scholarly journals Antigos e novos indicadores antropométricos como preditores de resistência à insulina em adolescentes

2014 ◽  
Vol 58 (8) ◽  
pp. 838-843 ◽  
Author(s):  
Isabella Barbosa Pereira Carneiro ◽  
Helena Alves de Carvalho Sampaio ◽  
Antônio Augusto Ferreira Carioca ◽  
Francisco José Maia Pinto ◽  
Nágila Raquel Teixeira Damasceno
Keyword(s):  
Insulin Resistance ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Model Assessment ◽  
Homeostasis Model Assessment ◽  
Receiver Operating

Objetivo Apesar da importância da resistência à insulina (RI) no desenvolvimento de doenças crônicas, seu diagnóstico envolve demandas invasivas. Assim, faz-se necessário o desenvolvimento de métodos alternativos para predizer RI na prática clínica, sendo os indicadores antropométricos uma alternativa. Portanto, o objetivo deste estudo é avaliar o comportamento desses indicadores com relação ao HOMA-IR (Homeostasis Model Assessment of Insulin Resistance). Materiais e métodos: Coletaram-se peso, altura e circunferência da cintura de 148 adolescentes. A partir destes, calcularam-se índice de massa corporal (IMC), índice de massa corporal invertido (IMCi), relação cintura-estatura (RCE) e índice de conicidade (IC). Coletaram-se ainda dados de composição corporal (percentual de gordura corporal – %GC), por meio de bioimpedância elétrica, e dados bioquímicos (glicemia e insulinemia de jejum) empregados no cálculo do HOMA-IR. O ponto de corte para o HOMA-IR adotado foi de 2,39±1,93. A análise estatística envolveu a correlação de Spearman, a construção de modelos de regressão linear múltiplos e curvas ROC (Receiver Operating Characteristic), com IC de 95%. Utilizou-se o pacote estatístico SPSS v.18.0, considerando p<0,05 como nível de significância. Resultados Todos os indicadores antropométricos estavam estatisticamente correlacionados de forma positiva ao HOMA-IR. A curva ROC mostrou que CC, RCE e IC, nesta ordem, apresentaram-se mais eficazes em predizer RI. Conclusão Entre os indicadores estudados, aqueles relacionados ao acúmulo de gordura central parecem os mais indicados para predizer RI.

scholarly journals Ponto de corte do índice Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) avaliado pela curva Receiver Operating Characteristic (ROC) na detecção de síndrome metabólica em crianças pré-púberes com excesso de peso

2008 ◽  
Vol 52 (9) ◽  
pp. 1466-1473 ◽  
Author(s):  
Isabel Rey Madeira ◽  
Cecilia N. Miranda Carvalho ◽  
Fernanda Mussi Gazolla ◽  
Haroldo José de Matos ◽  
Marcos Antonio Borges ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
International Diabetes Federation ◽  
Model Assessment ◽  
Sindrome Metabolica ◽  
Homeostatic Model Assessment ◽  
Homeostatic Model ◽  
Receiver Operating

OBJETIVO: Estabelecer, entre os pontos de corte do índice homeostatic model assessment for insulin resistance (HOMA-IR), citados na literatura, o melhor em identificar a síndrome metabólica (SM) em crianças com obesidade e sobrepeso. MÉTODOS: Foram estudadas 140 crianças pré-púberes. A definição de SM foi adaptada da International Diabetes Federation. Para cada ponto de corte de HOMA-IR foram estimados sensibilidade e especificidade, tomandose como desfecho a SM. Uma curva receiver operating characteristic (ROC) foi construída com estes valores. RESULTADOS: O grupo estudado constituiu-se de 106 crianças com obesidade (37 meninas e 69 meninos) e 34 com sobrepeso (19 meninas e 15 meninos), média de idade 6,5 ± 2,3 anos. A acurácia da curva ROC foi 72%, e o melhor ponto de corte foi 2,5, com sensibilidade 61% e especificidade 74%. CONCLUSÃO: O índice HOMA-IR pode ser útil para detectar a SM, e o ponto de corte 2,5 mostrou-se o melhor para crianças pré-púberes com obesidade e sobrepeso.

