyl glucuronide (EtG), ethyl sulfate (EtS), and creatinine were measured. Ethanol was below the positive threshold of 20 mg/dL in all of the urine specimens. EtG was undetectable in all pre-study urine specimens, but two pre-study specimens had detectable EtS (6 and 82 ng/mL; 16 and 83 μg/g creatinine). Only one specimen contained detectable EtG (173 ng/mL; 117 μg/g creatinine). EtS was detected in the urine of seven study subjects, but was not detected in the single specimen that had detectable EtG. The maximum EtS concentrations were 104 ng/mL and 112 μg/g creatinine (in different subjects). Three subjects produced a total of eight (non-baseline) urinary EtS concentrations above 50 ng/mL or 50 μg/g creatinine and three EtS concentrations exceeding 100 ng/mL or 100 μg/g creatinine. In patients being monitored for ethanol use by urinary EtG and EtS concentrations, currently accepted EtG and EtS cutoffs of 500 ng/mL are adequate to distinguish between ethanol consumption and four times daily use of high ethanol content mouthwash.

A Comparative Study of Clinical Utility of Spot Urine Samples with 24-h Urine Albumin Excretion for Screening of Microalbuminuria in Type 2 Diabetic Patients

Twenty-four hour urinary albumin excretion (UAE) is considered as gold standard method for albuminuria measurement, but collection of 24-h urine is inconvenient. The aim of present study was to evaluate whether albumin: creatinine ratio (ACR) and urinary albumin concentration (UAC) in different spot urine samples correlate or not with 24-h UAE for screening of microalbuminuria in type 2 diabetic patients. We collected first morning void (FMV), random urine sample (RUS) and 24-h urine, separately on consecutive days from 104 type 2 diabetic patients. ACR and UAC in each spot urine sample compared with 24-h UAE with regard to Pearson correlation coefficient. Pearson's correlation of albumin: creatinine ratio (ACR) with 24-h UAE was (r=0.802 and 0.623) in first morning void (FMV) and random urine sample (RUS), respectively. Pearson's correlation coefficient of urinary albumin concentration (UAC) compared with 24-h UAE was (r=0.943 and 0.920), in FMV and RUS, respectively, P<0.01. Results revealed that values in first morning void (FMV) were better correlated with 24-h urinary albumin excretion (UAE), than the values in random urine sample (RUS). We conclude that the first morning void (FMV) may be able to replace 24-h urine collection, preferably urinary albumin concentration (UAC) in the initial screening of microalbuminuria in diabetic patients. The online version of this article (doi:10.1007/s12291-011-0136-0) contains supplementary material, which is available to authorized users.

Urinary excretion of phthalate metabolites in 129 healthy Danish children and adolescents: Estimation of daily phthalate intake

Background Phthalates are a group of chemicals with widespread use in the industrial production of numerous consumer products. They are suspected to be involved in male reproductive health problems and have also been associated with several other health problems in children including obesity and asthma. Objectives To study the urinary excretion of phthalate metabolites in Danish children recruited from the general population, and to estimate the daily intake of phthalates in this segment of the population. Method One 24 h urine sample and to consecutive first morning urine samples were collected from 129 healthy Danish children and adolescents (range 6–21 yrs). The concentrations of 11 phthalate metabolites of 5 different phthalate diesters were analyzed by liquid chromatography–tandem mass spectrometry. Results The analyzed metabolites were detectable in almost all 24 h urine samples. The median concentrations of monoethyl phthalate (MEP), monobenzyl phthalate (MBzP) and the sums of the two monobutyl phthalate isoforms (∑MBP( i+ n)), metabolites of di-(2-ethylhexyl) phthalate (∑DEHPm) and of di-iso-nonyl phthalate (∑DiNPm) were 29, 17, 111, 107 and 31 ng/mL, respectively. The youngest children were generally more exposed to phthalates than older children and adolescents (except diethyl phthalate (DEP)). Boys were more exposed than girls. The median estimated daily intake of phthalate diesters was: 4.29 (dibutyl phthalate isoforms (DBP( i+ n))), 4.04 (DEHP), 1.70 (DiNP), 1.09 (DEP) and 0.62 (butylbenzyl phthalate (BBzP)), all calculated as μg/kg body weight/24 h. Between 40% and 48% of the absolute amount of phthalate metabolites excreted over 24 h were excreted in first morning urine voids. Conclusion Danish children are exposed simultaneously to multiple phthalates. The highest exposure levels were found for DBP( i+ n) and DEHP, which in animal models are the known most potent anti-androgenic phthalates. The combined exposure to the two isoforms of DBP, which have similar endocrine-disrupting potencies in animal models, exceeded the TDI for di-n-butyl phthalate (DnBP) in several of the younger children.

