24-h Urine Samples Research Articles

Angiotensin II-induced renal angiotensinogen formation is enhanced in mice lacking tumor necrosis factor-alpha type 1 receptor.

In hypertension induced by angiotensin II (AngII) administration with high salt (HS) intake, intrarenal angiotensinogen (AGT) and tumor necrosis factor‐alpha (TNF‐α) levels increase. However, TNF‐α has been shown to suppress AGT formation in cultured renal proximal tubular cells. We examined the hypothesis that elevated AngII levels during HS intake reduces TNF‐α receptor type 1 (TNFR1) activity in the kidneys, thus facilitating increased intrarenal AGT formation. The responses to HS diet (4% NaCl) with chronic infusion of AngII (25 ng/min) via implanted minipump for 4 weeks were assessed in wild‐type (WT) and knockout (KO) mice lacking TNFR1 or TNFR2 receptors. Blood pressure was measured by tail‐cuff plethysmography, and 24‐h urine samples were collected using metabolic cages prior to start (0 day) and at the end of 2nd and 4th week periods. The urinary excretion rate of AGT (uAGT; marker for intrarenal AGT) was measured using ELISA. HS +AngII treatment for 4 weeks increased mean arterial pressure (MAP) in all strains of mice. However, the increase in MAP in TNFR1KO (77 ± 2 to 115 ± 3 mmHg; n = 7) was significantly greater (p < 0.01) than in WT (76 ± 1 to 102 ± 2 mmHg; n = 7) or in TNFR2KO (78 ± 2 to 99 ± 5 mmHg; n = 6). The increase in uAGT at 4th week was also greater (p < 0.05) in TNFR1KO mice (6 ± 2 to 167 ± 75 ng/24 h) than that in WT (6 ± 3 to 46 ± 16 ng/24 h) or in TNFR2KO mice (8 ± 7 to 65 ± 44 ng/24 h). The results indicate that TNFR1 exerts a protective role by mitigating intrarenal AGT formation induced by elevated AngII and HS intake.

Lower 24-h urinary potassium excretion is negatively associated with excessive daytime sleepiness in thegeneral population.

Uncertainty remains about the association of potassium (K) intake and sleepiness. Therefore, we aimed to explore the relationship between K excretion using 24-h urine samples and excessive daytime sleepiness (EDS) in the general population. In a cross-sectional study, we used multi-stage proportional random sampling to obtain a study sample aged ≥ 18years from Emin, China between March and June 2019. We collected timed 24-h urine specimens and conducted EDS assessments using the Epworth Sleepiness Scale (ESS) questionnaire. Subjects were divided into two groups by the median of 24-h urinary potassium (24-h UK). EDS was defined as ESS score ≥ 10. Multi-variable linear regression was used to examine the association between the 24-h UK and the odds of prevalent EDS. We performed a sensitivity analysis by excluding subjects under anti-hypertensive treatment and those with sleep disordered breathing by the NoSAS scale. A total of 470 participants with complete 24-h urine samples and ESS data (62% women, mean age 49.6years, mean ESS score of 9.0 ± 5.2) were enrolled. The mean ESS score was significantly lower in the upper half of 24-h UK group than in the lower half (9.5 ± 5.3 vs 8.5 ± 5.1, P = 0.044), and accordingly, prevalent EDS was significantly greater in the lower half than in the higher half (49% vs 40%, P = 0.039). In further improving the propensity matching score, the results remained consistent with the overall results. In multiple linear regression, 24-h UK was negatively correlated with ESS score (β = - 0.180 (- 0.276, - 0.085), < 0.001). Sensitivity analysis demonstrated augmented results in those without anti-hypertensive treatment. Lower potassium intake, as suggested by lower UK excretion, may be implicated in the presence of EDS in the general population.

Should pediatric idiopathic hypercalciuria be treated with hypocalciuric agents?

