Sodium intake is correlated with the development of hypertension. Guyton's principals suggest that the 24-hour urinary sodium excretion reflects sodium ingestion over the same period. 24-hour urine ...collections are arduous to collect, so many centers use spot urinary measurements instead. We compared spot to matched 24-hour urinary electrolyte measurements.
We examined 419 hypertensive patients from the UCL Complex Hypertension Clinic. 77 had matched and complete 24-hour and spot urinary and serum biochemistry to examine.We compared the spot and 24-hour urinary; sodium concentration, Na/Cr ratio, FENa, Kawasaki and Tanaka estimated sodium excretion as well as the potassium concentration, K/Cr ratio, Kawasaki and Tanaka potassium excretion.
Our cohort was 58% male and the median age was 41 years. The 24-hour and spot Na concentrations correlated moderately (r = 0.4633, P < 0.0001). The 24-hour and spot Na/creatinine ratios correlated weakly (r = 0.2625, P = 0.0194). The 24-hour and spot FENa results showed a weak negative correlation (r = -0.222, P = ns). The 24-hour sodium excretion and the Kawasaki-derived spot urine sodium excretion correlated moderately (r = 0.3118, P = 0.0052). All Bland-Altman analyses showed poor agreement.The 24-hour and spot potassium concentrations correlated very poorly (r = 0.1158, P = ns). The 24-hour and spot urinary K/creatinine ratios correlated weakly (r = 0.47, P ≤ 0.0001). 24-hour and Kawasaki and Tanaka estimated potassium excretions correlated much better (r = 0.58, P < 0.0001).
Spot urinary measurements of sodium give a very poor understanding of the natriuresis occurring over the same 24-hour period. The Kawasaki and Tanaka estimations of the 24-hour sodium excretion showed a much lower correlation than previously reported.
BACKGROUND AND OBJECTIVES:Although 24-h urinary measure to estimate sodium and potassium excretion is the gold standard, it is not practical for large studies. We compared estimates of 24-h sodium ...and potassium excretion from a single morning fasting urine (MFU) using three different formulae in healthy individuals.
METHODS:We studied 1083 individuals aged 35–70 years from the general population in 11 countries. A 24-h urine and MFU specimen were obtained from each individual. A subset of 448 individuals repeated the measures after 30–90 days. The Kawasaki, Tanaka, and INTERSALT formulae were used to estimate urinary excretion from a MFU specimen.
RESULTS:The intraclass correlation coefficient (ICC) between estimated and measured sodium excretion was higher with Kawasaki (0.71; 95% confidence interval, CI0.65–0.76) compared with INTERSALT (0.49; 95% CI0.29–0.62) and Tanaka (0.54; 95% CI0.42–0.62) formulae (P <0.001). For potassium, the ICC was higher with the Kawasaki (0.55; 95% CI0.31–0.69) than the Tanaka (0.36; 95% CI−0.07 to 0.60; P <0.05) formula (no INTERSALT formula exists for potassium). The degree of bias (vs. the 24-h urine) for sodium was smaller with Kawasaki (+313 mg/day; 95% CI+182 to +444) compared with INTERSALT (−872 mg/day; 95% CI−728 to −1016) and Tanaka (−548 mg/day; 95% CI−408 to −688) formulae (P <0.001 and P = 0.02, respectively). Similarly for potassium, the Kawasaki formula provided the best agreement and least bias. Blood pressure correlated most closely and similarly with the 24-h and Kawasaki estimates for sodium compared with the other two formulae.
CONCLUSION:In a diverse population, the Kawasaki formula is the most valid and least biased method of estimating 24-h sodium excretion from a single MFU and is suitable for population studies.
Twenty-four-hour urinary total protein excretion is an essential parameter used for evaluation of renal function and early detection of gestational complications. However, data on reference ranges of ...24-hour urinary total protein excretion in normal pregnancy are scarce.
This study aimed to determine reference ranges for 24-hour urinary total protein excretion in a population with uncomplicated singleton pregnancies using a standard method for urinary total protein. In addition, the values of 24-hour urinary total protein were stratified by maternal age and prepregnancy body mass index.
This study was based on a prospective cohort study in Shenzhen, China. The pregnant women were enrolled at their first prenatal clinical visit. All the participants were instructed to collect 24-hour urine samples during the following successive gestational periods: 6
to 13
, 14
to 27
, and 28
to 41
weeks. Total urinary protein excretion was analyzed by a colorimetric method. Ultimately, the study encompassed a total of 4844 pregnant women with uncomplicated pregnancies. The nonparametric percentile method was used to determine reference ranges for 24-hour urinary total protein excretion during different trimesters in women with uncomplicated pregnancies (excluding those with previous kidney disorders, gestational or chronic hypertension, preeclampsia, and pregestational diabetes mellitus, among others).
