Alteration of Plasma Indoles in Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies in reproductive-aged women. The occurrence of PCOS was reported to be associated with the alteration of gut microbiota. Microbiota-derived indoles may possibly play a key role in glycemic control. The purpose of this work is to reveal the alteration of plasma indoles in PCOS patients and to investigate the correlation between indoles levels and glucose metabolism. Sixty-five patients with PCOS and twenty-eight age-matched women were enrolled in this work. The concentrations of plasma indoles, including indoxyl sulfate (IS), indole-3-acetic acid (IAA), indole-3-propionate (IPA), indole (IND), and 3-methylindole (3-MI), were measured by HPLC with the fluorescence detection. The plasma levels of IS, IAA, and IND were significantly elevated in patients with PCOS compared to those in the control group (p < 0.05). Furthermore, the plasma levels of IS, IAA, and IND were positively correlated with fasting glucose, fasting insulin, and the homeostatic model of insulin resistance index (HOMA-IR) (p < 0.05). Besides, the 3-MI level in the plasma was positively correlated with the fasting glucose level, whereas plasma levels of IS, IAA, IND, and 3-MI were negatively correlated with glucagon-like peptide 1 (p < 0.05). Moreover, IS and IND were considered to be risk factors for PCOS after age, BMI, T, LH, and HOMA-IR adjustment. The area under the receiver-operating characteristic curve of the combined index of five indoles was 0.867 for PCOS diagnosis. Additionally, plasma indoles altered in PCOS, which was closely associated with the glucose metabolism.

Corticotropin Stimulation in Adrenal Venous Sampling for Patients With Primary Aldosteronism: The ADOPA Randomized Clinical Trial.

Importance: Adrenal venous sampling (AVS) is usually recommended to distinguish between unilateral and bilateral primary aldosteronism (PA) before definitive surgical or medical treatment is offered. Whether a treatment decision based on AVS with or without corticotropin (ACTH) stimulation leads to different biochemical and clinical remission rates in patients with PA remains unclear. Objective: To evaluate whether treatment decisions based on AVS with or without ACTH stimulation lead to different biochemical and clinical remission rates in patients with PA. Design, Setting, and Participants: This randomized clinical trial (RCT) was conducted at a tertiary hospital in China from July 8, 2020, to February 20, 2023, among patients with PA aged 18 to 70 years. Patients were followed up for 12 months after the initiation of treatment. An intention-to-diagnose analysis was conducted. Interventions: Patients were randomly assigned to undergo either ACTH-stimulated or non-ACTH-stimulated AVS. Main Outcomes and Measures: The primary end point was the proportion of patients with complete biochemical remission after 12 months of follow-up. Secondary outcomes included the proportion of patients who achieved complete clinical remission after 12 months of follow-up, dosages of antihypertensive agents, rate of successful bilateral AVS, and adverse events. Results: Of 228 patients with PA, 115 were randomized to the non-ACTH-stimulated group (median age, 50.0 years [IQR, 41.0-57.0 years]; 70 males [60.9%]) and 113 to the ACTH-stimulated group (median age, 50.0 years [IQR, 43.5-56.5 years]; 63 males [55.8%]). A total of 68 patients (59.1%) underwent adrenalectomy in the non-ACTH group and 65 (57.5%) in the ACTH group. There was no significant difference in the proportion of patients with complete biochemical remission who were managed on the basis of AVS with vs without ACTH stimulation (with: 56 of 113 [49.6%]; without: 59 of 115 [51.3%]; P = .79). There also was no significant difference in the proportion of patients who achieved complete clinical remission between the non-ACTH and ACTH groups (26 of 115 [22.6%] and 31 of 113 [27.4%], respectively; P = .40). The intensity of therapy with antihypertensives, successful catheterization of bilateral adrenal veins, and incidence of adverse events did not significantly differ between the non-ACTH and ACTH groups. Conclusions and Relevance: In this RCT, treatment of PA on the basis of non-ACTH-stimulated or ACTH-stimulated AVS did not lead to significant differences in clinical outcomes for the patients. These results suggest that ACTH stimulation during AVS may not have clinical benefit, at least in the Chinese population. Trial Registration: ClinicalTrials.gov Identifier: NCT04461535.

Dual-Template Magnetic Molecularly Imprinted Polymer for Simultaneous Determination of Spot Urine Metanephrines and 3-Methoxytyramine for the Diagnosis of Pheochromocytomas and Paragangliomas.

