Effects of Fertilizer Application Intensity on Carbon Accumulation and Greenhouse Gas Emissions in Moso Bamboo Forest-Polygonatum cyrtonema Hua Agroforestry Systems.

Agroforestry management has immense potential in enhancing forest carbon sequestration and mitigating climate change. Yet the impact and response mechanism of compound fertilization rates on carbon sinks in agroforestry systems remain ambiguous. This study aims to elucidate the impact of different compound fertilizer rates on soil greenhouse gas (GHG) emissions, vegetation and soil organic carbon (SOC) sinks, and to illustrate the differences in agroforestry systems' carbon sinks through a one-year positioning test across 12 plots, applying different compound fertilizer application rates (0 (CK), 400 (A1), 800 (A2), and 1600 (A3) kg ha-1). The study demonstrated that, after fertilization, the total GHG emissions of A1 decreased by 4.41%, whereas A2 and A3 increased their total GHG emissions by 17.13% and 72.23%, respectively. The vegetation carbon sequestration of A1, A2, and A3 increased by 18.04%, 26.75%, and 28.65%, respectively, and the soil organic carbon sequestration rose by 32.57%, 42.27% and 43.29%, respectively. To sum up, in contrast with CK, the ecosystem carbon sequestration climbed by 54.41%, 51.67%, and 0.90%, respectively. Our study suggests that rational fertilization can improve the carbon sink of the ecosystem and effectively ameliorate climate change.

Incidence, risk factors and outcome of postoperative acute kidney injury in China.

BACKGROUND: Postoperative acute kidney injury (AKI) is a common condition after surgery, however, the available data about nationwide epidemiology of postoperative AKI in China from large and high-quality studies are limited. This study aimed to determine the incidence, risk factors and outcomes of postoperative AKI among patients undergoing surgery in China. METHODS: This was a large, multicentre, retrospective study performed in 16 tertiary medical centres in China. Adult patients (≥18 years of age) who underwent surgical procedures from 1 January 2013 to 31 December 2019 were included. Postoperative AKI was defined by the Kidney Disease: Improving Global Outcomes creatinine criteria. The associations of AKI and in-hospital outcomes were investigated using logistic regression models adjusted for potential confounders. RESULTS: Among 520 707 patients included in our study, 25 830 (5.0%) patients developed postoperative AKI. The incidence of postoperative AKI varied by surgery type, which was highest in cardiac (34.6%), urologic (8.7%) and general (4.2%) surgeries. A total of 89.2% of postoperative AKI cases were detected in the first 2 postoperative days. However, only 584 (2.3%) patients with postoperative AKI were diagnosed with AKI on discharge. Risk factors for postoperative AKI included older age, male sex, lower baseline kidney function, pre-surgery hospital stay ≤3 days or >7 days, hypertension, diabetes mellitus and use of proton pump inhibitors or diuretics. The risk of in-hospital death increased with the stage of AKI. In addition, patients with postoperative AKI had longer lengths of hospital stay (12 versus 19 days) and were more likely to require intensive care unit care (13.1% versus 45.0%) and renal replacement therapy (0.4% versus 7.7%). CONCLUSIONS: Postoperative AKI was common across surgery type in China, particularly for patients undergoing cardiac surgery. Implementation and evaluation of an alarm system is important for the battle against postoperative AKI.

Clinical outcomes of clip-assisted endoscopic cyanoacrylate injection versus conventional endoscopic cyanoacrylate injection in treating gastric varices with a gastrorenal shunt.

BACKGROUND AND STUDY AIMS: The optimal treatment for gastric varices (GVs) is a topic that remains definite for this study. This study compared the clinical outcomes of clip-assisted endoscopic cyanoacrylate injection (clip-ECI) to conventional endoscopic cyanoacrylate injection (con-ECI) for the treatment of GVs with a gastrorenal shunt. PATIENTS AND METHODS: Data were collected retrospectively in five medical centers from 2015 to 2020. The patients were treated with con-ECI (n = 126) or clip-ECI (n = 148). Clinical characteristics and procedural outcomes were compared. Patients were followed until death, liver transplantation or 6 months after the treatment. The primary outcome was rebleeding, and the secondary outcome was survival. RESULTS: There were no significant differences in age, sex, etiology, shunt diameter and Child-Pugh classification between the two groups. Fewer GVs obliteration sessions were required in the clip-ECI group than in the con-ECI group (p = 0.015). The cumulative 6-month rebleeding-free rates were 88.6% in the clip-ECI group and 73.7% in the con-ECI group (p = 0.002). The cumulative 6-month survival rates were 97.1% in the clip-ECI group and 94.8% in the con-ECI group (p = 0.378). CONCLUSIONS: Compared with con-ECI, clip-ECI appears more effective for the treatment of GVs with a gastrorenal shunt, which required less sessions and achieved a higher 6-month rebleeding-free rate.

