The change of gut microbiota-derived short-chain fatty acids in diabetic kidney disease.

BACKGROUND: Previous studies found the dysbiosis of intestinal microbiota in diabetic kidney disease (DKD), especially the decreased SCFA-producing bacteria. We aimed to investigate the concentration of the stool and serum short-chain fatty acids (SCFAs), gut microbiota-derived metabolites, in individuals with DKD and reveal the correlations between SCFAs and renal function. METHODS: A total of 30 participants with DKD, 30 participants with type 2 diabetes mellitus (DM), and 30 normal controls (NC) in HwaMei Hospital were recruited from 1/1/2018 to 12/31/2019. Participants with DKD were divided into low estimated glomerular filtration rate (eGFR)(eGFR<60ml/min, n=14) and high eGFR (eGFR≥60ml/min, n=16) subgroups. Stool and serum were measured for SCFAs with gas chromatograph-mass spectrometry. RESULTS: The DKD group showed markedly lower levels of fecal acetate, propionate, and butyrate versus NC (p<0.001, p<0.001, p=0.018, respectively) [1027.32(784.21-1357.90)]vs[2064.59(1561.82-2637.44)]µg/g,[929.53(493.65-1344.26)]vs[1684.57(1110.54-2324.69)]µg/g,[851.39(409.57-1611.65)] vs[1440.74(1004.15-2594.73)]µg/g, respectively, and the lowest fecal total SCFAs concentration among the groups. DKD group also had a lower serum caproate concentration than that with diabetes (p=0.020)[0.57(0.47-0.61)]vs[0.65(0.53-0.79)]µmol/L. In the univariate regression analysis, fecal and serum acetate correlated with eGFR (OR=1.013, p=0.072; OR=1.017, p=0.032). The correlation between serum total SCFAs and eGFR showed statistical significance (OR=1.019, p=0.024) unadjusted and a borderline significance (OR=1.024, p=0.063) when adjusted for Hb and LDL. The decrease in serum acetate and total SCFAs were found of borderline significant difference in both subgroups (p=0.055, p=0.050). CONCLUSION: This study provides evidence that in individuals with DKD, serum and fecal SCFAs levels (fecal level in particular) were lowered, and there was a negative correlation between SCFAs and renal function.

Social network analysis of virtual water trade among major countries in the world.

This study utilizes multi-region input-output model to calculate the virtual water trade among 19 major countries (the Group 20 countries, except the EU) from 2006 to 2015. Moreover, this paper uses network analysis method to study the characteristics of virtual water trade networks. Results show that: (1) the import and export of the virtual water trade among 19 major countries in 2015 increased in varying degrees. Among them, the growth rates of China's import and Russia's export were the highest. (2) The density(average value) and asymmetry(differences between import and export)of the virtual water trade network among the major countries in 2006-2015 increased throughout the whole industry and the three major industries. In comparison with the secondary and tertiary industries, the virtual water trade network formed by the primary industry is denser. (3) The Out-Degree(corresponding to export) and In-Degree(corresponding to import)of countries in the virtual water trade network of the whole industry increased in varying degrees in 2015. Major countries exhibited the largest export and import within the primary industry, except for Japan and South Korea. Therefore, in order to alleviate the contradiction between supply and demand of water resources in various countries, it is necessary to further strengthen the construction of transportation facilities and reduce the logistics cost of trade in industrial and agricultural products, especially the trade cost of agricultural products such as grain, so as to further expand the virtual water import and export trade to expand the import and export trade of the virtual water network further.

Full age spectrum equation versus CKD-EPI and MDRD equations to estimate glomerular filtration rate in adults with obstructive nephropathy.