A novel dual-template magnetic molecularly imprinted polymer (MMIP) was synthesized to extract normetanephrine (NMN), metanephrine (MN) and 3-methoxytyramine (3-MT) from spot urine samples. As the adsorbent of dispersive solid-phase extraction (d-SPE), the MMIP was prepared using dopamine and MN as dual templates, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinking reagent and magnetic nanoparticles as the magnetic core. NMN, MN, 3-MT and creatinine (Cr) in spot urine samples were selectively enriched by d-SPE and detected by HPLC-fluorescence detection/ultraviolet detection. The peak area (A) ratios of NMN, MN and 3-MT to Cr were used for the diagnosis of pheochromocytomas and paragangliomas (PPGLs). The results showed that the adsorption efficiencies of MMIP for target analytes were all higher than 89.0%, and the coefficient variation precisions of intra-assay and inter-assay for the analytes were within 4.9% and 6.3%, respectively. The recoveries of the analytes were from 93.2% to 112.8%. The MMIP was still functional within 14 days and could be reused at least seven times. The d-SPE and recommended solid-phase extraction (SPE) were both used to pretreat spot urine samples from 18 PPGLs patients and 22 healthy controls. The correlation coefficients of ANMN/ACr and AMN/ACr between d-SPE and SPE were both higher than 0.95. In addition, the areas under the receiver operator curves for spot urine ANMN/ACr, AMN/ACr and plasma free NMN and MN were 0.975, 0.773 and 0.990, 0.821, respectively, indicating the two methods had the similar performances. The d-SPE method took only 20 min, which was effective in clinical application.

Circulating exosome-like vesicles of humans with nondiabetic obesity impaired islet ß-cell proliferation, which was associated with decreased Omentin-1 protein cargo.

The regulation of ß-cell mass in the status of nondiabetic obesity remains not well understood. We aimed to investigate the role of circulating exosome-like vesicles (ELVs) isolated from humans with simple obesity in the regulation of islet ß-cell mass. Between June 2017 and July 2019, 81 subjects with simple obesity and 102 healthy volunteers with normal weight were recruited. ELVs were isolated by ultra-centrifugation. The proliferations of ß-cells and islets were measured by 5-ethynl-2'-deoxyuridine (EdU). Protein components in ELVs were identified by Quantitative Proteomic Analysis and verified by Western blot and ELISA. The role of specific exosomal protein was analyzed by gain-of-function approach in ELVs released by 3T3-L1 preadipocytes. Circulating ELVs from subjects with simple obesity inhibited ß-cell proliferation in vitro without affecting its apoptosis, secretion, and inflammation. The protein levels of Rictor and Omentin-1 were downregulated in circulating ELVs from subjects with simple obesity and associated with the obesity-linked pathologic conditions. The ELV-carried Omentin-1 and Omentin-1 protein per se were validated to increase ß-cell proliferation and activate Akt signaling pathway. Moreover, Omentin-1 in ELVs was downregulated by insulin. The circulating ELVs may act as a negative regulator for ß-cell mass in nondiabetic obesity through inhibiting ß-cell proliferation. This effect was associated with downregulated Omentin-1 protein in ELVs. This newly identified ELV-carried protein could be a mediator linking insulin resistance to impaired ß-cell proliferation and a new potential target for increasing ß-cell mass in obesity and T2DM.

Effect of Addition of WZB117 as an Inhibitor of Glucose Transporter 1 for Venous Blood Glucose Determination.