BACKGROUNDHypercalciuria is the most common metabolic risk factor for calcium urolithiasis and is associated with bone loss in adult patients. Reduced bone mineral density (BMD) was already described in idiopathic hypercalciuria (IH) children, but the precise mechanisms of bone loss or inadequate bone mass gain remain unknown. Life-long hypercalciuria might be considered a risk to change bone structure and determine low bone mass throughout life. The peak of bone mass should occur without interferences. A beneficial effect of citrate formulations and thiazides on bone mass in adult and pediatric patients with IH have been shown.AIMTo evaluate whether pharmacological therapy has a beneficial effect on bone mass in children and adolescents with IH.METHODSThis retrospective cohort study evaluated 40 hypercalciuric children non-responsive to lifestyle and diet changes. After a 2-mo run-in period of citrate formulation (Kcitrate) usage, the first bone densitometry (DXA) was ordered. In patients with sustained hypercalciuria, a thiazide diuretic was prescribed. The second DXA was performed after 12 mo. Bone densitometry was performed by DXA at lumbar spine (L2-L4). A 24-h urine (calcium, citrate, creatinine) and blood samples (urea, creatinine, uric acid, calcium, phosphorus, magnesium, chloride, hemoglobin) were obtained. Clinical data included age, gender, weight, height and body mass index.RESULTSForty IH children; median age 10.5 year and median time follow-up 6.0 year were evaluated. Nine patients were treated with Kcitrate (G1) and 31 with Kcitrate + thiazide (G2). There were no differences in age, gender, body mass index z-score and biochemical parameters between G1 and G2. There were no increases in total cholesterol, kalemia and magnesemia. Calciuria decreased in both groups after treatment. Lumbar spine BMD z-score increased after thiazide treatment in G2. There was no improvement in G1.CONCLUSIONResults point to a beneficial effect of thiazide on lumbar spine BMD z-score in children with IH. Further studies are necessary to confirm the results of the present study.

At-home determination of 24-h urine sodium excretion: Validation of chloride test strips and multiple spot samples.

Sodium intake and compliance with dietary sodium modification are typically assessed using a 24-h urine collection analyzed using flame photometry, but this is inconvenient. Spot urine samples have been investigated as alternatives to 24-h collections, but their accuracy is poor. Since sodium and chloride are present in equal concentrations in dietary salt, chloride test strips may provide a suitable proxy for at-home measurement of urine sodium concentrations. We aimed to determine whether (i) chloride test strips provide a reliable measure of urinary sodium compared to the gold standard flame photometry and (ii) multiple spot samples accurately reflect 24-h urine sodium. We recruited 43 participants (19 males) aged 23.6±0.6years to complete multiple consecutive spot samples (morning and evening) along with a 24-h urine sodium collection. Urine 24-h sodium estimates using chloride test strips (114.6±7.5mmol/day) were highly correlated (r=0.900, p<0.0001) with flame photometry (121.1±7.7mmol/day) with a bias of -6.53±22.2mmol/day. Use of a three-spot sample average (both morning and evening spot samples) with a correction factor applied (122.9±4.1mmol/day) provided a good approximation of 24-h sodium measured by flame photometry (125.6±9.0mmol/day), with a bias of -2.55±43.9mmol/day. Chloride test strips applied to a 24-h urine collection provide a highly accurate measure of urinary sodium excretion, permitting convenient at-home sample collection and analysis. Their application to multiple spot samples provides a reasonable approximation of sodium excretion that can be used to conveniently monitor attempts at dietary sodium manipulation, without the inconvenience of completing a 24-h urine sample.

Diagnostic usefulness of the spot urine sodium/potassium ratio in cirrhotic patients with ascites.

Background and aimsThe low-salt diet is considered important for control of ascites in cirrhotic patients. To validate whether the spot urine sodium (Na)/potassium (K) ratio could replace 24-h urine Na (uNa) excretion in assessing low-salt diet compliance.MethodsWe prospectively studied 175 patients. 24-h urine collection and spot urine collection were performed. Subsequently, 24-h uNa, urine creatinine (uCr), and spot urine Na and K were assessed. A complete urine collection was confirmed based on 24-h uCr excretion levels of 15mg/kg/day for men and 10mg/kg/day for women. The area under the receiver operating characteristic (AUROC) curve analysis was performed to evaluate the feasibility of spot urine Na/K ratio in predicting 24-h uNa greater than 78mmol/day.ResultsOut of 175 patients, 24-h urine samples were completely collected in 57 patients only. Moreover, urine samples were not completely collected in 118 patients because their 24-h uCr excretion level was less than the established criteria. In complete urine collection group, AUROC curve for spot urine Na/K ratio in predicting 24-h uNa greater than 78mmol/day was 0.874±0.051 (P<0.001). In the incomplete urine collection group, the AUROC was 0.832±0.039 (P<0.001). In complete urine collection group, the classical cutoff value greater than 1.0 of spot urine Na/K ratio showed 90.9% sensitivity and 56.0% specificity.ConclusionsThe spot urine Na/K ratio reflects 24-h uNa, but the AUROC value obtained in this study is lower than that of a previous study. Considered the large number of patients with incomplete urine collection, validating 24-h complete urine collection criteria is necessary.