Degradation reduces greenhouse gas emissions while weakening ecosystem carbon sequestration of Moso bamboo forests.

Moso bamboo (Phyllostachys heterocycla cv. Pubescens) is well known for its high capacity to sequester atmospheric carbon, which has a unique role to play in combating global warming. Many Moso bamboo forests are gradually degrading due to rising labor costs and falling prices for bamboo timber. However, the mechanisms of carbon sequestration of Moso bamboo forest ecosystems in response to degradation are unclear. In this study, a space-for-time substitution approach was used to select Moso bamboo forest plots with the same origin and similar stand types, but different years of degradation, and four degradation sequences, continuous management (CK), 2 years of degradation (D-I), 6 years of degradation (D-II) and 10 years of degradation (D-III). A total of 16 survey sample plots were established based on the local management history files. After a 12-month monitoring, the response characteristics of soil greenhouse gases (GHG) emissions, vegetation, and soil organic carbon sequestration in different degradation sequences were evaluated to reveal the differences in the ecosystem carbon sequestration. The results indicated that under D-I, D-II, and D-III, the global warming potential (GWP) of soil GHG emissions decreased by 10.84 %, 17.75 %, and 31.02 %, while soil organic carbon (SOC) sequestration increased by 2.82 %, 18.11 %, and 4.68 %, and vegetation carbon sequestration decreased by 17.30 %, 33.49 %, and 44.76 %, respectively. In conclusion, compared to CK, the ecosystem carbon sequestration was reduced by 13.79 %, 22.42 %, and 30.31 %, respectively. This suggests that degradation reduces soil GHG emissions but weakens the ecosystem carbon sequestration capability. Therefore, in the background of global warming and the strategic goal of carbon neutrality, restorative management of degraded Moso bamboo forests is critically needed to improve the carbon sequestration potential of the ecosystem.

Detecting Neonatal AKI by Serum Cystatin C.

SIGNIFICANCE STATEMENT: Serum creatinine is not a sensitive biomarker for neonatal AKI because it is confounded by maternal creatinine level, gestational age, and neonatal muscle mass. In this multicenter cohort study of 52,333 hospitalized Chinese neonates, the authors proposed serum cystatin C-related criteria (CyNA) for neonatal AKI. They found that cystatin C (Cys-C) is a robust and sensitive biomarker for identifying AKI in neonates who are at an elevated risk of in-hospital mortality and that CyNA detects 6.5 times as many cases as the modified Kidney Disease Improving Global Outcomes creatinine criteria. They also show that AKI can be detected using a single test of Cys-C. These findings suggest that CyNA shows promise as a powerful and easily applicable tool for detecting AKI in neonates. BACKGROUND: Serum creatinine is not a sensitive biomarker for AKI in neonates. A better biomarker-based criterion for neonatal AKI is needed. METHODS: In this large multicenter cohort study, we estimated the upper normal limit (UNL) and reference change value (RCV) of serum cystatin C (Cys-C) in neonates and proposed cystatin C-based criteria (CyNA) for detecting neonatal AKI using these values as the cutoffs. We assessed the association of CyNA-detected AKI with the risk of in-hospital death and compared CyNA performance versus performance of modified Kidney Disease Improving Global Outcomes (KDIGO) creatinine criteria. RESULTS: In this study of 52,333 hospitalized neonates in China, Cys-C level did not vary with gestational age and birth weight and remained relatively stable during the neonatal period. CyNA criteria define AKI by a serum Cys-C of ≥2.2 mg/L (UNL) or an increase in Cys-C of ≥25% (RCV) during the neonatal period. Among 45,839 neonates with measurements of both Cys-C and creatinine, 4513 (9.8%) had AKI detected by CyNA only, 373 (0.8%) by KDIGO only, and 381 (0.8%) by both criteria. Compared with neonates without AKI by both criteria, neonates with AKI detected by CyNA alone had an increased risk of in-hospital mortality (hazard ratio [HR], 2.86; 95% confidence interval [95% CI], 2.02 to 4.04). Neonates with AKI detected by both criteria had an even higher risk of in-hospital mortality (HR, 4.86; 95% CI, 2.84 to 8.29). CONCLUSIONS: Serum Cys-C is a robust and sensitive biomarker for detecting neonatal AKI. Compared with modified KDIGO creatinine criteria, CyNA is 6.5 times more sensitive in identifying neonates at elevated risk of in-hospital mortality.