OBJECTIVE: Sodium fluoride (NaF) has been applied to inhibit glycolysis in venous specimens for decades. However, it has had little effect on the rate of glycolysis in the first 1 to 2 hours, resulting in a decrease of glucose, so a more efficient method is needed. Recently, we discovered that WZB117, a specific Glut1 inhibitor, restricts glycolysis by inhibiting the passive sugar transport of human red blood cells and cancer cells. The purpose of this study was to evaluate the results of intravenous blood glucose determination after the addition of WZB117. METHODS: Venous specimens from 40 pairs of healthy volunteers were collected for several days and placed in tubes containing NaF plus EDTA-disodium (Na2) without WZB117 (the A group); citric acid, trisodium citrate, and EDTA-Na2 without WZB117 (B group); and NaF plus EDTA-Na2 with WZB117 (C group). The glucose concentration was measured after venipuncture and compared with test tubes treated for 1 hour, 2 hours, and 3 hours before centrifugation. Glucose level was determined by the hexokinase method. The paired t-test was used to examine differences in glucose values at baseline and at different time points. The number of misdiagnoses and the misdiagnosis rate were calculated at 2 diagnostic stages: high risk of diabetes (glucose level of 6.1 mmol/L) and diagnosis of diabetes (glucose level of 7.0 mmol/L). RESULTS: Glucose levels decreased by 1.0% at 1 hour and by 2.1% at 3 hours in the C group tubes and simultaneously decreased by 1.7% at 1 hour and by 2.5% at 3 hours in the B group tubes. In contrast, glucose levels decreased by 4.1% at 1 hour and by 6.3% at 3 hours in the A group tubes. There was a statistically significant difference in glucose levels measured in the A group tubes and B group tubes at 1 hour, 2 hours, and 3 hours. The misdiagnosis rate of clinical diagnosis in diabetes was highest in the A group tubes (7.0‰ at 1 hour, 0.1‰ at 3 hours at 7.0 mmol/L point; 14.6‰ at 1 hour, 0.4‰ at 3 hours at 6.1 mmol/L point) and lowest in the C group tubes (2.95‰ at 1 hour, 0‰ at 3 hours at 7.0 mmol/L point; 4.8‰ at 1 hour, 0.1‰ at 3 hours at 6.1 mmol/L point). CONCLUSION: The tube addition of WZB117 is more suitable for minimizing glycolysis and has no effect on glucose levels even if specimens are left uncentrifuged for up to 3 hours.

A sensitive electrochemical method for indole based on the signal amplification strategy by gold/iron-oxide composite nanoparticles.

Indole is a major metabolite of tryptophan, which plays an important role in the intestinal microecological balance and human physiological activities. The determination of indole becomes important for its researches. So, it is urgent to establish a sensitive and cost-effective method for indole detection. Herein, a sensitive electrochemical method was constructed to determine the concentration of indole using screen-printed carbon electrode (SPCE) with the signal amplification strategy by gold/iron-oxide composite nanoparticles (Au/Fe3O4). Au/Fe3O4 nanoparticles were successfully synthesized under the irradiation by high-energy electron beams. 4-aminothiophenol (4-ATP) was connected to Au/Fe3O4 via Au-S bond. And then NaNO2 reacted with 4-ATP to form the azo bond, which could form the final product of Au/Fe3O4@ATP-azo-indole by the coupling reaction. Thus, the concentration of indole was detected by the electrochemical signal produced by Au/Fe3O4@ATP-azo-indole indirectly. The detection sensitivity was greatly improved by the large specific surface area provided by Au/Fe3O4 after the modification. The linear range of indole was from 0.50 to 120.00 µg L-1 and the limit of detection (LOD) was as low as 0.10 µg L-1 (S/N = 3). Furthermore, the developed method exhibited acceptable intra-day and inter-day precisions with the coefficient of variations (CV) less than 4.9% and 8.2%, respectively. And the recoveries were from 97.2% to 105.4%. An innovative, sensitive, cost-effective method was established for indole determination in human plasma matrix in this manuscript, which provides a promising way for indole detection in conventional laboratories.

Detection of spot urinary free metanephrines and 3-methoxytyramine with internal reference correction for the diagnosis of pheochromocytomas and paragangliomas.

Detection of normetanephrine (NMN), metanephrine (MN) and 3-methoxytyramine (3-MT) could be used to diagnose pheochromocytomas and paragangliomas (PPGLs). The accuracy for the diagnosis of PPGLs is only 6% by virtue of the classic symptom triad. In addition, false-positive results were found using plasma free MNs as biomarkers. Spot urinary free metanephrines (MNs) presented high specificity for PPGLs diagnosis in our previous work by HPLC with the electrochemical detection. Whereas, MNs and creatinine (Cr) need to be detected separately. A simple and specific method was urgently needed for the diagnosis of PPGLs. Here, we established a new HPLC method for spot urinary free MNs and 3-MT by the fluorescence detection and Cr by the ultraviolet detection simultaneously. It was worth mentioning that Cr for the virtue of being fairly constant in a given subject was used as an internal reference correction to eliminate the effect of spot urine volume for the diagnosis of PPGLs. Thirty-seven patients with PPGLs and 164 control subjects were detected by the established method and the peak area ratios of MNs and 3-MT to Cr were used innovatively for the diagnosis of PPGLs. The results showed acceptable precisions and recoveries. The sensitivities of the method were 94.6%, 91.9% and 86.5% and the specificities were 96.3%, 93.9% and 82.3%, respectively by the peak area of NMN/Cr, MN/Cr and 3-MT/Cr for the diagnosis. The established method provides a promising way for simple, rapid and accurate diagnosis of PPGLs.

