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The relationship of adipose tissue insulin resistance (AT-IR, a product of fasting insulin and free fatty acids) and homeostasis-model assessment-insulin resistance (HOMA-IR) to ß-cell function was studied cross-sectionally in the setting of subtle glucose dysregulation. Associations of AT-IR and HOMA-IR with fasting and post-glucose glycemia and ß-cell function inferred from serum insulin kinetics during a 75 g oral glucose tolerance test were studied in 168 young female Japanese students. ß-cell function was evaluated by disposition index calculated as a product of the insulinogenic index (IGI) and Matsuda index. AT-IR, not HOMA-IR, showed positive associations with post-glucose glycemia and area under the glucose response curve although both indices were associated with fasting glycemia. HOMA-IR, not AT-IR, was associated positively with log IGI whereas both indices were inversely associated with Matsuda index. AT-IR, not HOMA-IR, showed inverse associations with log disposition index. Associations of adipose tissue insulin resistance with ß-cell function (inverse) and glucose excursion in young Japanese women may suggest that lipotoxicity to pancreatic ß-cells for decades may be associated with ß cell dysfunction found in Japanese patients with type 2 diabetes. Positive association of HOMA-IR with insulinogenic index may be associated with compensatory increased insulin secretion.
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Tecido Adiposo , Glicemia , Teste de Tolerância a Glucose , Resistência à Insulina , Células Secretoras de Insulina , Insulina , Humanos , Feminino , Células Secretoras de Insulina/metabolismo , Tecido Adiposo/metabolismo , Glicemia/metabolismo , Adulto Jovem , Adulto , Japão , Insulina/sangue , Insulina/metabolismo , Estudos Transversais , Jejum/sangue , População do Leste AsiáticoRESUMO
Background Malondialdehyde (MDA) and nitric oxide (NO) are considered specific biomarkers for oxidative stress. Oxidative stress in prediabetics with an augmented potential for the onset of diabetes is at least partly responsible for the various complications of diabetes. Evidence shows that the early features of cell injury are due to transient acute elevations in blood glucose. This study aims to determine whether oxidative stress in prediabetic young adults increases the risk of developing diabetes. Aim and objectives We envisaged a study to determine whether the parameters representing oxidative stress are deranged in prediabetics. Materials and methods The study was conducted on prediabetic young individuals from 18 to 35 years, screened from the tertiary-level hospital, and a similar group of non-prediabetic young individuals identified from the same in a tertiary-level hospital in India. Results We observed significant elevations in prediabetics in the following oxidative stress parameters: MDA (P= <0.001), and NO (P= <0.001); indicating that these parameters were significantly higher among the prediabetics than the controls. We also observed significantly greater body weight, waist circumference, and BMI among the prediabetics than the controls. Conclusion Early identification and appropriate treatment of hyperglycemia in prediabetics is essential, as impairments in pancreatic beta-cell functioning and resistance to insulin are already present before the onset of type 2 diabetes mellitus (T2DM). Owing to the high potential for mortality and morbidity due to cardiovascular diseases (CVDs) as a complication of diabetes, treatment plans must be put in place early enough so that complications can be prevented. Inflammation and oxidative stress may be viewed as valuable targets to hinder the evolution of T2DM from prediabetes.
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BACKGROUND AND AIMS: Insulin resistance (IR) is a risk factor for several cardiometabolic disorders; however, there is conflicting evidence about the reliability of certain IR markers. In this context, the triglyceride-glucose index (TyG) has been proposed as a surrogate marker for IR. This study aimed to compare the TyG index and homeostasis model assessment of insulin resistance (HOMA-IR). METHODS AND RESULTS: A cross-sectional analysis was conducted using baseline data from 11,314 adults (aged 35-74 years) from the ELSA-Brasil study. The correlation between TyG and HOMA-IR, their interrater reliability, and their predictive value in identifying metabolic syndrome (MetS) were assessed. The mean TyG and HOMA-IR in our sample were 8.81 ± 0.52 and 2.78 ± 1.58 for men, and 8.53 ± 0.48 and 2.49 ± 1.38 for women, respectively. TyG and HOMA-IR showed a weak to moderate correlation with each other (Pearson's r for men: 0.395 and 0.409 for women, p-value <0.05) and other markers of glycemic metabolism. Additionally, the area under the curve for the prediction of MetS was greater for TyG than HOMA-IR, regardless of sex (TyG: 0.836 for men and 0.826 for women; HOMA-IR: 0.775 for men and 0.787 for women). The concordance between these markers was low (Cohens kappa coefficient: 0.307 for men and 0.306 for women). Individuals with increased TyG exhibited mainly anthropometrical and glycemic metabolic alterations, whereas those with elevated HOMA-IR displayed mostly lipid-associated metabolic alterations. CONCLUSION: TyG and HOMA-IR might indicate different profiles of cardiometabolic disorders, showing poor agreement in classifying individuals (normal vs. altered) and a weak correlation. Therefore, further studies are needed to investigate the role of TyG as a surrogate marker of IR.