scholarly journals Calprotectin is a potential prognostic marker for polycystic ovary syndrome

2016 ◽  
Vol 54 (2) ◽  
pp. 253-257
Author(s):  
Shouzhen Chen ◽  
Mei Jiang ◽  
Tao Ding ◽  
Junmei Wang ◽  
Ping Long
Keyword(s):  
Insulin Resistance ◽  
Polycystic Ovary Syndrome ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Polycystic Ovary ◽  
Characteristic Curve ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ovary Syndrome ◽  
Inflammatory Conditions ◽  
Receiver Operating

Background Calprotectin is an antimicrobial, calcium and zinc-binding heterocomplex protein and has been proposed as a marker to rule out inflammatory conditions. The aim of this study was to evaluate the role of calprotectin in the diagnosis of polycystic ovary syndrome and to investigate the association between calprotectin and insulin resistance. Methods A total of 41 females with polycystic ovary syndrome and 54 age-matched without polycystic ovary syndrome were eligible for the study. Serum concentration of calprotectin was determined using enzyme-linked immunosorbent assay. Clinical characteristics, hormone and metabolic parameters were evaluated in each subject. The predictive value of serum calprotectin was assessed using receiver operating characteristic curves. Correlations between the serum calprotectin concentrations and insulin resistance were examined using Spearman’s correlation. Results We found that the serum calprotectin concentrations were significantly higher in polycystic ovary syndrome compared with the non-polycystic ovary syndrome group ( P < 0.001). The area under the receiver operating characteristic curve assay yielded a satisfactory result of 0.88 (95% confidence interval 0.81–0.95; P < 0.001). The optimum cut-off was 2.4  µg/mL with a 85.2% specificity and 75.6% sensitivity for polycystic ovary syndrome diagnosis. A significant positive correlation was found between the serum calprotectin and insulin resistance. Conclusions These results suggest that calprotectin might be a useful adjunct in the diagnosis of polycystic ovary syndrome, especially those with insulin resistance.

scholarly journals Association of Metabolic Syndrome with the Adiponectin to Homeostasis Model Assessment of Insulin Resistance Ratio

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yu-Song Ding ◽  
Shu-Xia Guo ◽  
Ru-Lin Ma ◽  
Shu-Gang Li ◽  
Heng Guo ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Operating Characteristic ◽  
Diagnostic Marker ◽  
Roc Curves ◽  
Model Assessment ◽  
Homeostasis Model Assessment ◽  
Middle Aged ◽  
Diagnostic Efficacy ◽  
Increased Risk

This study aimed at determining whether the adiponectin to HOMA-IR (A/H) ratio is associated with MetS and MetS components and comparing the diagnostic efficacy of adiponectin, HOMA-IR, and the A/H ratio in healthy, middle-aged participants. MetS was assessed in 1628 Kazakh participants (men, 768; women, 860). The associations between adiponectin, HOMA-IR, and the A/H ratio with the components of MetS and MetS were examined using logistic regression analysis and receiver operating characteristic (ROC) curves. Our results show that A/H ratio may be a better diagnostic marker for MetS than either HOMA-IR or adiponectin alone, and it may serve as an important biomarker to determine an increased risk for MetS in healthy middle-aged population.

scholarly journals Comparison between Surrogate Indexes of Insulin Sensitivity/Resistance and Hyperinsulinemic Euglycemic Glucose Clamps in Rhesus Monkeys

Endocrinology ◽  
2011 ◽  
Vol 152 (2) ◽  
pp. 414-423 ◽  
Author(s):  
Ho-Won Lee ◽  
Ranganath Muniyappa ◽  
Xu Yan ◽  
Lilly Q. Yue ◽  
Ellen H. Linden ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Receiver Operating Characteristic ◽  
Rhesus Monkeys ◽  
Operating Characteristic ◽  
Predictive Accuracy ◽  
Glucose Clamp ◽  
Calibration Model ◽  
Model Assessment ◽  
Characteristic Analysis ◽  
Receiver Operating