The 24-hour urinary total protein levels expressed as medians and percentiles (5th, 95th) for each trimester were as follows: 72.0 (28.4, 165.0), 88.0 (34.0, 185.0), and 108.0 (37.5, 258.0) mg in the first, second, and third trimesters, respectively. A significant increase in 24-hour urinary total protein excretion was observed throughout pregnancy (all P values <.001). Moreover, 24-hour urinary total protein levels were higher in the older (≥35 years) than in the younger (<35 years) group from mid-gestation. Specifically, the median (interquartile range) 24-hour urinary total protein levels by age were 72.2 (50.6-100.0) vs 70.5 (50.5-100.0) mg, 85.8 (62.0-117.0) vs 96.0 (68.0-127.8) mg, and 106.6 (76.0-146.2) vs 114.7 (81.5-153.6) mg in the first, second, and third trimesters, respectively. In addition, 24-hour proteinuria was significantly increased in higher-weight (overweight or obese) subgroups compared with lower-weight (underweight or normal-weight) subgroups (all P values <.05).
Our study provides reference values for 24-hour urinary total protein excretion with apparently uncomplicated pregnancies. Understanding these changes in low-risk pregnancies is essential for optimizing maternal management.
Leafhoppers, a large hemipteran family, have a unique behavior of covering themselves with brochosomes. Brochosomes are believed to act as a protective coating for leafhoppers, serving to enhance ...hydrophobicity and provide protection against predators and parasites. In this study, we investigated the distribution, synthesis, and release mechanisms of brochosomes in the rice pest, Maiestas dorsalis. We found uniform brochosome coverage on different body parts and observed the step-by-step process of brochosome synthesis in the Malpighian tubules. Additionally, we identified a rapid and efficient mechanism for the release of brochosomes. Our study provides valuable insights into the synthesis and release mechanisms of brochosomes, enhancing our understanding of leafhopper biology. The leafhopper family Cicadellidae, comprising over 22,000 species, exhibits a unique behavior of anointing their bodies with excretions containing brochosomes. Brochosomes are synthesized in the distal segment of the Malpighian tubules and serve various functions, including hydrophobic protection and defense against pathogens and predators. In this study, we investigated the distribution, synthesis, and release mechanisms of brochosomes in the rice pest leafhopper Maiestas dorsalis. Using SEM and TEM, we observed brochosomes’ consistent coverage on the integument throughout the insect’s life cycle. Moreover, we identified four distinct developmental stages of brochosome synthesis within the distal segment of the Malpighian tubules, originating from the Golgi region. Most importantly, our research revealed a novel and highly efficient release mechanism involving the fusion of brochosome-containing vesicles, leading to a rapid and substantial release of brochosomes into the tubule lumen after molting. These findings shed light on the intricate processes of brochosome synthesis and release in leafhoppers, offering valuable insights into their functional significance and ecological role in these fascinating insects.
Recovery of submerged macrophytes has been considered a key factor in the restoration of shallow eutrophic lakes. However, in some subtropical restored lakes, small omnivorous fish dominate the fish ...assemblages and feed in part on submerged macrophytes. Knowledge of the effects of small omnivores on the growth of submerged macrophytes is scarce and their responses are potentially species-specific, i.e. the growth of some species may be hampered by fish grazing while growth of others may be promoted by the nutrients becoming available by fish excretion. We conducted mesocosm experiments to examine the effects of the small omnivorous bitterling Acheilognathus macropterus, a common species in restored subtropical lakes in China, on nutrient concentrations and the growth of four species of submerged macrophytes (Hydrilla verticillata, Vallisneria denseserrulata, Ceratophyllum demersum and Myriophyllum spicatum). We found that the bitterling significantly increased nutrient concentrations via excretion and thereby enhanced the net growth of the less grazed nuisance macrophyte M. spicatum. In contrast, the net growth of C. demersum was reduced by the bitterling, most likely due to grazing as indicated by gut content analyses. Dominance by bitterling may, therefore, pose a threat to the long-term success of lake restoration by provoking a shift in the submerged macrophyte community towards nuisance species through selective grazing. Nutrient excretion may potentially also stimulate the growth of phytoplankton and periphyton, hampering the growth of submerged macrophyte.
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•Effects of bitterling (A. macropterus) on macrophytes were studied in mesocosms.•Bitterling increased nutrient concentrations in the water column through excretion.•C. demersum and M. spicatum growth decreased and increased, respectively, with fish.•Bitterling dominance may disturbingly alter submerged macrophyte communities.