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Dietary intake of live microbes may benefit human health, but less is known about the role in insulin resistance. This study was developed with the goal of evaluating potential relationships between IR and dietary live microbes. The National Health and Nutrition Examination Survey (NHANES) dataset was leveraged to collect data from 6,333 subjects 18 + years of age. The Sanders system for the classification of dietary live microbe intake (containing Low (< 104 CFU/g), Medium (104-107 CFU/g), or High (> 107 CFU/g) levels of live microbes) was then used to separate these patients into three groups (low, medium, or high). Fasting blood glucose and insulin levels were used to approximate IR based on the homeostasis model of insulin resistance (HOMA-IR). Weighted linear regressions were used to assess the relationship between IR and live microbe intake. After fully adjusting for confounding factors, subjects in the groups exhibiting medium and high levels of live microbe intake exhibited HOMA-IR scores that were below those of subjects in the low group. The relationship between live microbe intake and HOMA-IR scores was also potentially impacted by ethnicity. In summary, a negative correlation was detected between dietary live microbe intake and HOMA-IR values.
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Resistência à Insulina , Inquéritos Nutricionais , Humanos , Masculino , Adulto , Estudos Transversais , Feminino , Pessoa de Meia-Idade , Estados Unidos , Dieta , Glicemia/metabolismo , Adulto Jovem , Insulina/sangue , Insulina/metabolismo , Adolescente , IdosoRESUMO
Ecological restoration is imperative for controlling desertification. Potential natural vegetation (PNV), the theoretical vegetation succession state, can guides near-natural restoration. Although a rising transition from traditional statistical methods to advanced machine learning and deep learning is observed in PNV simulation, a comprehensive comparison of their performance is still unexplored. Therefore, we overview the performance of PNV mapping in terms of 12 commonly used methods with varying spatial scales and sample sizes. Our findings indicate that the methodology should be carefully selected due to the variation in performance of different model types, with Area Under the Curve (AUC) values ranging from 0.65 to 0.95 for models with sample sizes up to 80% of the total sample size. Specifically, semi-supervised learning performs best with small sample sizes (i.e., 10 to 200), while Random Forest, XGBoost, and artificial neural networks perform better with large sample sizes (i.e., over 500). Further, the performance of all models tends to improve significantly as the sample size increases and the grain size of the crystals becomes smaller. Take the downstream Tarim River Basin, a hyper-arid region undergoing ecological restoration, as a case study. We showed that its potential restored areas were overestimated by 2-3 fold as the spatial scale became coarser, revealing the caution needed while planning restoration projects at coarse resolution. These findings enhance the application of PNV in the design of restoration programs to prevent desertification.