Hepatocyte-derived exosomes deliver H2AFJ to hepatic stellate cells and promote liver fibrosis via the MAPK/STMN1 axis activation.

Hepatic stellate cells (HSCs) activate and acquire proliferative features in response to liver injury. However, mechanisms involved in the activation of fibrotic HSCs remain uncharacterized. This study aims at elaborating the mechanistic basis by which exosomal H2AFJ derived from hepatocytes might affect the activation of HSCs and liver fibrosis. Bioinformatics analysis based on transcriptomic RNA-seq data was used to screen out the downstream regulatory genes and pathways of H2AFJ. Mouse hepatocytes AML-12 cells were stimulated with CCl4 to mimic an in vitro microenvironment of liver fibrosis, from which exosomes were isolated. Next, HSCs were co-cultured with hepatocyte-derived exosomes followed by detection of HSC migration and invasion in the presence of manipulated H2AFJ and STMN1 expression and MAPK pathway inhibitor. It was found that H2AFJ was highly expressed in hepatocyte-derived exosomes after CCl4 stimulation. Hepatocyte-derived exosomal H2AFJ promoted HSC migration and invasion. H2AFJ upregulated c-jun-mediated STMN1 by activating the MAPK signaling pathway. Furthermore, in vivo experiments verified that silencing of H2AFJ attenuated liver fibrosis in mice, while restoration of STMN1 negated its effect. Collectively, hepatocyte-derived exosomal H2AFJ aggravated liver fibrosis by activating the MAPK/STMN1 signaling pathway. This study provides a potential therapeutic target for alleviating liver fibrosis.

Use of Histologic Parameters to Predict Glomerular Disease Progression: Findings From the China Kidney Biopsy Cohort Study.

RATIONALE & OBJECTIVE: Challenges in achieving valid risk prediction and stratification impede treatment decisions and clinical research design for patients with glomerular diseases. This study evaluated whether chronic histologic changes, when complementing other clinical data, improved the prediction of disease outcomes across a diverse group of glomerular diseases. STUDY DESIGN: Multicenter retrospective cohort study. SETTING & PARTICIPANTS: 4,982 patients with biopsy-proven glomerular disease who underwent native biopsy at 8 tertiary care hospitals across China in 2004-2020. NEW PREDICTORS & ESTABLISHED PREDICTORS: Chronicity scores depicted as 4 categories of histological chronic change, as well as baseline clinical and demographic variables. OUTCOME: Progression of glomerular disease defined as a composite of kidney failure or a ≥40% decrease in estimated glomerular filtration rate from the measurement at the time of biopsy. ANALYTICAL APPROACH: Multivariable Cox proportional hazard models. The performance of predictive models was evaluated by C statistic, time-dependent area under the receiver operating characteristic curve (AUROC), net reclassification index, integrated discrimination index, and calibration plots. RESULTS: The derivation and validation cohorts included 3,488 and 1,494 patients, respectively. During a median of 31 months of follow-up, a total of 444 (8.9%) patients had disease progression in the 2 cohorts. For prediction of the 2-year risk of disease progression, the AUROC of the model combining chronicity score and the Kidney Failure Risk Equation (KFRE) in the validation cohort was 0.76 (95% CI, 0.65-0.87); in comparison with the KFRE model (AUROC, 0.68 [95% CI, 0.56-0.79]), the combined model was significantly better (P = 0.04). The combined model also had a better fit, with a lower Akaike information criterion and a significant improvement in reclassification as assessed by the integrated discrimination improvements and net reclassification improvements. Similar improvements in predictive performance were observed in subgroup and sensitivity analyses. LIMITATIONS: Selection bias, relatively short follow-up, lack of external validation. CONCLUSIONS: Adding histologic chronicity scores to the KFRE model improved the prediction of kidney disease progression at the time of kidney biopsy in patients with glomerular diseases. PLAIN-LANGUAGE SUMMARY: Risk prediction and stratification remain big challenges for treatment decisions and clinical research design for patients with glomerular diseases. The extent of chronic changes is an important component of kidney biopsy evaluations in glomerular disease. In this large multicenter cohort including 4,982 Chinese adults undergoing native kidney biopsy, we evaluated whether histologic chronicity scores, when added to clinical data, could improve the prediction of disease prognosis for a diverse set of glomerular diseases. We observed that adding histologic chronicity scores to the kidney failure risk equation improved the prediction of kidney disease progression at the time of kidney biopsy in patients with glomerular diseases.