Early-onset type 2 diabetes: A high-risk factor for proliferative diabetic retinopathy (PDR) in patients with microalbuminuria.

We aim to explore the relationship between early-onset diabetes and proliferative diabetic retinopathy (PDR) in type 2 diabetes mellitus (T2DM) patients with microalbuminuria.A total of 461 T2DM patients with microalbuminuria were enrolled. Subjects were defined as early-onset or late-onset based on the age at which they were diagnosed with diabetes (<40 and ≥40 years, respectively). Medical history, anthropometry, and laboratory indicators were documented. PDR was defined as the presence of any of the following changes on fundus photography: neovascularization, vitreous hemorrhage, or preretinal hemorrhage.The prevalence of PDR was 6-fold higher in patients with early-onset than late-onset T2DM [(6.1% vs 1.0%), P = .004]. Univariate correlation analysis showed that early-onset diabetes, use of oral hypoglycemic drugs, and insulin therapy were risk factors for PDR. In multivariate logistic analysis, patients with early-onset diabetes exhibited a 7.00-fold [(95% confidence interval 1.40-38.26), P = .019] higher risk of PDR than subjects with late-onset diabetes after adjusting for sex; T2DM duration; systolic blood pressure; total triglyceride; glycated hemoglobin; insulin therapy; and the use of oral hypoglycemic drugs, antihypertensive drugs, and lipid-lowering drugs.In T2DM patients with microalbuminuria, early-onset diabetes is an independent risk factor for the development of PDR.

TOTAL BODY ADIPOSITY, TRIGLYCERIDES, AND LEG FAT ARE INDEPENDENT RISK FACTORS FOR DIABETIC PERIPHERAL NEUROPATHY IN CHINESE PATIENTS WITH TYPE 2 DIABETES MELLITUS.

OBJECTIVE: To evaluate the risk factors associated with diabetic peripheral neuropathy (DPN) in Chinese patients with type 2 diabetes mellitus (T2DM). METHODS: Between January 2014 and December 2017, 107 participants who had obesity with T2DM and 349 participants who had normal weight with T2DM, matched for age, sex, and duration of diabetes, were recruited. The clinical and biochemical parameters were measured in each patient. DPN was diagnosed based on neuropathy symptom score and neuropathy deficit score. Motor and sensory nerve conduction velocities were measured by electromyography. Body fat mass was estimated by dual-energy X-ray absorptiometry, while hepatic steatosis was evaluated by ultrasonography. RESULTS: The group with obesity had a significant higher prevalence of DPN (66.62%) than that (46.99%) of the group with normal weight. Compared to the patients with normal weight, the sural sensory nerve in the right lower limbs of the patients with obesity was more susceptible to damage. Hypertriglyceridemia in the patients with obesity was a significant independent risk factor for DPN (odds ratio [OR], 3.90 [95% confidence interval (CI), 1.01 to 15.02]; P = .04), while the duration of diabetes (OR, 1.33 [95% CI, 1.07 to 1.65]; P<.01) and leg subcutaneous fat mass (OR, 0.72 [95% CI, 0.57 to 0.90]; P<.01) in the patients with normal weight were independent risk factors for DPN. The presence of obesity alone in patients with T2DM could predict high DPN risk (OR, 3.09 [95% CI, 1.11 to 8.65]; P = .04). CONCLUSION: Reducing total body adiposity and triglyceride levels, as well as avoiding leg subcutaneous fat atrophy, could be new prevention strategies for DPN in Chinese patients with T2DM. ABBREVIATIONS: ALB = albumin; ALT = alanine transaminase; AST = aspartate transaminase; AUC = area under the curve; AUCc-p/AUCglu = AUC of C-peptide/AUC of glucose; BMI = body mass index; BP = blood pressure; CI = confidence interval; Cr = creatinine; DBP = diastolic blood pressure; DPN = diabetic peripheral neuropathy; FC-P = fasting C-peptide; FPG = fasting plasma glucose; FFA = free fatty acid; γ-GGT = γ-glutamyl transferase; HbA1c = glycated hemoglobin A1c; HDL-C = high-density-lipoprotein cholesterol; ISI = insulin sensitivity index; ISSI-2 = insulin secretion-sensitivity index-2; LDL-C = low-density-lipoprotein cholesterol; MNCS = motor nerve conduction velocity; OGTT = oral glucose tolerance test; PG = plasma glucose; SAT = subcutaneous adipose tissue; SBP = systolic blood pressure; SNCS = sensory nerve conduction velocity; T2DM = type 2 diabetes mellitus; TC = total cholesterol; TG = triglyceride; UA = uric acid; VAT = visceral adipose tissue; WC = waist circumference.