Although firefighters are at an increased risk of occupational exposure to chemicals, such as flame retardants, research on the exposure of Korean firefighters to organophosphate esters (OPEs)—a ...group of emerging flame retardants—remains limited. Therefore, in the present study, OPE metabolite concentrations in the urine samples of 149 former and current Korean firefighters were measured. Based on the data obtained, the estimated daily intakes (EDIs) of OPEs were calculated. Subsequently, the association between the urinary concentrations of OPE metabolites and the potential determinants of OPE exposure and health outcomes (e.g., obesity and serum lipids) was investigated. We found that bis(1-chloro-2-propyl) phosphate (BCIPP) and bis(2-chloroethyl) phosphate (BCEP) were the most prevalent urinary OPE metabolites, with median concentrations of 2.33 and 1.80 ng/mL, respectively; these concentrations were higher than those reported previously in other countries, such as the USA and China. Moreover, their parent compounds—tris(1-chloro-2-propyl) phosphate (TCIPP) and tris(2-chloroethyl) phosphate (TCEP)—exhibited EDIs of 126 and 94.8 ng/kg bw/day, respectively. Unlike the high detection rate of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) in other populations, its detection rate in this study was low (6.7%), suggesting regional differences in the exposure pattern of OPEs among countries. Furthermore, occupational characteristics, such as recent participation in firefighting activity, were identified as determinants of the urinary concentrations of OPE metabolites. Total OPE metabolites were inversely associated with body mass index and positively associated with high-density lipoprotein cholesterol. Overall, our findings demonstrate that Korean firefighters are highly exposed to several occupation-related OPEs. Further prospective studies will help elucidate the potential health implications of occupational exposure to OPEs among firefighters.
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•Eleven OPE metabolites were measured in urine samples of Korean firefighters.•BCIPP and BCEP were the most prevalent OPE metabolites.•Their concentrations were higher than those observed in the general population.•EDIs of TCIPP and TCEP were approximately 126 and 94.8 ng/kg bw/day, respectively.•Recent participation in firefighting activity was associated with urinary OPE metabolites.
Background and Aims: YG1699, a dual inhibitor of SGLT1 and SGLT2, recently showed greater glucose lowering than dapagliflozin in patients with type 1 diabetes. This study examined the potential ...mechanism of glucose reduction in rats.
Materials and methods: Sprague Dawley rats received either 0.3, 1, 3, or 10mg/kg of YG1699, or 3, 10mg/kg of LX4211 (sotagliflozin), or vehicle by oral gavage (n=8 per group). Fifteen minutes later, 2g/kg glucose was orally administered, and blood glucose was measured at 0, 20, 40, 60, 90, 120, and 150 mins. The area under the curve (AUC) for glucose over time was calculated. In the urinary glucose excretion (UGE) test, 24-hour urine samples were collected after vehicle, 1, 3, or 10mg/kg doses of YG1699, or 3mg/kg sotagliflozin (n=5 per group). Differences between groups were evaluated by ANOVA.
Results (See Table 1): 1, 3, and 10mg/kg doses of YG1699 and 3and 10mg/kg of sotagliflozin reduced glucose AUC and increased UGE compared to vehicle.
Conclusion: Significant reductions in post-prandial glucose with YG1699 and sotagliflozin are associated with increased UGE. Glucose AUC after 10mg/kg YG1699 was less than 50% of vehicle.
Disclosure
J.Li: None. R.W.Xu: Consultant; Youngene Therapeutics. J.He: None. P.Lapuerta: Board Member; 4M Therapeutics, Consultant; Youngene Therapeutics, ViaCyte, Inc., Encuragen, Capsida, Provention Bio, Inc., Decibel Therapeutics, Crinetics, Next Phase Therapeutics.
Changes in the expression of Na transport proteins were measured in the kidneys of mice with increased dietary K intake for 1 wk. The epithelial Na channel (ENaC) was upregulated, with enhanced ...expression of full-length and cleaved forms of α-ENaC and cleaved γ-ENaC. At the same time, the amount of the NaCl cotransporter NCC and its phosphorylated form decreased by ~50% and ~80%, respectively. The expression of the phosphorylated form of the Na-K-2Cl cotransporter NKCC2 also decreased, despite an increase in overall protein content. The effect was stronger in males (80%) than in females (40%). This implies that less Na
is reabsorbed in the thick ascending limb of Henle's loop and distal convoluted tubule along with Cl
, whereas more is reabsorbed in the aldosterone-sensitive distal nephron in exchange for secreted K
. The abundance of the proximal tubule Na/H exchanger NHE3 decreased by ~40%, with similar effects in males and females. Time-course studies indicated that NCC and NHE3 proteins decreased progressively over 7 days on a high-K diet. Expression of mRNA encoding these proteins increased, implying that the decreased protein levels resulted from decreased rates of synthesis or increased rates of degradation. The potential importance of changes in NHE3, NKCC2, and NCC in promoting K
excretion was assessed with a mathematical model. Simulations indicated that decreased NHE3 produced the largest effect. Regulation of proximal tubule Na
transport may play a significant role in achieving K homeostasis.
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