A novel risk factor of contrast associated acute kidney injury in patients after enhanced computed tomography: a retrospective study.

Background: Contrast associated acute kidney injury (CA-AKI) is a major cause of acute renal failure and the incidence of CA-AKI is still high in recent years. Risk stratification is traditionally based on glomerular filtration rate(GFR). Hence, the aim of this study was to explore the novel risk factors for CA-AKI after enhanced computed tomography (CT). Methods: A retrospective cohort study was conducted in 632 in-hospital patients undergoing enhanced CT. The patients were divided into CA-AKI and no-CA-AKI groups. For comparative analyses, we applied one-to-four cohorts of those two groups using propensity score-matching methods addressing the imbalances of age, gender, weight, and smoking. The baseline clinical and biochemical data were compared. Logistic regression analysis was employed to investigate the CA-AKI risk factors. The receiver operating characteristic (ROC) curve was adopted to test the value of RDW in predicting CA-AKI after enhanced CT. Results: 25 (3.96%) patients suffered from CA-AKI. Those subjects who developed CA-AKI had advanced age, severer renal functional injury, lower albumin, higher baseline RDW, neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) than those without CA-AKI. It also exhibited more severe anemia including decreased hemoglobin and red blood cell count (all p < 0.05). The baseline RDW, albumin and PLR between the two groups were statistically significant different after PSM. Binary logistic regression analysis showed that baseline RDW, albumin and eGFR were correlated with CA-AKI after contrast-enhanced CT examination. The RDW exhibited moderated discrimination ability for predicting CA-AKI beyond eGFR, with an AUC of 0.803 (95% CI [0.702-0.90]) vs 0.765 (95% CI [0.70-0.83]). Conclusion: Increased baseline RDW and decreased eGFR are risk factors for CA-AKI after enhanced CT. RDW exhibited good predictive value and can be used as an early warning marker for patients suffering from CA-AKI after enhanced CT.

Effects of Electromagnetic Fields on the Microstructure of Laser Cladding.

The fast heating and quenching of laser cladding increase the internal stresses in the cladding layer. Moreover, the quick condensation of the molten pool leads to an uneven distribution of the internal elements and coarse grains of the structure. To address the above defects and increase the molding quality of laser cladding, an electromagnetic field was introduced into the laser cladding technique, and the effects of the external assisted electromagnetic field on the mixed metal fluid in the molten pool were explored. On this basis, the action of the electromagnetic field on the flow states of the molten pool was further analyzed. The results demonstrate that after introducing electromagnetic assistance, the material flow in the molten pool accelerated as a response to the periodic changes in electromagnetic forces and the influences of the electromagnetic field on crystallization, thus refining the grains and improving the grain distribution uniformity in the cladding layer. The dendritic crystals in the cladding layer decreased, while the isometric crystals and the cellular-like dendrites increased. The element distribution in the cladding layer increased in uniformity. Additionally, this method can decrease the dilution rate of the cladding layer and improve its overall hardness. A laser-cladding test of the Ni-based powder was carried out on the AISI 1045 steel surface under the coaxial powder-feeding mode. Moreover, the influences of the electromagnetic field on the microstructure of the laser-cladding layer were compared, and the causes of the changes were disclosed.