Role of neutrophil extracellular traps in chronic kidney injury induced by bisphenol-A.

Bisphenol-A (BPA) is a common environmental pollutant, and exposure to it is associated with proteinuria and may predict the progression of chronic kidney disease，however, the mechanism is not clear. Neutrophil extracellular traps (NETs) is a DNA skeleton coated with various proteases, and it is associated with various autoimmune nephritis. In this study, we examine whether NETs is involved in BPA-induced chronic kidney injury. In vivo, BPA exposure resulted in impaired renal function and altered renal morphology, including glomerular mesangial matrix expansion and increased renal interstitial fibroblast markers. Meanwhile, more dsDNA can be detected in the serum, and the NETs-associated proteins, MPO and citH3 were deposited in the renal system. In vitro, BPA and NETs treatment caused podocyte injury, a loss of marker proteins, and disorder in the actin skeleton. After NETs inhibition via DNase administration, BPA-induced injuries were significantly relieved. In conclusion, the increase of NETosis in circulation and the renal system during BPA exposure suggests that NETs may be involved in BPA-induced chronic kidney injury.

[Determination of indoles in plasma of polycystic ovarian syndrome patients by high performance liquid chromatography-fluorescence detection].

A new method was established for the determination of indoles (indole (IND), 3-methylindole (3-MI), indolyl-3-acetic acid (IAA) and indolyl-3-propionic acid (IPA)) in plasma by high performance liquid chromatography-fluorescence detection (HPLC-FLD). The analytes were separated simultaneously on a Shim-pack VP-ODS column (150 mm×4.6 mm, 4.6 µm) using 15 mmol/L sodium dihydrogen phosphate solution and methanol (48:52, v/v) as the mobile phases. The column temperature was 30 ℃, and the flow rate was 0.8 mL/min. The calibration curves of IND, 3-MI, IPA and IAA showed good linear relationships. The intra-day and inter-day relative standard deviations (RSDs) for the analytes were both less than 6.31%. The average recoveries of the analytes in plasma were 97.5%-107.0%. The method was successfully applied to the analysis of indoles in the plasma of healthy women of reproductive age (n=25) as controls and patients with polycystic ovarian syndrome (n=61). The results showed that the concentrations of indoles in the plasma were significantly different between the two groups, and IND was found to be a risk factor and a potential diagnostic biomarker for polycystic ovarian syndrome (PCOS). The method is simple, sensitive and suitable for use in clinical testing and laboratory research.

Age-Related Cutoffs of Plasma Aldosterone/Renin Concentration for Primary Aldosteronism Screening.

AIM: This retrospective study is aimed at investigating whether aldosterone-renin ratio (ARR) cutoffs calculated by the plasma aldosterone concentration (PAC)/plasma renin concentration (PRC) should be set differently in patients of different ages. METHODS: 521 hypertensive patients were screened for primary aldosteronism (PA) by the PAC/PRC. 174 patients diagnosed with PA and 311 patients with essential hypertension (EH) were included in the final analysis. Subjects were subdivided into four age groups: <40, 40-49, 50-59, and ≥60 years old. RESULTS: The accuracy of the ARR varied greatly among the different age groups. An ARR of 3.7 (ng/dl)/(µIU/ml) had a sensitivity of 100% and a specificity of 80% in patients ≥ 60 years old. With this cutoff, the sensitivities in patients < 40, 40-49, and 50-59 years old were 74%, 82%, and 87%, respectively, and the specificities were 94%, 95%, and 94%, respectively. To achieve a sensitivity higher than 90%, the ARR cutoff needed to be lowered to 2.0 (ng/dl)/(µIU/ml) for patients 40-49 and 50-59 years old, resulting in sensitivities of 90% and 95%, respectively, and specificities of 80% and 84%, respectively. To achieve a sensitivity higher than 90%, the ARR cutoff needed to be lowered to 1.0 (ng/dl)/(µIU/ml) for patients < 40 years old, resulting in a sensitivity of 90% and a specificity of 82%. CONCLUSIONS: An ARR of 3.7 (ng/dl)/(µIU/ml) is optimal for patients ≥ 60 years; for patients 40-59 years, the optimal ARR cutoff is 2.0; for those younger than 40 years, an ARR of 1.0 may be more reasonable.

Postmenopausal osteoporosis is associated with elevated aldosterone/renin ratio.