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Conservação dos Recursos Naturais , Redes Neurais de Computação , Ecossistema , Ecologia , Aprendizado de Máquina , Plantas , Modelos TeóricosRESUMO
Associations of adipose tissue insulin resistance index (AT-IR, a product of fasting insulin and free fatty acids) with body fat mass and distribution and appendicular skeletal muscle mass (ASM) were compared with results of homeostasis-model assessment-insulin resistance (HOMA-IR) in 284 Japanese female university students and 148 their biological mothers whose BMI averaged < 23 kg/m2. Although mothers compared with daughters had higher BMI, body fat percentage, trunk fat to body fat (TF/BF) ratio and lower leg fat to body fat (LF/BF), AT-IR and HOMA-IR did not differ. We had multivariable linear regression analyses which included TF/BF ratio, LF/BF ratio, weight-adjusted ASM (%ASM), height-adjusted ASM index (ASMI), fat mass index (FMI), and body fat percentage. In young women, AT-IR was independently associated with LF/BF ratio (Standardized ß [Sß]: - 0.139, p = 0.019) and ASMI (Sß: - 0.167, p = 0.005). In middle-aged women, LF/BF ratio (Sß: - 0.177, p = 0.049) and %ASM (Sß: - 0.205, p = 0.02) emerged as independent determinants of AT-IR. HOMA-IR was associated with TF/BF ratio and FMI, a proxy of abdominal and general adiposity, respectively, in both young and middle-aged women. The inverse association of AT-IR with leg fat may support the notion that limited peripheral adipose storage capacity and small skeletal muscle size are important etiological components in insulin-resistant cardiometabolic disease in Japanese women.
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Tecido Adiposo , Resistência à Insulina , Músculo Esquelético , Humanos , Feminino , Músculo Esquelético/metabolismo , Adulto , Tecido Adiposo/metabolismo , Japão , Pessoa de Meia-Idade , Índice de Massa Corporal , Adulto Jovem , Insulina/sangue , Insulina/metabolismo , Adiposidade , População do Leste AsiáticoRESUMO
Prediabetes is a condition when the blood glucose levels are above the normal range but below the threshold for defining diabetes. Previously considered benign, it is now recognized to be associated with various macrovascular and microvascular complications, with increases in the risk of cardiovascular events, nephropathy neuropathy, and retinopathy. Early identification of prediabetics may help detect the risk for these future complications at an earlier stage. Moreover, therapeutic options for prediabetes are available, which can retard its progression to diabetes and the subsequent development of complications. Hence, we make a case for the early identification of prediabetes through screening methods and appropriate institution of management strategies.
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The triglyceride-glucose (TyG) index is a simple and inexpensive new marker of insulin resistance that is being increasingly used for the clinical prediction of metabolic syndrome (MetS). Nevertheless, there are only a few comparative studies on its predictive capacity for MetS versus those using the traditional homeostasis model assessment (HOMA). We conducted a cross-sectional study using a database from the National Health and Nutrition Examination Survey (1999 March to 2020 pre-pandemic period). Using statistical methods, we compared the predictive abilities of the TyG index and HOMA (including HOMA of insulin resistance [HOMA-IR] and HOMA of beta-cell function [HOMA-ß]) for MetS. A total of 34,195 participants were enrolled and divided into the MetS group (23.1%) or no MetS group (76.9%) according to the International Diabetes Federation (IDF) diagnostic criteria. After applying weighted data, the baseline characteristics of the population were described. Following the exclusion of medication influences, the final count was 31,304 participants. Receiver operating characteristic curve analysis revealed that while distinguishing between MetS and no MetS, the TyG index had an area under the curve (AUC) of 0.827 (sensitivity = 71.9%, specificity = 80.5%), and the cutoff was 8.75, slightly outperforming HOMA-IR (AUC = 0.784) and HOMA-ß (AUC = 0.614) with a significance of P < 0.01. The prevalence of MetS in the total population calculated using the TyG index cutoff value was 30.9%, which was higher than that reported in the IDF diagnostic criteria. Weighted data analysis using univariate and multivariate logistic regression displayed an independent association between elevated TyG and HOMA-IR with the risk of MetS. Subgroup analysis further revealed differences in the predictive ability of the TyG index among adult populations across various genders and ethnicities, whereas such differences were not observed for children and adolescents. The TyG index is slightly better than HOMA in predicting MetS and may identify more patients with MetS; thus, its applications in a clinical setting can be appropriately increased.