Pocket-creation method versus conventional method of endoscopic submucosal dissection for superficial colorectal neoplasms: a meta-analysis.

BACKGROUND AND AIMS: The pocket-creation method (PCM) is a newly developed strategy for colorectal endoscopic submucosal dissection (ESD). However, its superiority over the conventional method (CM) has not been established. The aim of this meta-analysis was to evaluate the efficacy and safety of PCM-ESD compared with CM-ESD for superficial colorectal neoplasms (SCNs). METHODS: Literature searches were conducted using the Pubmed, Embase, and Cochrane Library databases, and a meta-analysis was performed. The primary outcome was the R0 resection rate, and the secondary outcomes were the en bloc resection rate, dissection speed, procedure time, and adverse event rate. RESULTS: Five studies (2 randomized controlled trials and 3 retrospective studies) with 1481 patients were included in our meta-analysis. The pooled analysis showed that PCM-ESD achieved a higher R0 resection rate (93.5% vs 78.1%; odds ratio [OR], 3.4; 95% confidence interval [CI], 1.3-8.9; I2 = 58%), a higher en bloc resection rate (99.8% vs 92.8%; OR, 9.9; 95% CI, 2.7-36.2; I2 = 0), a shorter procedure time (minutes) (mean difference [MD], -11.5; 95% CI, -19.9 to -3.1; I2 = 72%), a faster dissection speed (mm2/min) (MD, 3.6; 95% CI, 2.8-4.5; I2 = 0), and a lower overall adverse event rate (4.4% vs 6.6%; OR, 0.6; 95% CI, 0.3-1.0; I2 = 0) compared with CM-ESD. CONCLUSIONS: This meta-analysis showed that PCM-ESD improves the efficacy and safety compared with CM-ESD for superficial colorectal neoplasms.

Silicate fertilizer application reduces soil greenhouse gas emissions in a Moso bamboo forest.

Silicate fertilizer application in croplands is effective in mitigating soil methane (CH4) emissions and increasing rice yield. However, the effects of silicate fertilizer on soil greenhouse gas (GHG) emissions in Moso bamboo forests, and the underlying mechanisms are poorly understood. In the present study, a two-year field experiment was conducted to investigate the effect of silicate fertilizer rates (0 (CK), 0.225 and 1.125 Mg ha-1) on soil GHG emissions in a Moso bamboo forest. The results showed that silicate fertilizer application significantly reduced soil CO2 and N2O emissions, and increased soil CH4 uptakes. Compared to the CK treatments, the cumulative soil CO2 emission fluxes decreased by 29.6% and 32.5%, and the cumulative soil N2O emission fluxes decrease by 41.9% and 48.3%, the CH4 uptake fluxes increased by 13.5% and 32.4% in the 0.225 and 1.125 Mg ha-1 treatments, respectively. The soil GHG emissions were significantly positively related to soil temperature (P < 0.05), but negatively related to soil moisture; however, this relationship was not observed between CH4 uptake fluxes and moisture in CK treatment. Soil CO2 emission and CH4 uptake were significantly positively related with water-soluble organic C (WSOC) and microbial biomass C (MBC) concentrations in all treatments (P < 0.05). Soil N2O emissions were significantly positively related to MBC, NH4+-N, NO3--N, and microbial biomass N (MBN) concentrations in all treatments (P < 0.05), but not with WSOC concentration. Structural equation modeling showed that application of silicate fertilizer directly reduced soil GHG emission by decreasing the labile C and N pools, and indirectly by influencing the soil physicochemical properties. Our findings suggest that silicate fertilizer can be an effective tool in combatting climate change by reducing soil GHG emissions in Moso bamboo forests.

Long noncoding RNA LINC-PINT is inhibited in gastric cancer and predicts poor survival.