Plasma aldosterone/renin ratio (ARR) is a useful method for primary aldosteronism (PA) screening. However some confounders, such as medications and dietary, affect plasma renin and aldosterone levels, resulting in false-negative or -positive plasma ARR. This study investigated the association between postmenopausal osteoporosis (PMO) and plasma ARR. Bone mineral density (BMD) was measured by dual-energy X-ray-absorptiometry (DXA) in 324 normotensive postmenopausal women. Based on clinical characteristics and BMD, 186 and 96 subjects were diagnosed as PMO and osteopenia respectively, and the remaining 42 subjects were grouped as normal BMD. Plasma aldosterone concentration (PAC), plasma renin concentration (PRC), parathyroid hormone (PTH), bone alkaline phosphatase (BALP) and 25-Hydroxyvitamin D(25-(OH)D) were determined. Subjects with PMO showed significantly higher levels of PAC (121.0 ± 78.8 vs. 81.8 ± 71.5 pg/ml, p < 0.01 and 121.0 ± 78.8 vs. 91.7 ± 56.2 pg/ml, p < 0.01) and ARR (32.0 ± 53.6 vs. 9.0 ± 9.3 pg/µU, p < 0.01 and 32.0 ± 53.6 vs. 16.3 ± 32.1 pg/µU, p < 0.01) compared to women with normal BMD and osteopenia, respectively. Using ARR ≥ 37.0 pg/µU as the cutoff for positive screening, more false-positive was found in the PMO group when compared to the normal BMD group (24 vs. 2%) and osteopenia group (24 vs. 7%), respectively. PAC was negatively associated with lumbar spine BMD T-score (r = -0.239, p < 0.001), femur neck BMD T-score (r = -0.234, p < 0.001) and total hip BMD T-score (r = -0.228, p < 0.001). PTH was positively associated with PAC (r = 0.119, p < 0.05) and ARR (r = 0.136, p < 0.05). PAC and ARR are elevated in women with PMO, which might increase the risk of false-positive for case detection of PA.

Bisphenol A is not associated with a 5-year incidence of type 2 diabetes: a prospective nested case-control study.

AIMS: The relationship between bisphenol A (BPA) and diabetes remains controversial. This study aims to investigate whether serum BPA level could predict the 5-year incidence of type 2 diabetes (T2D). METHODS: A nested case-control study was performed among Chinese who participated in the environment, inflammation and metabolic diseases study (2008-2013). Of the 3510 subjects who were free of diabetes, 232 subjects developed diabetes during the 5-year follow-up. Cases and controls were matched for age and gender by a ratio of 1:1. Homoeostasis model assessment was used to estimate basal ß-cell function (HOMA-ß) and insulin resistance (HOMA-IR). Participants were stratified into tertiles based on low, median and high baseline serum BPA levels. Regression models were used to analyze the relationship between serum BPA concentration and the incidence of T2D. RESULTS: At baseline, no significant difference in serum BPA concentration was observed between patients with T2D and controls [1.3 (0.3, 3.7) vs. 1.6 (0.4, 3.9) µmol/L, P = 0.199]; serum BPA concentration was positively associated with fasting plasma glucose (r = 0.27, P < 0.001); however, neither HOMA-ß nor HOMA-IR correlated with serum BPA concentration. During the follow-up, baseline BPA levels could not predict the 5-year T2D incidence, whether or not adjusted for the potential confounders such as body mass index and blood pressure. [Low BPA tertile was the reference, OR 0.66 (95% CI 0.30, 1.44) for median, OR 0.93 (95% CI 0.41, 2.13) for high.] CONCLUSION: BPA is not associated with a 5-year T2D incidence. These data do not support previous cross-sectional study that BPA exerted a detrimental effect on glucose metabolism.

Confirmatory Tests for the Diagnosis of Primary Aldosteronism: A Prospective Diagnostic Accuracy Study.