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Glicemia , Homeostase , Resistência à Insulina , Síndrome Metabólica , Inquéritos Nutricionais , Triglicerídeos , Humanos , Síndrome Metabólica/sangue , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Masculino , Feminino , Triglicerídeos/sangue , Pessoa de Meia-Idade , Glicemia/análise , Glicemia/metabolismo , Estudos Transversais , Adulto , Curva ROC , Biomarcadores/sangue , IdosoRESUMO
BACKGROUND: The weight-adjusted waist index (WWI) is a recently developed obesity metric, and the aim of this study was to investigate the relationship between physical activity (PA) and WWI and the homeostasis model assessment of insulin resistance (HOMA-IR) in adolescents, as well as the joint association of HOMA-IR. METHODS: This study was based on the National Health and Nutrition Survey conducted between 2013 and 2016 and included 1024 adolescents whose median age was 15.4. Multivariate linear regression was used to examine the associations between HOMA-IR and PA and WWI. Using generalized additive models, a potential nonlinear link between WWI and HOMA-IR was evaluated. Subgroup analysis was also carried out. RESULTS: The fully adjusted model revealed a positive association (ß: 0.48, 95% CI: 0.43, 0.53) between the WWI and HOMA-IR. The HOMA-IR was lower in physically active (ß: -0.16, 95% CI: -0.26, -0.05) participants versus inactive participants. Participants who had higher WWI and were not physically active (ß: 0.69; 95% CI: 0.56, 0.82) had the highest levels of HOMA-IR compared to participants who had lower WWI and were physically active. Subgroup analysis revealed that these correlations were similar in males and females. CONCLUSION: Our results demonstrated that higher WWI and PA were associated with a lower HOMA-IR and that WWI and PA had a combined association with HOMA-IR. The findings of this study are informative for the preventing insulin resistance in adolescents.
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Exercício Físico , Resistência à Insulina , Humanos , Masculino , Feminino , Adolescente , Estudos Transversais , Exercício Físico/fisiologia , Circunferência da Cintura , Peso Corporal/fisiologia , Índice de Massa Corporal , Inquéritos NutricionaisRESUMO
BACKGROUND: Epidemiological studies regarding the correlation between anti-Müllerian hormone (AMH) and insulin resistance (IR) in polycystic ovarian syndrome (PCOS) remain inconsistent. The primary aim of this study was to determine the correlations between AMH and IR in patients with PCOS and to explore the selected factors that influence the correlations. METHODS: We conducted systemic searches of online databases (PubMed, Science Direct, Taylor and Francis, Scopus, and ProQuest) from inception to December 20, 2023 and manual searches of the associated bibliographies to identify relevant studies. We then performed subgroup and sensitivity analyses to explore the sources of heterogeneity, followed by a publication bias risk assessment of the included studies using the Joanna Briggs Institute critical appraisal tool. We used a random-effects model to estimate the pooled correlations between AMH and the homeostatic model assessment for insulin resistance (HOMA-IR) in patients with polycystic ovarian syndrome (PCOS). RESULTS: Of the 4835 articles identified, 22 eligible relevant studies from three regions were included and identified as low risk of bias. The random-effects pooled correlation estimate was 0.089 (95% confidence interval [CI]: -0.040, 0.215), with substantial heterogeneity (I2 = 87%; τ2 = 0.0475, p < .001). Subgroup analyses showed that the study region did not influence the correlation estimates, and sensitivity analysis showed no significant alteration in the pooled correlation estimate or 95% CI values. No publication bias was observed. CONCLUSION: There was a weak, statistically insignificant correlation between AMH and HOMA-IR in patients with PCOS. The correlation estimates did not vary according to the study participants' regions.
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Hormônio Antimülleriano , Resistência à Insulina , Síndrome do Ovário Policístico , Síndrome do Ovário Policístico/sangue , Síndrome do Ovário Policístico/metabolismo , Humanos , Hormônio Antimülleriano/sangue , FemininoRESUMO
Early GDM is associated with adverse pregnancy outcomes, however data on other outcomes are scarce. We evaluated women with early (n = 117) and classical (n = 412) GDM for long-term postpartum (median 32 months) glycemic and cardiometabolic outcomes and found a significantly higher prevalence of diabetes in the former [22.2 % vs. 12.6 %, p = 0.010].