OBJECTIVE: To compare the full age spectrum (FAS) equation with the Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in predicting glomerular filtration rate (GFR) in patients with obstructive nephropathy. METHODS: Adult patients with obstructive nephropathy who had undergone a GFR measurement using technetium-99m diethylenetriaminepentaacetic acid radioisotope renography were enrolled in the study. The measured GFR was taken as the reference value. Bias, precision and accuracy were compared between the three equations. Kappa test and the Bland-Altman method were used to evaluate the classification and the agreement. Receiver operating characteristic (ROC) curve analysis was used to describe the diagnostic accuracy of each equation. RESULTS: A total of 327 patients were enrolled. The P30 value for the FAS equation was 60.2% in the overall study cohort. The FAS equation had the highest diagnostic accuracy (ROCAUC = 0.87, 95% confidence interval [CI] 0.84, 0.91) compared with the MDRD equation (ROCAUC = 0.86, 95% CI 0.82, 0.89). The median bias of the FAS equation was significantly higher than that of the MDRD equation (8.7 versus 7.6 ml/min/1.73 m2, respectively). CONCLUSIONS: Despite the drawbacks associated with each equation, the FAS equation was probably closer to ideal to estimate GFR in patients with obstructive nephropathy.

Baseline Serum Magnesium Level and Its Variability in Maintenance Hemodialysis Patients: Associations with Mortality.

BACKGROUND/AIMS: The study aimed at investigating the impact of serum magnesium (Mg) baseline level and its variability on mortality in maintenance hemodialysis (MHD) patients. METHODS: Eligible patients receiving regular MHD at Ningbo No. 2 Hospital between January 2009 and August 2016 were enrolled and follow-ups were conducted afterwards until death or transplantation. General information, laboratory results, and outcomes of subjects were collected. The relationship between baseline serum Mg level, its coefficient of variation (CV), and all-cause mortality and cardiovascular disease mortality were assessed, respectively. Subjects were divided into groups in 2 manners: by serum Mg level (lower Mg group: serum Mg <1.00 mmol/L, higher Mg group: serum Mg ≥1.00 mmol/L) and by serum Mg CV (high variation group: CV ≥0.149 mmol/L, middle variation group: 0.114 mmol/L ≤ CV < 0.149 mmol/L, and low variation group: CV <0.114 mmol/L). RESULTS: 169 MHD patients were recruited in the study, with mean serum Mg 1.00 ± 0.18 mmol/L, average age 60.20 ± 15.64 years, and median dialysis duration 37.00 (18.30, 77.97) months. During the follow-up, 69 (40.83%) patients died, 24 (34.78%) of which died due to cardiovascular disease. Comparing the two groups, patients in the lower Mg group had a higher all-cause mortality (50.00 vs. 29.33%, p = 0.007). The multivariate Cox regression analysis suggested that lower Mg level was an independent factor for all-cause mortality as well as cardiovascular mortality (HR = 13.268, 95% CI 6.234-28.237, p < 0.001; HR = 12.702, 95% CI 3.737-43.174, p < 0.001, respectively). However, there were no significant statistical differences of all-cause and cardiovascular mortality among these three groups concerning Mg variation. And in the univariate and multivariate Cox regression analysis, serum magnesium CV was not the independent factor for all-cause mortality and cardiovascular mortality. CONCLUSIONS: The lower baseline serum magnesium level was associated with all-cause and cardiovascular mortality in MHD patients. However, the variability of magnesium level was not independently associated with the risk of death and further studies need to be conducted.

Long-term renal and overall survival of critically ill patients with acute renal injury who received continuous renal replacement therapy.

BACKGROUND: Acute kidney injury (AKI) is associated with the increased short-term mortality of critically ill patients on continuous renal replacement therapy (CRRT). The aim of this research was to evaluate the association of kidney function at discharge with the long-term renal and overall survival of critically ill patients with AKI who were on CRRT in an intensive care unit (ICU). METHODS: We retrospectively collected data for critically ill patients with AKI who were admitted to ICU on CRRT at a tertiary metropolitan hospital in China between 2008 and 2013. The patients were followed up to their death or to 30 September 2016 by telephone. RESULTS: A total of 403 patients were enrolled in this study. The 1-, 3- and 5-year patient survival rates were 64.3 ± 2.4, 55.8 ± 2.5 and 46.3 ± 2.7%, respectively. In multivariate analysis, age, sepsis, decreased renal perfusion (including volume contraction, congestive heart failure, hypotension and cardiac arrest), preexisting kidney disease, Apache II score, Saps II score, vasopressors and eGFR <45 mL/min/1.73 m2 at discharge were independent factors for worse long-term patient survival. And age, preexisting kidney disease, Apache II score, mechanical ventilation (MV) and eGFR <45 mL/min/1.73 m2 at discharge were also associated with worse renal survival. CONCLUSIONS: This study showed that impaired kidney function at discharge was shown to be an important risk factor affecting the long-term renal survival rates of critically ill patients with AKI. An eGFR <45 mL/min/1.73 m2 was an independent risk factor for decreased overall survival and renal survival.