The diagnosis of primary aldosteronism typically requires at least one confirmatory test. The fludrocortisone suppression test is generally accepted as a reliable confirmatory test, but it is cumbersome. Evidence from accuracy studies of the saline infusion test (SIT) and the captopril challenge test (CCT) has provided conflicting results. This prospective study aimed to evaluate the diagnostic accuracy of the SIT and CCT using fludrocortisone suppression test as the reference standard. One hundred thirty-five patients diagnosed with primary aldosteronism and 101 patients diagnosed with essential hypertension who completed the 3 confirmatory tests were included for the diagnostic accuracy analysis. The areas under the receiver-operator characteristics curves of the CCT and SIT were 0.96 (95% confidence interval [CI], 0.92-0.98) and 0.96 (95% CI, 0.92-0.98), respectively, using post-test plasma aldosterone concentration (PAC) for diagnosis. However, the areas under the receiver-operator characteristics curves of the CCT decreased to 0.71 (95% CI, 0.65-0.77) when the PAC suppression percentage was used to diagnose primary aldosteronism. The optimal cutoff of PAC post-CCT was set at 11 ng/dL, resulting in a sensitivity of 0.90 (95% CI, 0.84-0.95) and a specificity of 0.90 (95% CI, 0.83-0.95), which were not significantly different from those of SIT (with PAC post-SIT set at 8 ng/dL, sensitivity: 0.85 [95% CI, 0.78-0.91], P=0.192; specificity: 0.92 [95% CI, 0.85-0.97], P=0.551). In conclusion, both CCT and SIT are accurate alternatives to the more complex fludrocortisone suppression test. Because CCT is safe and much easier to perform, it may serve as a more feasible alternative. When interpreting the results of CCT, PAC post-CCT is highly recommended.

High specificity of spot urinary free metanephrines in diagnosis and prognosis of pheochromocytomas and paragangliomas by HPLC with electrochemical detection.

BACKGROUND: The metanephrines (MNs) in plasma and urine were proposed as biomarkers for the diagnosis of pheochromocytomas and paragangliomas (PPGLs). However, plasma free MNs and 24h urinary fractionated MNs were not satisfactory enough in specificity for the diagnosis of PPGLs. Moreover, the collection of 24h urine was inconvenient. This work examined the diagnostic and prognostic efficiency of free MNs in spot urine for PPGLs. METHODS: We measured free MNs concentration in spot urine and plasma of 28 PPGLs patients and 155 control subjects by HPLC with electrochemical detection. Postoperative free MNs levels in spot urine and plasma of 14 PPGLs patients were also determined. Creatinine (Cr) concentration was used for the correction of urine volume. RESULTS: The specificity of spot urinary free MNs/Cr in the diagnosis of PPGLs was significantly higher than that of plasma free MNs [normetanephrine (NMN), 98.7% (95.4%-99.8%) vs 93.0% (87.4%-96.6%); metanephrine (MN), 93.6% (88.5%-96.9%) vs 84.5% (77.5%-90.0%)]. Meanwhile, the positive likelihood ratios for spot urinary free NMN/Cr and MN/Cr were 69.21 and 13.29, compared with 12.68 and 5.30 for plasma free NMN and MN, respectively. For the PPGLs patients underwent surgery, the plasma free MNs level appeared an abnormal elevation and yielded false-positive results for some patients. Our findings were validated in an independent cohort, resulting in the specificity of 100% for both urinary free NMN/Cr and MN/Cr, and 97.3% and 83.8% for plasma free NMN and MN, respectively. CONCLUSIONS: Spot urinary free MNs/Cr, superior to plasma free MNs, presented a promising biomarker for the diagnosis and prognosis of PPGLs.

[Simultaneous determination of plasma indole and skatole in pregnant women with hepatitis B virus infection by high performance liquid chromatography].

A high performance liquid chromatographic (HPLC) method with fluorescence detection (FD) was established to simultaneously determine plasma indole and skatole. Plasma samples were pretreated by liquid-liquid extraction. Chromatographic separation was accomplished on a Shim-Pack VP-ODS column (150 mm×4. 6 mm, 4.6 µ m) using an isocratic mixture of 15 mmol/L sodium dihydrogen phosphate solution and methanol (40:60, v/v). The fluorescence excitation and emission wavelengths were 274 nm and 340 nm, respectively. The linear ranges were 2.22-88.89 µ g/L for indole and 1.11-44.44 µ g/L for skatole. The detection limits were 0.11 µ g/L and 0.06 µ g/L for indole and skatole, respectively. The recoveries were in the range of 95.5%-112.3% with the relative standard deviations less than 6.8%. The method was successfully applied to the analysis of plasma from healthy pregnant women (n=46) and pregnant women with hepatitis B virus (HBV) infection (n=29). The results showed that plasma indole and skatole levels were significantly different between two groups. In pregnant women with HBV infection, the concentrations of indolic compounds were positively associated with transaminase levels.

Direct electrochemical measurement of metanephrines in spot urine samples for the diagnosis of phaeochromocytomas.