MO597ESTIMATING INDIVIDUAL-LEVEL SODIUM INTAKE WITH REPEATED SPOT URINE SAMPLING

Abstract Background and Aims In daily clinical practice, individual-level sodium (Na) intake is often estimated by measuring Na excretion in a single 24h urine collection, but long-term Na balance studies indicate that 7 consecutive 24h urine collections are needed. However, this approach is not feasible in clinical settings. In this study, we investigate whether the use of repeated spot urine sampling is an appropriate alternative for repeated 24h urine collections. Method We performed a post-hoc analysis of a metabolic ward study in 8 healthy male adults who consumed a 7-day diet with a fixed amount of Na (200 mmol/d). Urine was collected in four daily intervals: 7-13h, 13-19h, 19-23h and 23-7h. After reaching steady state, we estimated Na intake with 1 and 3 consecutive 24h urine collections and 3-day spot urine sampling, using the Kawasaki formula with measured 24h urine creatinine excretion. Results: On day 5, mean 24h Na excretion matched intake, indicating that steady state was achieved (Fig A). Mean and standard deviation of absolute differences between estimated and measured Na intake (ΔNa) for each method were: 18.8 ±14.6 mmol (3 x spot urine 7-13h), 32.3 ±18.7 mmol (3 x spot urine 13-19h), 74.6 ±30.0 mmol (3 x spot urine 19-23h), 28.2 ±19.8 mmol (3 x spot urine 23-7h), 29.8 ±23.9 mmol (1 x 24h urine) and 22.9 ±11.3 mmol (3 x 24h urine) (Fig B). With the exception of the 19-23h spot urine collection period, the accuracy of 3-day spot urine sampling did not significantly differ from accuracy of 1 and 3 consecutive 24h urine collections. When combining the pre-night and morning spot urine collections (19-7h), the accuracy of the estimation did not improve (ΔNa 28.7 ±19.6 mmol). Conclusion 3-day spot urine sampling did not perform significantly different than 1 and 3 24h urine collections for estimation of individual-level Na intake. Adequately powered studies need to confirm whether repeated spot urine sampling is an accurate and low burden alternative to repeated 24h urine collections.

Effect of suramin on urinary excretion of diabetes-induced glomerular and tubular injury parameters in rats

Diabetes mellitus causes changes in metabolism of extracellular nucleotides acting through P2 receptors (P2Rs). This affects renal function and may lead to glomerular and tubular disturbances. We measured urinary excretion of nucleotides (ATP, ADP, AMP, UTP, UDP, UMP) in streptozotocin-induced diabetic rats (65 mg/kg, i.p., day 0) and the effects of P2Rs’ blockade by suramin (10 mg/kg, i.p., days +7, +14) on glomerular P2×7R expression and urinary excretion of glomerular (albumin, nephrin) and tubular (KIM-1, NGAL) injury markers, electrolytes, and oxidative stress markers (TBARS, 8-OHdG). Concentrations of nucleotides, specific proteins, electrolytes, and oxidative stress markers in 24-h urine samples collected in metabolic cages at days –1, +6 and +20 were measured using ion-paired reversed-phase HPLC, immunoenzymatic and fluorometric methods, and flame photometry, respectively. Expression of KIM-1 and P2×7R was examined by immunohistochemistry or immunoblotting. Diabetes was associated with increased urinary excretion of ATP, ADP, UTP, UDP and glomerular P2×7R expression. Suramin attenuated P2×7R expression but did not affect urinary excretion of nucleotides. Urinary excretion of albumin, nephrin, NGAL, and 8-OHdG were increased in diabetic rats and were not affected by suramin. TBARS was higher in diabetic rats and suramin attenuated the excretion dynamics in this group. KIM-1 excretion was higher in diabetic rats and suramin further increased excretion of KIM-1 in both diabetic and non-diabetic rats. Furthermore, suramin attenuated the diabetes-induced natriuresis and kaliuresis. It is possible that suramin affects both glomerular and tubular functions in diabetic rats.