Long noncoding RNA (lncRNA) LINC-PINT expression is inhibited in many types of cancer cells, suggesting its role as a tumor suppressor. However, the functionality of LINC-PINT in gastric cancer and the clinical values are unknown. In the present study, we found that lncRNA LINC-PINT was downregulated, while microRNA-21 (miR-21) was upregulated in tumor tissues than in adjacent healthy tissues of gastric cancer patients. A significant and inverse correlation between expression levels of lncRNA LINC-PINT and miR-21 was found in both tumor tissues and adjacent healthy tissues. The low expression level of LINC-PINT and high expression level of the miR-21 tumor were correlated with poor prognosis. LINC-PINT overexpression casued miR-21 inhibition in cells of human gastric cancer cell lines, while miR-21 overexpression did not alter LINC-PINT expression. LINC-PINT overexpression led to inhibited, while miR-21 overexpression led to promoted proliferation, migration, and invasion of gastric cancer cells. Effects of LINC-PINT overexpression on cellular behaviors of gastric cancer cells were attenuated by miR-21 overexpression. Therefore, LINC-PINT may participate in gastric cancer through the crosstalk with miR-21.

Endoscopic mucosal resection with suction vs. endoscopic submucosal dissection for small rectal neuroendocrine tumors: a meta-analysis.

OBJECTIVE: There are no guidelines or consensus on the optimal treatment measures for small rectal neuroendocrine tumors (NETs) at present. This meta-analysis was conducted to compare the efficacy and safety of endoscopic mucosal resection (EMR) with suction and endoscopic submucosal dissection (ESD) for the small rectal NETs. METHODS: The literature searches were conducted using Pubmed and Embase databases, and then a meta-analysis was performed. The primary outcome was complete resection rate, and the secondary outcomes were complication rate, procedure time, and recurrence rate. RESULTS: Fourteen studies with 823 patients were included in our meta-analysis. The overall complete resection rates in EMR with suction and ESD procedure were 93.65% (472/504) and 84.08% (243/289), respectively. The pooled analysis showed that EMR with suction could achieve a higher complete resection rate than ESD with significance (OR: 4.08, 95% CI: 2.42-6.88, p < .00001) when the outlier study was excluded, and procedure time was significantly shorter in the EMR with suction group than in the ESD group (SMD: -1.59, 95% CI: -2.27 to -0.90, p < .00001). Moreover, there was no significant difference in overall complication rate (OR: 0.56, 95% CI: 0.28-1.14, p = .11) and overall recurrence rate (OR: 0.76, 95% CI: 0.11-5.07, I2=48%) between EMR with suction and ESD group. CONCLUSIONS: The present meta-analysis mostly based on retrospective studies show that EMR with suction is superior to ESD for small rectal NETs (≤10 mm) with higher complete resection rate, shorter procedure time, and similar overall complication rate and recurrence.

[Correlation of serum androgen levels with lipid metabolism in middle-aged and elderly men in Zunyi, Guizhou].

OBJECTIVE: To investigate the relationship of the levels of serum androgens with lipid metabolism in middle-aged and elderly men in Zunyi, Guizhou. METHODS: Using the stratified cluster sampling method, we conducted a questionnaire investigation and physical examinations among 437 men in Zunyi City. We divided the subjects into a middle-aged (40－64 ï¼»53.20 ± 7.41ï¼½ years, n = 269) and an elderly group (=≥65 ï¼»70.63 ± 4.66ï¼½ years, n = 168) and collected fasting elbow venous blood samples from them for measuring the levels of total testosterone (TT), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), total cholesterol (TCH), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), calculated free testosterone (cFT), free testosterone index (FTI), and testosterone secretion index (TSI). RESULTS: Compared with the elderly group, the middle-aged males showed significantly lower SHBG, LH, HDL and LDL, and higher cFT, FTI, TSI, TG and TCH (all P < 0.05). TT and SHBG were negatively correlated with TG, TCH, HDL and LDL, while cFT was positively correlated with TCH, and so was FTI with TG, TCH with LDL, and TSI with TCH, HDL and LDL (all P < 0.05), but LH was negatively correlated with TG, TCH and LDL (all P < 0.05). Multivariate linear regression analysis showed that TT and SHBG were negatively correlated with TG, TCH, HDL and LDL, and so was LH with TCH, HDL and LDL (all P < 0.05). CONCLUSIONS: In the middle-aged and elderly men in Zunyi, low concentrations of TT, SHBG and LH were associated with the increased risk of high-TCH and -LDL dyslipidemia, low concentrations of TT and SHBG with that of high-TG dyslipidemia, while high concentrations of TT, SHBG and LH with that of low-HDL dyslipidemia.