Metanephrines (MNs) were suggested as a potential first-line biochemical index for the diagnosis of phaeochromocytomas (PHEO). In this study, we developed a simple electrochemical method for the quantitative measurement of MNs in spot urine samples. As MNs contain a hydroxyphenyl group, they could be oxidized at a certain potential to quinines, which could be further detected by the differential pulse voltammetry (DPV) method using unmodified screen-printed carbon electrode (SPCE). Meanwhile, the solid phase extraction (SPE) technique was used to eliminate the matrix effect in the samples. Consequently, free MNs from the extracted urine sample were screened in a linear range from 0.25 mg/L to 12.5 mg/L. The lowest limit of quantification (LLOQ) for MNs was 0.25 mg/L and the limit of detection (LOD) was 0.05 mg/L. Both the precisions and recoveries were sufficient for clinical applications. The urine samples from 22 patients with PHEO and 63 controls were analyzed by the proposed method. The area under the ROC curve was 0.981 (95% CI, 0.958-1.000) with the sensitivity of 95.5% and the specificity of 92.4% at the cut-off value of 0.404 mg/L in these urine samples. Overall, the proposed method provides a cost-effective, rapid and simple tool for clinical diagnosis of PHEO.

An electrochemical sensor for indole in plasma based on MWCNTs-chitosan modified screen-printed carbon electrode.

Indole is an essential metabolite in intestinal tract. The dysregulation of plasma indole concentration occurred in various diseases. In this study, the indole in plasma was determined directly using electrochemical sensor with multiwall carbon nanotubes-chitosan (MWCNTs-CS) modified screen-printed carbon electrode (SPCE). The electrochemical behavior of indole was elucidated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) on the MWCNTs-CS composites modified SPCE (MWCNTs-CS/SPCE). The results showed that the current responses of indole improved greatly due to the high catalytic activity and electron transfer reaction of nano-composites. Under the optimized conditions, the linear range of indole was from 5 to 100µgL-1 with the detection limit of 0.5µgL-1 (S/N = 3). This novel electrochemical sensor exhibited acceptable accuracies and precisions with the variations less than 7.3% and 9.0%, respectively. Furthermore, high performance liquid chromatography (HPLC) method was utilized to compare with the established electrochemical method for the determination of indole in plasma. The results showed a high correlation between the two methods. At last, the electrochemical sensor was successfully applied to detect the level of indole in plasma samples with satisfactory selectivity and sensitivity. The concentrations of plasma indole in healthy pregnant women and gestational diabetes mellitus (GDM) patients were 5.3 (4.1-7.0)µgL-1 and 7.2 (4.5-9.4)µgL-1, respectively.

Altered Circulating Inflammatory Cytokines Are Associated with Anovulatory Polycystic Ovary Syndrome (PCOS) Women Resistant to Clomiphene Citrate Treatment.

BACKGROUND Polycystic ovary syndrome (PCOS) is a common gynecological disease characterized by chronic oligoanovulation, clinical/biochemical hyperandrogenism, polycystic ovaries, and insulin resistance. Accumulating evidence has shown that PCOS-related ovarian dysfunction is the main cause of anovulatory infertility. Clomiphene citrate (CC) is the first-line therapy for PCOS patients; however, approximately 15-40% PCOS patients are resistant to CC treatment. It has been demonstrated that PCOS is a chronic pro-inflammatory state, as some pro-inflammatory cytokines were elevated in the peripheral circulation of PCOS patients, but whether altered inflammatory cytokines expression in PCOS patients is associated with blunted response to CC remains unknown. MATERIAL AND METHODS We recruited 44 CC-resistant PCOS patients, along with 55 age and body mass index (BMI)-matched CC-sensitive PCOS patients. Ovulation was induced by administrating 50-100 mg/day CC on days 5 to 9 of each menstrual cycle. The cytokine profiles were detected by cytokine antibody microarrays and further validated by ELISAs. RESULTS CC-resistant patients had higher levels of high-sensitivity C-reactive protein (hsCRP) than the CC-sensitive individuals. A growth factor, angiopoietin-2, was significantly reduced [1.64 (0.93-1.95) vs. 1.08 (0.85-1.34), p<0.05], while a chemokine CXCL-16 was significantly increased (9.10±2.35 vs. 10.41±2.82, p<0.05) in CC-resistant patients compared to the CC-sensitive subjects. CXCL-16 was positively correlated with hsCRP (r=0.33, p<0.01). Logistic regression analysis showed that angiopoietin-2 and CXCL-16 are associated with CC resistance. CONCLUSIONS Circulating cytokines are disturbed in CC-resistant PCOS patients. Altered angiopoietin-2 and CXCL-16 levels might compromise the responsiveness of the ovary to CC through up-regulating angiogenesis and inflammation.