G Protein‐Coupled Estrogen Receptor 1 is Required for Greater Endothelin‐1 Excretion in Female Mice

Estrogen signaling via G protein-coupled estrogen receptor 1 (GPER1) can elicit cardiovascular and renal protective actions. Endothelin-1 (ET-1) is a pro-natriuretic peptide that contributes to sex differences in blood pressure regulation and Na+ homeostasis. We recently showed that activation of GPER1 in the renal medulla promotes ET-1-dependent natriuresis in female but not male rats. Also, renal GPER1 expression is significantly higher in female rats than in male rats. In the current study, we hypothesized that genetic deletion of GPER1 would elevate blood pressure and impair renal ET-1 production/release in a sex-specific manner. Twelve-week-old male and female GPER1-knockout (KO) and wild-type (WT) littermate mice were implanted with telemeters to monitor blood pressure. Parallel groups of mice were placed into metabolic cages, and 24-h urine samples were collected while food and water intake were monitored. Then, animals were euthanized to obtain plasma. Urinary levels of electrolytes and ET-1 were measured. GPER1 deletion did not significantly affect mean arterial blood pressure in female (KO: 102±1 mmHg; WT: 102±2 mmHg; n=7-8/group, p=0.9) or male mice (KO: 106±3 mmHg; WT: 106±2 mmHg; n=6-10/group, p=1). No genotypic differences were observed in food intake, water intake, or urine flow rate. GPER1 deletion did not significantly affect urinary Na+excretion in female (KO: 0.25±0.05 μg/24 h; WT: 0.17±0.05 μg/24 h; n=9-12/group, p=0.52) or male mice (KO: 0.34±0.06 μg/24 h; WT: 0.35±0.04 μg/24 h; n=10-12/group, p=1.00). Similarly, GPER1 deletion did not affect urinary K+ excretion in either sex. However, GPER1 deletion decreased urinary ET-1 excretion in females (KO: 75.16±16.35 ng/24 h; WT: 172.83±24.67 ng/24 h; n=6-10/group, p<0.005) but not males (KO: 95.18±17.52 ng/24 h; WT: 76.03± 9.90 ng/24 h; n=10-12/group, p=0.69). Of note, WT females had significantly greater urinary ET-1 excretion than WT males (p=0.001), whereas KO mice had no sex differences in ET-1 excretion. Importantly, urinary excretion of ET-1 reflects intrarenal ET-1 production/release. GPER1 deletion did not significantly change plasma ET-1 concentration in either sex. Finally, GPER1 deletion did not affect urinary aldosterone excretion in females (KO: 315.98±73.13 pg/24 h; WT: 306.79±81.45 pg/24 h; n=7-8, p=1.00) or males (KO: 544.09±130.20 pg/24 h; WT: 481.84±68.30 pg/24 h; n=8/group, p=0.87). However, male mice had significantly greater urinary aldosterone excretion than female mice (p=0.04), regardless of genotype. Overall, we demonstrate that WT female mice have higher urinary ET-1 excretion than WT males, and that GPER1 deletion eliminates this sex-related difference in intrarenal ET-1 production/release. Our data suggest that GPER1 may contribute to the enhanced capacity of the female kidney to maintain Na+ homeostasis and have led us to hypothesize this as a mechanism for protecting females against salt-sensitive hypertension.

Food sources of iodine in schoolchildren and relationship with 24-h urinary iodine excretion in Victoria, Australia.