[Vasectomy has no obvious longterm influence on the levels of serum androgens in aging males].

OBJECTIVE: To explore the longterm influence of vasectomy on the levels of serum androgens in aging males. METHODS: Using stratified random sampling, we conducted a questionnaire survey and physical examinations among 437 adult males aged ≥40 years, 232 with and 205 without the history of vasectomy. In addition, we measured the levels of serum total testosterone (TT), sexhormone binding globulin (SHBG), calculated free testosterone (cFT), testosterone secreting index (TSI), free testosterone index (FTI), and luteinizing hormone (LH). RESULTS: Compared with the nonvasectomy group, the vasectomy group showed significantly increased levels of serum TT (ï¼»16.01±5.41ï¼½ vs ï¼»17.39±6.57ï¼½ nmol/L), SHBG (ï¼»58.91±36.89ï¼½ vs ï¼»70.28±40.90ï¼½ nmol/L), and LH (ï¼»8.86±6.49ï¼½ vs ï¼»10.85±11.73ï¼½ IU/L) (all P< 0.05) and a decreased level of FTI (0.33±0.15 vs 0.30±0.12, P< 0.05). There were no statistically significant differences between the nonvasectomy and vasectomy groups in cFT (ï¼»0.24±0.07ï¼½ vs ï¼»0.23±0.09ï¼½ nmol/L) or TSI (ï¼»2.42±1.34ï¼½ vs ï¼»2.46±1.51ï¼½ nmol/IU) (both P>0.05), nor after adjustment for relevant factors in TT (ß: 1.015, 95% CI: －0.180－2.210), SHBG (ß: 5.118, 95% CI: －2.069－12.305), cFT (ß: 0.003, 95% CI: －0.011－0.018), FTI (ß: －0.012, 95% CI: －0.035－0.011), TSI (ß: 0.138, 95% CI: －0.131－0.407), and LH (ß: 1.011, 95% CI: －0.811－2.834) (all P>0.05). CONCLUSIONS: Vasectomy has no obvious longterm influence on the levels of serum androgens in aging males.

Reference Ranges and Association of Age and Lifestyle Characteristics with Testosterone, Sex Hormone Binding Globulin, and Luteinizing Hormone among 1166 Western Chinese Men.

Decreased total testosterone (TT) is the recommended metric to identify age-related hypogonadism. However, average TT and the extent to which it varies by age, can vary substantially among different populations. Population-specific reference ranges are needed to understand normal versus abnormal TT levels. Therefore, the goal for this study was to describe androgen concentrations and their correlates among Western Chinese men. We completed a population-based, cross-sectional study including 227 young adults (YA) (20-39 years) and 939 older adults (OA) (40-89 years). We measured TT, sex-hormone binding globulin (SHBG), luteinizing hormone (LH), testosterone secreting index (TSI), and calculated free testosterone (cFT). Reference ranges for this population were determined using average YA concentrations. Multivariable regression models were used to predict hormone concentrations adjusting for age, waist-to-height ratio (WHR), marital status, education, occupation, smoking, alcohol, blood glucose, and blood pressure. Among OA, 3.8% had low TT, 15.2% had low cFT, 26.3% had low TSI, 21.6% had high SHBG, and 6.1% had high LH. Average cFT was significantly lower in OA (0.30 nmol/L; standard deviation (SD): 0.09) versus YA (0.37; SD: 0.11) but TT was not different in OA (16.82 nmol/L; SD: 4.80) versus YA (16.88; SD: 5.29). In adjusted models increasing age was significantly associated with increased SHBG or LH, and decreased cFT or TSI; however, TT was not significantly associated with age (ß = 0.02 nmol/L; 95% confidence interval (CI): -0.01, 0.04). Higher WHR was associated with significantly decreased TT, SHBG, TSI, and LH. The only variable significantly related to cFT was age (ß = -0.0033; 95% CI:-0.0037, -0.0028); suggesting that cFT measurements would not be confounded by other lifestyle factors. In conclusion, cFT, but not TT, varies with age in this population, suggesting cFT may be a better potential marker for age-related androgen deficiency than TT among Western Chinese men.