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Diabetes Gestacional , Período Pós-Parto , Humanos , Feminino , Diabetes Gestacional/epidemiologia , Gravidez , Adulto , Índia/epidemiologia , Glicemia/metabolismo , Glicemia/análise , Resultado da Gravidez/epidemiologia , PrevalênciaRESUMO
Both high serum insulin-like growth factor-binding protein-1 (s-IGFBP-1) and insulin resistance (IR) are associated with poor functional outcome poststroke, whereas overweight body mass index (BMI; 25-30) is related to fewer deaths and favorable functional outcome in a phenomenon labeled "the obesity paradox". Furthermore, IGFBP-1 is inversely related to BMI, in contrast to the linear relation between IR and BMI. Here, we investigated s-IGFBP-1 and IR concerning BMI and 7-year poststroke functional outcome. We included 451 stroke patients from the Sahlgrenska Study on Ischemic Stroke (SAHLSIS) with baseline measurements of s-IGFBP1, homeostasis model assessment of IR (HOMA-IR), BMI (categories: normal-weight (8.5-25), overweight (25-30), and obesity (>30)), and high-sensitivity C-reactive protein (hs-CRP) as a measure of general inflammation. Associations with poor functional outcome (modified Rankin scale [mRS] score: 3-6) after 7 years were evaluated using multivariable binary logistic regression, with overweight as reference due to the nonlinear relationship. Both normal-weight (odds-ratio [OR] 2.32, 95% confidence interval [CI] 1.30-4.14) and obese (OR 2.25, 95% CI 1.08-4.71) patients had an increased risk of poor functional outcome, driven by deaths only in the normal-weight. In normal-weight, s-IGFBP-1 modestly attenuated (8.3%) this association. In the obese, the association was instead attenuated by HOMA-IR (22.4%) and hs-CRP (10.4%). Thus, a nonlinear relation between BMI and poor 7-year functional outcome was differently attenuated in the normal-weight and the obese.
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Índice de Massa Corporal , Inflamação , Resistência à Insulina , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina , Humanos , Feminino , Masculino , Idoso , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Inflamação/metabolismo , Inflamação/sangue , Pessoa de Meia-Idade , Obesidade/metabolismo , Obesidade/complicações , Obesidade/sangue , Acidente Vascular Cerebral/metabolismo , Proteína C-Reativa/metabolismo , Biomarcadores/sangue , Sobrepeso/metabolismo , Sobrepeso/sangue , Peptídeos Semelhantes à InsulinaRESUMO
Objectives: To determine the association of triglyceride-glucose index with homeostasis model assessment of insulin resistance in type 2 diabetes mellitus patients, and to determine the association of triglyceride-glucose index with urinary albumin-to-creatinine ratio for predicting diabetic nephropathy. METHODS: The observational, cross-sectional study was conducted from September 2021 to September 2022 at the Department of Chemical Pathology, Pakistan Railway Hospital, Rawalpindi, Pakistan and comprised recently-diagnosed type 2 diabetes mellitus patients. Recorded data included age, gender, vitals, diabetes duration, body mass index and other pertinent demographic and clinical information. Measurements included spot urine albumin-to-creatinine ratio, triglycerideglucose index, homeostasis model assesment of insulin resistance as well as fasting serum insulin, fasting plasma glucose, glycosylated haemoglobin, triglycerides, total cholesterol and serum creatinine. On the basis of triglyceride-glucose index scores, the participants were divided into 4 quartiles; Q1=4.5-5, Q2=5.1-5.5, Q3=5.6-6, and Q4=>6. Data was analysed using SPSS 26. RESULTS: Of the 218 patients, 141(64.7%) were females and 77(35.3%) were males. The overall mean age was 49.22±11.46 years. There were 102(46.8%) overweight patients, 33(15.1%) obese and 82(37.2%) had normal weight. There were 58(26.6%) patients in Q1, 86(39.4%) in Q2, 46(21.1%) in Q3 and 28(12.8%) in Q4. Those in Q4 showed elevated fasting plasma glucose, glycated haemoglobin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, homeostasis model assessment of insulin resistance and urine albumin-to-creatinine ratio (p<0.05), as well as low values for high-density lipoprotein cholesterol and estimated glomerular filtration rate(p<0.05). Fasting serum insulin was negatively linked to glycated haemoglobin (r=-0.12, p=0.07). Triglyceride-glucose index (r=0.76, p<0.001), homeostasis model assessment of insulin resistance (r=0.48, p<0.001), and urine albumin-to-creatinine ratio (r=0.10,p=0.05) positively correlated with glycated haemoglobin. Fasting serum insulin (r=-0.13, p=0.05), negatively correlated with triglyceride-glucose index, while homeostasis model assessment of insulin resistance (r= 0.32, p<0.001) and urine albumin-to-creatinine ratio (r=0.28, p=0.05) had a positive correlation. The estimated glomerular filtration rate was significantly positively linked with fasting serum insulin (r=0.05, p=0.05), and correlated significantly negatively with triglyceride-glucose index (r=-0.35, p=0.01), homeostasis model assessment of insulin resistance (r=-0.01, p=0.86) and urine albumin-to-creatinine ratio (r=-0.02, p=0.8). CONCLUSIONS: The triglyceride-glucose index showed a strong association with homeostasis model assessment of insulin resistance, and surpassed it in terms of predicting diabetic nephropathy in type 2 diabetes mellitus patients.