Dietary recalls have been used previously to identify food sources of iodine in Australian schoolchildren. Dietary assessment can provide information on the relative contributions of individual food groups which can be related to a robust objective measure of daily intake (24-h urinary iodine excretion (UIE)). In Australia, the government has mandated the use of iodised salt in breadmaking to address iodine deficiency. The aim of this study was to determine the dietary intake and food sources of iodine to assess their contribution to iodine excretion (UIE) in a sample of Australian schoolchildren. In 2011-2013, UIE was assessed using a single 24-h urine sample and dietary intake was assessed using one 24-h dietary recall in a convenience sample of primary schoolchildren from schools in Victoria, Australia. Of the 454 children with a valid recall and urine sample, 55 % were male (average age 10·1 (1·3 (sd) years). Mean UIE and dietary iodine intake were 108 (sd 54) and 172 (sd 74) μg/d, respectively. Dietary assessment indicated that bread and milk were the main food sources of iodine, contributing 27 and 25 %, respectively, to dietary iodine. Milk but not bread intake was positively associated with UIE. Multiple regression (adjusted for school cluster, age and sex) indicated that for every 100 g increase in milk consumption, there was a 3 μg/d increase in UIE (β = 4·0 (se 0·9), P < 0·001). In conclusion, both bread and milk were important contributors to dietary iodine intake; however, consumption of bread was not associated with daily iodine excretion in this group of Australian schoolchildren.

Role of Osteoprotegerin as Novel Marker in Urinary Stone Formers: A Pilot Study

Background: Urinary tract calculus formation can be prevented by identifying molecules and metabolic disturbances that affect this process. Osteoprotegerin (OPG), a cytokine of the TNF receptor superfamily, has been demonstrated to mediate vascular calcification and intimal calcification. Endothelial injury and oxidative stress are known to play a role in urolithiasis in the form of Randall’s plaques. Objectives: The present study aimed to compare 24-h urinary and serum OPG levels of patients with and without urolithiasis. Methods: In this case-control study, 24-h urinary levels of OPG (pg/mL), serum levels of OPG (pg/mL), and creatinine (mg/dL) were measured in both groups. Urinary and serum levels of OPG were determined by enzyme-linked immunosorbent assay (ELISA) using human OPG kits. Results: Mean serum creatinine was 0.86 ± 0.21 mg/dL in the case group and 0.77± 0.16 mg/dL in controls. The difference in the mean serum OPG levels between the cases (227.13 ± 98.02 pg/mL) and controls (47.28 ± 29.61 pg/mL) was highly significant (P value &lt; 0.0001). The difference in the mean 24-h urinary OPG levels between the cases (156.12 ± 174.31 pg/mL) and controls (9.32 ± 23.72 pg/mL) was highly significant (P value &lt; 0.001). Conclusions: There were significantly higher levels of OPG in serum and 24-h urine samples of cases than in controls. Hence, it requires further large studies to make OPG a diagnostic and prognostic marker.

Determination of semicarbazide residue in human urine samples using liquid chromatography-tandem mass spectrometry

ABSTRACT An ultra-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry (UPLC-ESI-MS/MS) with pre-column derivatisation was developed and validated for the determination of semicarbazide in human urine. Urine samples were derivatised with 2-nitrobenzaldehyde and subsequently extracted with acetonitrile. Extracts were concentrated and then analysed by UPLC-MS/MS. The time per run was 7 min. Good results were observed for the linearity of matrix-matched calibration curves (R2 > 0.99) in the concentration range of 1–100 µg/L. The absolute recovery ranged from 98.7% to 108.6%, with the relative standard deviations (RSDs) of 2.2%-3.6%. The limit of detection and quantification for the semicarbazide was 0.5 µg/L and 1 µg/L, respectively. The method showed good extraction efficiency, high sensitivity, and good reproducibility. It was suitable for the detection of semicarbazide in human urine. Residues of semicarbazide were between 1.0 and 41.5 μg/L in children’s 24-h urine. This work is the first report on the quantitative analysis of SEM in 24-h human urine samples.

Evaluation of sirtuin 1 (SIRT1) levels in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease and the majority of patients have a PKD-1 or PKD-2 mutation. Sirtuin 1 (SIRT1) has roles in cellular aging, antioxidant activity, cellular proliferation. In an experimental study, inhibition of SIRT1 was found to delay renal cyst development in ADPKD. The purpose of this study is to determine the SIRT1 levels in ADPKD patients. To our knowledge, this is the first study that investigating blood and urine SIRT1 levels in ADPKD patients. Sixty-seven patients with ADPKD and 34 control cases with normal renal functions and without renal cysts were included in this study. Serum and urine SIRT1 concentrations were determined by human enzyme-linked immunosorbent assay (ELISA) kit. 24-h urine samples were used for urine SIRT1 measurements. The urine SIRT1 levels were statistically significantly lower in ADPKD patients group (p < 0.001). Although blood SIRT1 levels of ADPKD patients were higher than control cases but there were no statistically significant difference between the groups in terms of blood SIRT1 levels. Urine SIRT1 levels (β = 2.452, CI 95% 1.419-4.239, p = 0.001) were found an independent factor in multivariate regression analysis for ADPKD. Urine SIRT1 levels were lower in ADPKD patients than control group. The low urinary SIRT1 levels despite the similar blood SIRT1 levels might be due to the impaired metabolism of SIRT1 in ADPKD patients; this state might has a role in cyst development.