Dual effect of adipose tissue on bone health during growth

Recent studies suggest association between body fat and childhood bone health, although conflicting findings have also been reported. The aim of the present study was to examine the association between body fat content and areal BMD, volumetric BMD, bone turnover markers, and calcitropic factors in apparently healthy children and adolescents. The study was carried out as a school based cross-sectional cohort study with 186 subjects (61% girls) aged from 7 to 19 years. Background characteristics, including medical history and lifestyle factors, were collected. Anthropometry, BMD and body composition measurements with DXA and pQCT, a fasting blood sample and a second morning void urine sample were obtained. The subjects were divided into three groups, representing low, intermediate and high adiposity, based on age and gender specific fat percentage Z-scores. Multivariate analysis was performed to all bone variables using lean body mass, pubertal development, dietary intake of calcium and intensity of physical activity as covariates. In pQCT, a significant difference between the groups was observed in cortical BMD (MANOVA; p = 0.02) in proximal radius, the intermediate group having the highest values. Similarly, DXA-derived LS and WB BMD Z-scores differed significantly between the groups (MANOVA; p = 0.026 and p = 0.036, respectively), with highest values in the intermediate group. High body fat content associated also with low bone turnover markers, low PTH, high S-Ca and high urinary calcium excretion. The differences in biochemical markers explain our and others' findings of bone health in children and adolescents with different body fat content. These findings suggest that normal body fat content is beneficial for bone health in growing children and adolescents while both low and high body fat content have adverse skeletal effects.

Selection on albuminuria enhances the efficacy of screening for cardiovascular risk factors

As many subjects with a cardiovascular (CV) risk factor are undiagnosed, guidelines to prevent cardiovascular disease argue for case finding on those risk factors. Such an approach is, however, labour and cost intensive. An elevated urinary albumin loss is an early marker of vascular damage and is associated with an increased CV risk. As albuminuria is easy to measure, we tested whether a screening approach in which detailed risk factor measurement is done only after selection of subjects with an elevated albuminuria results in a higher yield of subjects at risk. A random sample of the general population as investigated in the Prevention of Renal and Vascular End-Stage Disease study was used. Plasma glucose, blood pressure, serum cholesterol and renal function were measured in an overall random sample of the population, in subgroups according to their urinary albumin concentration (UAC) of one first morning urine void and in subgroups in whom the elevated albuminuria level was confirmed with two 24 h urine collections for measurement of urinary albumin excretion (UAE). In the overall population, the number of subjects with any newly found CV risk factor was higher than the number of subjects already known with any CV risk factor (n = 1331 versus 370; 39.2 versus 10.9%). The prevalence of subjects with any newly diagnosed CV risk factor was higher in the group of 267 subjects with a first morning UAC of ≥ 20 mg/L (61.0%; P < 0.05) compared to the overall population (39.2%). Although the sensitivity of a UAC ≥ 20 mg/L to detect a subject with at least one CV risk factor was relatively low (12%), the specificity was very high (96%). The positive predictive value was 70%. When the elevated UAC could be confirmed in two subsequent 24-h urine collections, the diagnostic yield still further improved. The prevalence of undiagnosed CV risk factors in the general population is much higher than the prevalence of known risk factors. After a selection of subjects with an elevated albuminuria, the relative prevalence of subjects with newly diagnosed CV risk factors increases while the number of subjects to test for presence of CV risk factors is smaller. Such an approach facilitates a more effective and simple strategy for risk factor screening.