Pre-conceptional intake of folic acid supplements is inversely associated with risk of preterm birth and small-for-gestational-age birth: a prospective cohort study.

Associations of folic acid supplementation with risk of preterm birth (PTB) and small-for-gestational-age (SGA) birth were unclear for the Chinese populations. The aim of the present study was to investigate the associations in a large Chinese prospective cohort study: the Jiaxing Birth Cohort. In the Jiaxing Birth Cohort, 240 954 pregnant women visited local clinics or hospitals within their first trimester in Southeast China during 1999-2012. Information on anthropometric parameters, folic acid supplementation and other maternal characteristics were collected by in-person interviews during their first visit. Pregnancy outcomes were recorded during the follow-up of these participants. Multinomial logistic regression was used to examine the association of folic acid supplementation with pregnancy outcomes. The prevalence of folic acid supplementation was 24·9% in the cohort. The prevalence of PTB and SGA birth was 3·48 and 9·2%, respectively. Pre-conceptional folic acid supplementation was associated with 8% lower risk of PTB (relative risk (RR) 0·92; 95% CI 0·85, 1·00; P=0·04) and 19% lower risk of SGA birth (RR 0·81; 95% CI 0·70, 0·95; P=0·008), compared with non-users. Higher frequency of pre-conceptional folic acid use was associated with lower risk of PTB (P trend=0·032) and SGA birth (P trend=0·046). No significant association between post-conceptional initiation of folic acid supplementation and either outcome was observed. In conclusion, the present study suggests an association between pre-conceptional, but not post-conceptional, folic acid supplementation and lower risk of PTB and SGA birth in the Jiaxing Birth Cohort. Further research in other cohorts of large sample size is needed to replicate these findings.

Implication of combined urinary biomarkers in early diagnosis of acute kidney injury following percutaneous coronary intervention.

BACKGROUND: Kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL) and interleukin 18 (IL-18) are three of the most promising biomarkers for the early detection of acute kidney injury. In the present study, to determine whether a combination of the three biomarkers enhances their predictive value, representing an ideal indicator for the early detection of Acute Kidney Injury (AKI) we examined 118 adults undergoing elective percutaneous coronary intervention (PCI). METHODS: We performed a single center, nested case-control study. Urinary KIM-1, NGAL and IL-18 were measured by enzyme-linked immunosorbent assay before and 6 h, 24 h, 48 h postcontrast. Serum creatinine was measured before and 24 h, 48 h postcontrast. RESULTS: 12 patients (10.1%) were identified with AKI. 30 patients were selected as controls, matched with cases at an attempted 2.5 : 1 ratio. Compared to the non-AKI group, urinary NGAL were significantly higher at all the time-points. Urinary KIM-1 and IL-18 levels were significantly higher at 24 h and 48 h postcontrast. In the AKI group, Urinary NGAL peaked at 6 h postcontrast, and then decreased. Both KIM-1 and IL-18 peaked at 24 hours postcontrast, remained markedly elevated up to 48 h. By applying area under the receiver operator characteristic curve, the combination of KIM-1, NGAL and IL-18 had the most powerful diagnostic power (AUC = 0.99, (95%CI: 0.90 - 1.00), p = 0.0001) for diagnosis of AKI at 24 h postcontrast, superior to that for single detection and serum creatinine. CONCLUSIONS: KIM-1, NGAL and IL-18 were increased in tandem after PCI. The combination of urinary biomarkers may allow for early detection of AKI following PCI, better than serum creatinine, and the individual biomarkers.