Association between 24-h urinary sodium to potassium ratio and mild cognitive impairment in community-based general population.

To explore the relationship between parameters of Na and K excretion using 24-h urine sample and mild cognitive impairment (MCI) in general population. This is a cross-sectional study. Community-based general population in Emin China. Totally, 1147 subjects aged ≥18 years were selected to complete the study, with a multistage proportional random sampling method. Cognitive status was assessed with Mini Mental State Examination (MMSE) questionnaire and timed 24-h urine specimens were collected. Finally, 561 participants aged ≥35 years with complete urine sample and MMSE data were included for the current analysis and divided into groups by tertiles of 24-h urinary sodium to potassium ratio (24-h UNa/K) as lowest (T1), middle (T2) and highest (T3) groups. The MMSE score was significantly lower in T3, compared with the T1 group (26·0 v. 25·0, P = 0·002), and the prevalent MCI was significantly higher in T3 than in T1 group (11·7 % v. 25·8 %, P < 0·001). In multiple linear regression, 24-UNa/K (β: -0·184, 95 % CI -0·319, -0·050, P = 0·007) was negatively associated with MMSE score. In multivariable logistic regression, compared with T1 group, 24-h UNa/K in the T2 and T3 groups showed 2·01 (95 % CI 1·03, 3·93, P = 0·041) and 3·38 (95 % CI 1·77, 6·44, P < 0·001) fold odds for presence of MCI, even after adjustment for confounders. More augmented results were demonstrated in sensitivity analysis by excluding individuals taking anti-hypertensive agents. Higher 24-h UNa/K is in an independent association with prevalent MCI.

DATA FROM A POPULATION INTERVENTION STUDY FOR THE REDUCTION OF SALT INTAKE AND ACQUISITION OF HEALTHY FOOD HABITS

Objective: Salt restriction and potassium (K) intake can lower blood pressure (BP) and reduce the risk for cardiovascular (CV) diseases. However, it is still unclear which approaches are most effective in changing diet behavior. We evaluated the impact of two education prevention programs in promoting healthy eating habits in the general population. Design and method: A total of 311 adults (20–70 years) responsible for acquiring and making their meals were randomly assigned to one of the 2 multi-component educational programs (intervention and healthy lifestyle) during 12 weeks, consisting in face-to-face sessions, e-learning and telephone contacts. The healthy lifestyle program was an integrated approach addressing healthy food and lifestyle habits, including increase in K intake, while intervention was based on education and motivation strategies for reducing salt consumption. Training and clinical evaluation sessions occurred every 4 weeks and 24-h urine samples were collected at beginning and after 12 weeks. Results: 269 subjects completed the study (71% women, mean age of 45 years). Groups were similar (mean values) at baseline: weight 75 Kg, BMI 27 kg/m2, waist 86 cm, salt intake 9.2 g/d, K+ 1.9 g/d and BP 116/74 mmHg. After 12 weeks the intake per week of vegetables and legumes doubled, while consumption increased of fruits and fish (50%) and of shellfish (30%) along with reduction of salty (6%) and processed foods (20%). After 12 weeks clinical improvements were similarly observed with both programs: reduction of BP by 2/2 ± 11/7 mmHg P &lt; 0.01, body weight by 0.3 ± 2.1 Kg, P = 0.007) and Na/K ratio by 0.05 ± 0.36, P = 0.027). Benefits were greater in subjects eating salt above mean (from 10.3 g/d salt/d salt intake reduced by 0.6 ± 1.5 g/d; P = 0.001), eating K+ bellow the median (from 2.1 g/d K intake increased 0.1 ± 0.2 g/d; P &lt; 0.001) and with BP above 130/85 mmHg (from 136/88, BP reduced 6/5 ± 14/8 mmHg P = 0.001). Conclusions: Both education programs showed a positive impact in weight, salt and K+ intakes and BP. Subjects with higher BP and / or salt intake were those who benefited most from these dietary approaches.