Bone mass, vitamin D levels and immunosuppressive treatment in patients with liver transplant and risedronate treatment

As bone matures type I collagen undegoes β isomerisation at the DG motif of the CTX epitope. Measurements of αCTX and βCTX allow us to distinguish between bone turnover in newly formed and mature bone, respectively. In states of pathologically high bone turnover such as Paget's and malignant bone diseases, there is a relatively greater increase in the resorption of newly formed bone. Treatment of these with bisphosphonates results in a relatively greater decrease in the resorption of newly formed bone. The aims were to investigate 1) the relative increase in αCTX in postmenopausal osteoporosis and 2) the relative decrease in αCTX with bisphosphonate treatment. We recruited 60 postmenopausal women (mean age 68: range 55-85) with a BMD T-score of <2.5 or <1 and a fracture. They were randomised into 3 treatment groups: ibandronate (n=19), alendronate (n=23) and risedronate (n=18). 75 healthy premenopausal women (mean age 38: range 30-45) were recruited. We measured α and βCTX (Nordic Biosciences Diagnostics, Copenhagen, Denmark) in second morning void urine samples and serum βCTX (Roche Diagnostics, Pensberg, Germany). The median urinary α and βCTX and serum βCTX were significantly lower in healthy premenopausal compared to postmenopausal osteoporotic women at baseline 62%, 110% and 65% respectively (P<0.0001). The median urinary α and βCTX and serum βCTX showed a significant decrease by 68%, 88%, and 79% from baseline respectively (P<0.0001) after 13 weeks of treatment. The α/β CTX ratio increased by 62% (P<0.05). We conclude that resorption of type I collagen in postmenopausal osteoporosis is greater compared to healthy premenopausal women. There is no relative greater increase in the resorption of newly formed bone. With bisphosphonate treatment, the resorption of type I collagen is decreased after 13 weeks of treatment, but there is no greater decrease in the relative resorption of newly formed bone. In fact, there is a preferential decrease in the resorption of mature bone.

Reliability of spot urine samples in assessing arsenic exposure.

Urinary arsenic concentration is often used as a biomarker of arsenic exposure. First morning void (FMV) and spot urine samples from 131 participants in southeastern Michigan were analyzed using an HPLC-IC-PMS system for six different arsenic species: arsenobetaine (AsB), arsenite (As[III]), arsenate (As[V]), methylarsonous acid MMA[III], methylarsenic acid MMA[V], and dimethylarsenic DMA[V]. Bland-Altman plots, intraclass correlation coefficients (ICCs), and Pearson correlation procedures were used to evaluate the relationship between the arsenic species in FMV and spot urine collections after normalizing the samples by specific gravity. DMA[III] and MMA[III] were not detected in any of the samples. The sum of As[III], As[V], MMA[V], and DMA[V] was designated SumAs. The ICC between SumAs in FMV and SumAs in spot samples was 0.90. The ICC showed that 90% of variation comes from between individuals and not within individuals. A significant correlation (r=0.80 p<0.001) was observed between FMV and spot samples for SumAs. The spot sample were a good predictor of the MMA[V] (r=0.83 p<0.0001), and DMA[V] (r=0.77 p<0.0001) in the FMV sample. These associations suggest that either FMV or spot samples can be used as an adequate bioindicator of arsenic metabolites in human urine. The benefit of using spot urine samples, instead of 24-h or FMV urine samples, is the potential reduction in budgetary and logistic requirements in epidemiological studies.

Rationale and design of the Eplerenone combination Versus conventional Agents to Lower blood pressure on Urinary Antialbuminuric Treatment Effect (EVALUATE) trial: a double-blinded randomized placebo-controlled trial to evaluate the antialbuminuric effects of an aldosterone blocker in hypertensive patients with albuminuria

Although inhibitors of the renin-angiotensin system are effective as first-line antihypertensive drugs in hypertensive patients with chronic kidney disease, they cannot completely prevent the progression of renal injury. Many animal studies, including our own, and a few human studies suggest that mineralocorticoid receptor blockade could inhibit the ongoing renal damage in chronic kidney disease. Thus, we designed this double-blinded, randomized, placebo-controlled trial to evaluate the antialbuminuric effect of a low dose (50 mg day(-1)) of the mineralocorticoid receptor antagonist eplerenone. The study subjects will include 340 hypertensive patients (blood pressure: 130-180/80-100 mm Hg) with albuminuria (urinary albumin/creatinine ratio: 30-600 mg g(-1) in the first morning void urine), who are treated with an inhibitor of the renin-angiotensin system. Other classes of antihypertensive drugs may be added as needed to achieve the target blood pressure (<130/80 mm Hg). The primary study end point is the change in the urinary albumin/creatinine ratio after a 1-year study period. This trial is expected to show whether a low dose of mineralocorticoid receptor antagonists can exert an antialbuminuric effect in patients with chronic kidney disease.