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Biomarcadores , Glicemia , Creatinina , Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Homeostase , Resistência à Insulina , Triglicerídeos , Humanos , Masculino , Feminino , Triglicerídeos/sangue , Pessoa de Meia-Idade , Nefropatias Diabéticas/diagnóstico , Nefropatias Diabéticas/fisiopatologia , Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Estudos Transversais , Glicemia/metabolismo , Glicemia/análise , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Creatinina/sangue , Creatinina/urina , Albuminúria , Paquistão/epidemiologia , Hemoglobinas Glicadas/metabolismo , Hemoglobinas Glicadas/análise , Colesterol/sangueRESUMO
Background and Aim: This study aimed to clarify the efficacy and safety of 48-week pemafibrate treatment in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) complicated by dyslipidemia. Methods: A total of 110 patients diagnosed with MASLD complicated by dyslipidemia received pemafibrate at a dose of 0.1 mg twice daily for 48 weeks. Results: The participants were 54 males and 37 females, with a median age of 63 (52-71) years. Besides improvement in lipid profile, significant reductions from baseline to 48 weeks of treatment were found in liver-related enzymes, such as aspartate aminotransferase, alanine aminotransferase (ALT), gamma-glutamyl transpeptidase, and alkaline phosphatase (P < 0.001 for all). A significant decrease in the homeostasis model assessment-insulin resistance (HOMA-IR) was observed in patients with insulin resistance (HOMA-IR ≥ 2.5) (4.34 at baseline to 3.89 at Week 48, P < 0.05). Moreover, changes in ALT were weakly correlated with those in HOMA-IR (r = 0.34; p < 0.05). Regarding noninvasive liver fibrosis tests, platelets, Wisteria floribunda agglutinin-positive Mac-2-binding protein, type IV collagen 7s, and the non-alcoholic fatty liver disease fibrosis score significantly decreased from baseline to Week 48. Most adverse events were Grades 1-2, and no drug-related Grade 3 or higher adverse events were observed. Conclusion: This study demonstrated that 48-week pemafibrate administration improved liver-related enzymes and surrogate marker of liver fibrosis in patients with MASLD. The improvement of insulin resistance by pemafibrate may contribute to the favorable effect on MASLD complicated by dyslipidemia.
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Socio-economic activities like food trade can increase the uncertainty of human risk of persistent organic pollutants (POPs). We compared the change in model predicted α-hexachlorocyclohexane (α-HCH) cancer risk (CR) with and without grain trade in mainland China. In scenario without grain logistics, α-HCH moved fast away from southern and southeastern China via northward atmospheric transport. However, the grain logistics from northeastern China delivers the α-HCH previously accumulated in northeastern sink back to densely populated areas in recent years, which enhance CR by >50 % in the southern seaboard of China. The northward movement of grain production center and recent grain deficiency in southern provinces induced by dietary pattern changes is identified as the major driving factors of the reversed transport of α-HCH. The finding highlights the potential of socio-economic activities that can otherwise offset the risk reduction effect of the geochemical cycle of POPs.