Low awareness of high sodium intake among older Chinese people.

Awareness is one of the first steps in a lifestyle modification process. Since older adults are at a higher risk of hypertension, maintaining low sodium intake is of utmost importance. Yet, it is uncertain if older adults have an awareness of their sodium intake. This study aimed to explore self-perceived sodium intake among older Chinese people and compare it with various measures of sodium intake. A cross-sectional study was conducted in Hong Kong in 2015. Data were collected from 24-h urinary sodium excretion (UNa24) measurements, dietary sodium intake by 24-h diet recalls and self-perceived salt intake levels among the older Hong Kong population. Kappa statistics and a paired t-test were used to compare the different measures. Fifty-nine participants provided complete 24-h urine samples. The mean (±SD) UNa24 of participants was 2846 ± 1253 mg, of which 74.6% exceeded the recommended daily sodium intake. About 87.8% of participants with UNa24 values >2000 mg perceived their sodium intake as too little or just right. The kappa statistic between UNa24 and self-perception was insignificantly different from zero (κ = -0.003, p-value = 0.909). The UNa24 estimates were significantly higher than those estimated from the 24-h diet recalls by 1203 mg (p-value <0.001). The findings imply that the low awareness of excessive sodium intake should be raised among older people to promote a healthy intake of sodium.

Reliability of urinary charged metabolite concentrations in a large-scale cohort study using capillary electrophoresis-mass spectrometry

Currently, large-scale cohort studies for metabolome analysis have been launched globally. However, only a few studies have evaluated the reliability of urinary metabolome analysis. This study aimed to establish the reliability of urinary metabolomic profiling in cohort studies. In the Tsuruoka Metabolomics Cohort Study, 123 charged metabolites were identified and routinely quantified using capillary electrophoresis-mass spectrometry (CE-MS). We evaluated approximately 750 quality control (QC) samples and 6,720 participants’ spot urine samples. We calculated inter- and intra-batch coefficients of variation in the QC and participant samples and technical intraclass correlation coefficients (ICC). A correlation of metabolite concentrations between spot and 24-h urine samples obtained from 32 sub-cohort participants was also evaluated. The coefficient of variation (CV) was less than 20% for 87 metabolites (70.7%) and 20–30% for 19 metabolites (15.4%) in the QC samples. There was less than 20% inter-batch CV for 106 metabolites (86.2%). Most urinary metabolites would have reliability for measurement. The 96 metabolites (78.0%) was above 0.75 for the estimated ICC, and those might be useful for epidemiological analysis. Among individuals, the Pearson correlation coefficient of 24-h and spot urine was more than 70% for 59 of the 99 metabolites. These results show that the profiling of charged metabolites using CE-MS in morning spot human urine is suitable for epidemiological metabolomics studies.

The impact of baseline potassium intake on the dose-response relation between sodium reduction and blood pressure change: systematic review and meta-analysis of randomized trials.

Sodium and potassium appear to interact with each other in their effects on blood pressure with potassium supplementation having a greater blood pressure lowering-effect when sodium intake is high. Whether the effect of sodium reduction on blood pressure varies according to potassium intake levels is unclear. We carried out a systematic review and meta-analysis to examine the impact of baseline potassium intake on blood pressure response to sodium reduction in randomized trials in adult populations, with sodium and potassium intake estimated from 24-h urine samples. We included 68 studies involving 5708 participants and conducted univariable and multivariable meta-regression. The median intake of baseline potassium was 67.7 mmol (Interquartile range: 54.6-76.4 mmol), and the mean reduction in sodium intake was 128 mmol (95% CI: 107-148). Multivariable meta-regression that included baseline 24-h urinary potassium excretion, age, ethnicity, baseline blood pressure, change in 24-h urinary sodium excretion, as well as the interaction between baseline 24-h urinary potassium excretion and change in 24-h urinary sodium excretion did not identify a significant association of baseline potassium intake levels with the blood pressure reduction achieved with a 50 mmol lowering of sodium intake (p > 0.05 for both systolic and diastolic blood pressure). A higher starting level of blood pressure was consistently associated with a greater blood pressure reduction from reduced sodium consumption. However, the nonsignificant findings may subject to the limitations of the data available. Additional studies with more varied potassium intake levels would allow a more confident exclusion of an interaction.