Comparison of the yield of different screening approaches to detect chronic kidney disease

Screening for chronic kidney disease (CKD) has been advised in high-risk populations. The present study aims to compare the yields of four approaches to select high-risk subjects for CKD screening, which are defined as follows: Approach 1, history of cardiovascular (CV) disease, diabetes mellitus or hypertension (=high CV risk); Approach 2, high CV risk or age >55 years; Approach 3, urinary albumin concentration (UAC) ≥20 mg/L; or Approach 4, UAC ≥10 mg/L at pre-screening. The study population is a sample of the general population of Groningen, the Netherlands (n = 3398). UAC was measured (nephelometry) in a first morning void urine sample collected at home and sent to a laboratory by post. Information on demographics and the presence of CV risk factors was obtained by a questionnaire. The presence of CKD was determined during examination at an outpatient clinic. At baseline, 12% of the subjects met the criteria of Approach 1, 33% of Approach 2, 8% of Approach 3 and 25% of Approach 4. CKD was diagnosed in 370 subjects (11%). Approach 2 detected the most CKD patients (sensitivity 65%), while Approach 3 resulted in the lowest number needed to screen (1.9). During a follow-up of 7 years, only the UAC pre-screening approaches detected CKD patients who had both significantly accelerated renal function loss and increased CV risk compared to subjects without CKD. Only 28% of CKD patients detected by the UAC approaches used antihypertensive/angiotensin-converting enzyme inhibitor treatment prior to screening. This study suggests that pre-screening based on UAC should be favoured in comparison to screening based on CKD risk factors to detect CKD patients at high renal and CV risk.

A prospective study of protein excretion using short-interval timed urine collections in patients with lupus nephritis

The 24-h urine protein-to-creatinine ratio is the gold standard in evaluating proteinuria in lupus nephritis; however, the urine collection is inconvenient to the patient. Random spot urine protein-to-creatinine ratios, although convenient, have poor agreement with the 24-h ratios in these patients. Here, we sought to define a timed collection interval providing accurate and precise data and patient convenience. Urine from 41 patients, in 2 medical centers, with biopsy-proven lupus nephritis was collected at 6-h intervals for 24 h. The protein-to-creatinine ratio of each short collection was then compared with that of a 24-h collection made by combining the 6-h samples. A first morning void and spot urine samples were collected before and after the 24-h collection, respectively. There was significant diurnal variation with peak proteinuria at 6-12 h and nadir at 18-24 h. Each 6-h collection showed excellent correlation and concordance with the 24-h protein-to-creatinine ratio, but the 12-24-h interval had the best agreement. In contrast to the random spot urines, the first morning void also had excellent correlation and concordance, but underestimated the 24-h protein-to-creatinine ratio. Our study shows that a 12-h overnight urine collection is the best surrogate, with excellent agreement with the 24-h protein-to-creatinine ratio, and it is convenient for patients. There was little variability between centers, an important feature for clinical trials.

Evaluation of urinary arsenic as an indicator of exposure to residents of Tarkwa, Ghana

In Ghana, mining plays a significant role in the economic recovery programme. However, the gains are achieved at the cost of environmentaland human health. For many years, the extraction of gold involved roasting which released airborne particles and large quantities of arsenic(As). Sampling for this study was conducted in March 2004 to assess the contamination status of trace elements, especially As, in water andmine workers in Tarkwa, which has nearly a century of gold mining history. Water and human urine samples were collected from Tarkwa, inaddition to control samples taken from Accra, the capital of Ghana. Arsenic excretion was assessed in the first morning void urine. Concentrations of As and Mn in some water samples from Tarkwa were above the WHO drinking water guidelines. A potential health risk of As and Mn is a concern for the people consuming the contaminated water in this area. Levels of trace elements in water from control site were low compared to levels from Tarkwa. The mean urinary As concentration of 260 ìgl-1 from the study area was comparable to those in Asendemic areas of the world. This indicates relatively high degree of human exposure to As in Tarkwa, Ghana. Relatively low levels of As in water and no significant difference of As concentrations in urine between Tarkwa and Accra may suggest the presence of other sources of As contamination in Ghana, possibly food. This is the first study reporting 23 trace elements in human urine samples from a mining town in Ghana.