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Grão Comestível , Hexaclorocicloexano , China , Hexaclorocicloexano/análise , Humanos , Exposição Ambiental/estatística & dados numéricos , Meios de Transporte , Poluentes Ambientais/análiseRESUMO
Research Highlight: Christian, M., Oosthuizen, W. C., Bester, M. N., & de Bruyn, P. N. (2024). Robustly estimating the demographic contribution of immigration: Simulation, sensitivity analysis and seals. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.14053. Immigration can have profound consequences for local population dynamics and demography, but collecting data to accurately quantifying it is challenging. The recent rise of integrated population models (IPMs) offers an alternative by making it possible to estimate immigration without the need for explicit data, and to quantify its contribution to population dynamics through transient Life Table Response Experiments (tLTREs). Simulation studies have, however, highlighted that this approach can be prone to bias and overestimation. In their new study, Christian et al. address one of the root causes of this issue by improving the estimation of time variation in vital rates and immigration using Gaussian processes in lieu of traditionally used temporal random effects. They demonstrate that IPM-tLTRE frameworks with Gaussian processes produce more accurate and less biased estimates of immigration and its contribution to population dynamics and illustrate the applicability of this approach using a long-term data set on elephant seals (Mirounga leonida). Results are validated with a simulation study and suggest that immigration of breeding females has been central for population recovery of elephant seals despite the species' high female site fidelity. Christian et al. thus present new insights into population regulation of long-lived marine mammals and highlight the potential for using Gaussian process priors in IPMs. They also illustrate a suite of 'best practices' for state-of-the-art IPM-tLTRE analyses and provide an inspirational example for the kind of ecological modelling workflow that can be invaluable not just as a starting point for fellow ecologists picking up or improving their own IPM-tLTRE analyses, but also for teaching and in contexts where model estimates are used for informing management and conservation decision-making.
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Migração Animal , Modelos Biológicos , Dinâmica Populacional , Animais , Focas Verdadeiras/fisiologiaRESUMO
AIM: The response rate to pioglitazone and the predictive factors for its effects on improving liver biochemistry in patients with steatotic liver disease (SLD) remain elusive, so we aimed to investigate these issues. METHODS: A 3-year prospective cohort study of 126 Taiwanese patients with SLD treated with pioglitazone (15-30 mg/day) was conducted. Phospholipase domain-containing protein 3 I148M rs738409, methylenetetrahydrofolate reductase rs1801133, aldehyde dehydrogenase 2 (ALDH2) rs671 and lipoprotein lipase rs10099160 single nucleotide polymorphisms were assessed in the patients. RESULTS: Of 126 patients, 78 (61.9%) were men, and the mean and median ages were 54.3 and 56.5 years, respectively. Pioglitazone responders were defined as those with decreased alanine aminotransferase (ALT) levels at 6 months post-treatment, and 105 (83.3%) patients were responders. Compared with non-responders, responders were more frequently women and had higher baseline ALT levels. The proportion of patients with the ALDH2 rs671 GG genotype was lower among responders (38.6% vs. 66.6%, p = .028). Female sex [odds ratio (OR): 4.514, p = .023] and baseline ALT level (OR: 1.015, p = .046; cut-off level: ≥82 U/L) were associated with pioglitazone response. Among responders, the liver biochemistry and homeostasis model assessment of insulin resistance improved from 6 to 24 months post-treatment. The total cholesterol levels decreased within 6 months, while increases in high-density lipoprotein cholesterol levels and decreases in triglyceride levels and fibrosis-4 scores were noted only at 24 months post-treatment. The 2-year cumulative incidences of cardiovascular events, cancers and hepatic events were similar between responders and non-responders. CONCLUSIONS: Regarding liver biochemistry, over 80% of Taiwanese patients with SLD had a pioglitazone response, which was positively associated with female sex and baseline ALT levels. Insulin resistance improved as early as 6 months post-treatment, while liver fibrosis improvement was not observed until 24 months post-treatment. The link between the pioglitazone response and the ALDH2 genotype warrants further investigation.