New Advanced Glycation End Products Observed in Rat Urine by Untargeted Metabolomics after Feeding with Heat-Treated Skimmed Milk Powder.

Milk powder is commonly consumed throughout the world. However, advanced glycation end products (AGEs) will form in milk powder during thermal processing and long-term storage. This study aimed to identify such compounds with potential as new urinary biomarkers of intake of heat-treated skimmed milk powder (HSMP). A parallel study is performed with different dosages of HSMP as well as hydrolyzed HSMP and untreated skimmed milk powder (SMP) in 36 rats. The 24-h urine samples on day 7 or 8 are collected and profiled by untargeted UPLC-Qtof-MS metabolomics. Statistical analysis revealed 25 metabolites differentiating SMP and HSMP; nineteen of these structures are proposed as lysine- and arginine-derived AGEs, and heterocyclic compounds. These metabolites may potentially serve as biomarkers of food intake pending further validation to assess intakes of heat-processed dairy foods and thus help to elucidate the effects of HSMP consumption or dietary AGEs on human health.

Role of Calcium/Creatinine Ratio in Urine Compared with Proteinuria and Uric Acid in Predicting Preeclampsia: A Study from Kosovo

BackgroundPreeclampsia is a common complication of pregnancy and a major cause of morbidity and mortality of mothers and babies worldwide. This study aimed to explore what the role of calcium/creatinine ratio is in urine compared with proteinuria and uric acid in predicting preeclampsia.Material/MethodsIn this prospective case-control study, 200 pregnant women who participated in the study were consecutively divided into 3 groups: a group of 59 women with preeclampsia, 61 women with pregnancy-induced hypertension, and a control group of 80 normotensive pregnant women. A 24-h urine sample was collected for estimation of calcium/creatinine ratio and proteinuria and a blood sample for estimation of uric acid at a gestational age of 24–34 weeks of pregnancy.ResultsThe study found that the sensitivity of proteinuria as a predictor of preeclampsia was 96.6% (P=0.000) and specificity was 21.3%. The sensitivity of uric acid as a predictor was 96.6% (P=0.000) and the specificity was 48.8%; whereas for the 24-h urine calcium/creatinine ratio, the sensitivity was 87.9% (P=0.000) and the specificity 40.7%, which corresponds to a value of 0.105 (cutoff). Women with a calcium/creatinine ratio <0.105 have a higher risk of developing preeclampsia (87.9% confidence interval, P=0.000).ConclusionsThe role of the calcium/creatinine ratio in urine is inferior to proteinuria and uric acid in predicting preeclampsia.

Urinary sodium excretion and dietary sources of sodium intake in community-dwelling Chinese adults aged 50 years and over.

This study examined Na intake and identified the major food sources of Na in healthy Chinese adults aged ≥50 years in Hong Kong. Participants who completed a baseline assessment of a randomised controlled trial assessing the effectiveness of exercise and nutrition supplementation on improving physical and cognitive functions were included. A single 24-h urine sample and a 3-d diet record were used to measure urinary Na excretion and dietary intake, respectively. The compliances to the WHO (<5 g/d) and China Nutrition Society (<6 g/d) recommendations for salt intake were assessed based on the urinary Na excretion. The relative contribution of sixteen food groups to the dietary Na intake was expressed as percentages. Associations between food groups and urinary Na excretion were analysed using multiple linear regression. Community facilities. Totally, 114 healthy Chinese adults (mean age 60·6 years, 55 % women). The mean urinary Na excretion over 24-h was 2876·6 ± 1249·4 mg/d (7·3 ± 3·2 g salt/d). Overall, 22·8 % of participants met the WHO recommendation and 34·2 % met the Chinese Nutrition Society recommendation for salt intake. The major food sources of dietary Na intake were condiments (42·4 %), cereals and their products (16·8 %) and soups (13·5 %). Higher intakes of seafood and nuts were associated with lower urinary Na excretion. Public health strategies should target healthy Chinese adults in Hong Kong to modify the current patterns of Na intake. Targeting condiments, cereals and their products and soups will be an important strategy to reduce their Na intake.