Evaluation of Cell-free DNA in Urine as a Marker for Bladder Cancer Diagnosis

The diagnosis and follow-up of bladder cancer are mainly based on cystoscopy, an invasive method which could be negative in case of flat malignancies such as carcinoma in situ. Other noninvasive diagnostic methods have not yet given satisfactory results. There is a need for a reliable yet noninvasive method for the detection of bladder cancer. Our aim was to investigate whether cell-free DNA quantified in urine (ucf-DNA) could be a useful marker for the diagnosis of bladder cancer. A standard urine test was performed in 150 naturally voided morning urine samples that were processed to obtain a quantitative evaluation of ucf-DNA. Leukocyturia and/or bacteriuria were found in 18 subjects, who were excluded from the study. Statistical analysis was performed on 45 bladder cancer patients and 87 healthy subjects. Ucf-DNA was extracted from urine samples by a spin column-based method and quantified using four different methods: GeneQuant Pro (Amersham Biosciences, Pittsburg, PA, USA), Quant-iT DNA high-sensitivity assay kit (Invitrogen, Carlsbad, CA, USA), Real-Time PCR (Applied Biosystems, Foster City, CA, USA), and NanoDrop 1000 (NanoDrop Technologies, Houston, TX, USA). Median free DNA quantification did not differ statistically between bladder cancer patients and healthy subjects. A receiver-operating characteristic (ROC) curve was developed to evaluate the diagnostic performance of ucf-DNA quantification for each method. The area under the ROC curve was 0.578 for GeneQuant Pro, 0.573 for the Quant-iT DNA high-sensitivity assay kit, 0.507 for Real-Time PCR, and 0.551 for NanoDrop 1000, which indicated that ucf-DNA quantification by these methods is not able to discriminate between the presence and absence of bladder cancer. No association was found between ucf-DNA quantification and tumor size or tumor focality. In conclusion, ucf-DNA isolated by a spin column-based method and quantified by GeneQuant Pro, Quant-iT DNA high-sensitivity assay kit, Real-Time PCR or NanoDrop 1000 does not seem to be a reliable marker for the diagnosis of bladder cancer.

Evaluation of cell-free DNA in urine as a marker for bladder cancer diagnosis

The diagnosis and follow-up of bladder cancer are mainly based on cystoscopy, an invasive method which could be negative in case of flat malignancies such as carcinoma in situ. Other noninvasive diagnostic methods have not yet given satisfactory results. There is a need for a reliable yet noninvasive method for the detection of bladder cancer. Our aim was to investigate whether cell-free DNA quantified in urine (ucf-DNA) could be a useful marker for the diagnosis of bladder cancer. A standard urine test was performed in 150 naturally voided morning urine samples that were processed to obtain a quantitative evaluation of ucf-DNA. Leukocyturia and/or bacteriuria were found in 18 subjects, who were excluded from the study. Statistical analysis was performed on 45 bladder cancer patients and 87 healthy subjects. Ucf-DNA was extracted from urine samples by a spin column-based method and quantified using four different methods: GeneQuant Pro (Amersham Biosciences, Pittsburg, PA, USA), Quant-iT DNA high-sensitivity assay kit (Invitrogen, Carlsbad, CA, USA), Real-Time PCR (Applied Biosystems, Foster City, CA, USA), and NanoDrop 1000 (NanoDrop Technologies, Houston, TX, USA). Median free DNA quantification did not differ statistically between bladder cancer patients and healthy subjects. A receiver-operating characteristic (ROC) curve was developed to evaluate the diagnostic performance of ucf-DNA quantification for each method. The area under the ROC curve was 0.578 for GeneQuant Pro, 0.573 for the Quant-iT DNA high-sensitivity assay kit, 0.507 for Real-Time PCR, and 0.551 for NanoDrop 1000, which indicated that ucf-DNA quantification by these methods is not able to discriminate between the presence and absence of bladder cancer. No association was found between ucf-DNA quantification and tumor size or tumor focality. In conclusion, ucf-DNA isolated by a spin column-based method and quantified by GeneQuant Pro, Quant-iT DNA high-sensitivity assay kit, Real-Time PCR or NanoDrop 1000 does not seem to be a reliable marker for the diagnosis of bladder cancer.