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Aldeído-Desidrogenase Mitocondrial , Hipoglicemiantes , Pioglitazona , Polimorfismo de Nucleotídeo Único , Humanos , Pioglitazona/uso terapêutico , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Prospectivos , Hipoglicemiantes/uso terapêutico , Resultado do Tratamento , Aldeído-Desidrogenase Mitocondrial/genética , Taiwan/epidemiologia , Alanina Transaminase/sangue , Tiazolidinedionas/uso terapêutico , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/genética , Idoso , Lipase Lipoproteica/genética , Fígado/efeitos dos fármacos , Fígado/patologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/complicações , Genótipo , AdultoRESUMO
One of the main limitations to the use of fabric-reinforced cementitious matrix (FRCM) composites for the external confinement of masonry is the lack of accurate formulas for estimating the compressive strength and ultimate strain of confined members. With the aim of providing a contribution on the topic, the authors have been carrying out studies on the FRCM-confined masonry for some time and, in a recent study, they proposed some formulations for the prediction of compressive strength. In continuity to that work, an analytical study on the ultimate strain of FRCM-confined masonry is presented in this paper, and preliminary models were derived by considering a wide experimental database compiled from the technical literature. The accuracy of the found relationships was examined based on a comparison with the few formulas published in the literature or reported in international guidelines. To this purpose, it is worth highlighting that the current Italian Guidelines CNR-DT 215/2018 do not provide indications about the estimation of the ultimate strain of FRCM-confined masonry, and the study proposed here attempts to provide a contribution to the mentioned document.
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BACKGROUND: There are little data on changes in insulin sensitivity during the first few years of life following in utero human immunodeficiency virus (HIV) and antiretroviral (ARV) exposure. METHODS: The Tshilo Dikotla study enrolled pregnant persons with HIV (PWH) (receiving tenofovir/emtricitabine or lamivudine plus dolutegravir or efavirenz) and pregnant individuals without HIV, as well as their liveborn children. Newborns were randomized to receive either zidovudine (AZT) or nevirapine (NVP) postnatal prophylaxis. Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was assessed at birth and 1, 18, 24, and 36 months of life. We fit linear mixed-effects models to evaluate the association between in utero HIV/ARV exposure and average HOMA-IR from birth through 36 months of life, adjusting for confounders. RESULTS: A total of 419 children were included (287 with in utero HIV/ARV exposure and uninfected [CHEU] and 132 without in utero HIV/ARV exposure [CHUU]). CHEU were born to older women (29.6 vs 25.3 years of age) with higher gravidity (3 vs 1). HOMA-IR was persistently higher in CHEU versus CHUU in adjusted analyses (mean difference of 0.07 in log10 HOMA-IR, P = .02) from birth through 36 months of life. Among CHEU, no differences in HOMA-IR were observed from birth through 36 months by in utero ARV exposure status or between AZT and NVP infant prophylaxis arms. CONCLUSIONS: In utero HIV/ARV exposure was associated with lower insulin sensitivity throughout the first 36 months of life, indicating persistent early life metabolic disturbances which may raise concern for poorer metabolic health later in life.
RESUMO
Aboveground Biomass (AGB) in the grassland senescence period is a key indicator for assessing grassland fire risk and autumnal pasture carrying capacity. Despite the advancement of remote sensing in rapid monitoring of AGB on a regional scale, accurately monitoring AGB during the senescence period in vast arid areas remains a major challenge. Using remote sensing, environmental data, and 356 samples of grassland senescence period AGB data, this study utilizes the Gram-Schmidt Pan Sharpening (GS) method, multivariate selection methods, and machine learning algorithms (RF, SVM, and BP_ANN) to construct a model for AGB during senescence grassland, and applies the optimal model to analyze spatio-temporal pattern changes in AGB from 2000 to 2021 in arid regions. The results indicate that the GS method effectively enhances the correlation between measured AGB and vegetation indices, reducing model error to some extent; The accuracy of grassland AGB inversion models based on a single vegetation index is low (0.03 ≤ |R| ≤ 0.63), while the RF model constructed with multiple variables selected by the Boruta algorithm is the optimal model for estimating AGB in arid regions during the senescence period (R2 = 0.71, RMSE = 519.74 kg/ha); In the span of 22 years, the annual average AGB in the senescence period of arid regions was 1413.85 kg/ha, with regions of higher AGB primarily located in the northeast and southwest of the study area. The area experiencing an increase in AGB during the senescence period (79.97 %) was significantly larger than that with decreased AGB (20.03 %).