Abstract The euglycemic glucose clamp is the reference method for assessing insulin sensitivity in humans and animals. However, clamps are ill-suited for large studies because of extensive requirements for cost, time, labor, and technical expertise. Simple surrogate indexes of insulin sensitivity/resistance including quantitative insulin-sensitivity check index (QUICKI) and homeostasis model assessment (HOMA) have been developed and validated in humans. However, validation studies of QUICKI and HOMA in both rats and mice suggest that differences in metabolic physiology between rodents and humans limit their value in rodents. Rhesus monkeys are a species more similar to humans than rodents. Therefore, in the present study, we evaluated data from 199 glucose clamp studies obtained from a large cohort of 86 monkeys with a broad range of insulin sensitivity. Data were used to evaluate simple surrogate indexes of insulin sensitivity/resistance (QUICKI, HOMA, Log HOMA, 1/HOMA, and 1/Fasting insulin) with respect to linear regression, predictive accuracy using a calibration model, and diagnostic performance using receiver operating characteristic. Most surrogates had modest linear correlations with SIClamp (r ≈ 0.4–0.64) with comparable correlation coefficients. Predictive accuracy determined by calibration model analysis demonstrated better predictive accuracy of QUICKI than HOMA and Log HOMA. Receiver operating characteristic analysis showed equivalent sensitivity and specificity of most surrogate indexes to detect insulin resistance. Thus, unlike in rodents but similar to humans, surrogate indexes of insulin sensitivity/resistance including QUICKI and log HOMA may be reasonable to use in large studies of rhesus monkeys where it may be impractical to conduct glucose clamp studies.

scholarly journals Plotting receiver operating characteristic and precision-recall curves from presence and background data

2021 ◽  
Author(s):  
Wenkai Li ◽  
Qinghua Guo
Keyword(s):  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Species Distribution Models ◽  
Model Assessment ◽  
Distribution Models ◽  
New Approach ◽  
Good Ability ◽  
Background Data ◽  
Virtual Species ◽  
Receiver Operating

1. The receiver operating characteristic (ROC) and precision-recall (PR) plots have been widely used to evaluate the performances of species distribution models. Plotting ROC/PR curves requires a traditional test set with both presence and absence data (namely PA approach), but species absence data are usually not available in reality. Plotting ROC/PR curves from presence-only data while treating background data as pseudo absence data (namely PO approach) may provide misleading results. 2. In this study we propose a new approach to calibrate the ROC/PR curves from presence and background data with user-provided information on a constant c, namely PB approach. An estimate of c can also be derived from the PB-based ROC/PR plots given that a model with good ability of discrimination is available. We used three virtual species and a real aerial photography to test the effectiveness of the proposed PB-based ROC/PR plots. Different models (or classifiers) were trained from presence and background data with various samples sizes. The ROC/PR curves plotted by PA approach were used to benchmark the curves plotted by PO and PB approaches. 3. Experimental results show that the curves and areas under curves by PB approach are more similar to that by PA approach as compared with PO approach. The PB-based ROC/PR plots also provide highly accurate estimations of c in our experiment. 4. We conclude that the proposed PB-based ROC/PR plots can provide valuable complements to existing model assessment methods, and they also provide an additional way to estimate the constant c (or species prevalence) from presence and background data.

Übereinstimmung von klinischer Diagnose, strukturierten Interviews und Selbstbeurteilungsfragebögen bei Depression im Kindes- und Jugendalter

2012 ◽  
Vol 40 (6) ◽  
pp. 405-414 ◽  
Author(s):  
Kathrin Dolle ◽  
Gerd Schulte-Körne ◽  
Nikolaus von Hofacker ◽  
Yonca Izat ◽  
Antje-Kathrin Allgaier
Keyword(s):  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Kinder Und Jugendliche ◽  
Prädiktive Werte ◽  
Receiver Operating

Fragestellung: Die vorliegende Studie untersucht die Übereinstimmung von strukturierten Kind- und Elterninterviews sowie dem klinischen Urteil bei der Diagnostik depressiver Episoden im Kindes- und Jugendalter. Zudem prüft sie, ob sich die Treffsicherheit und die optimalen Cut-off-Werte von Selbstbeurteilungsfragebögen in Referenz zu diesen verschiedenen Beurteilerperspektiven unterscheiden. Methodik: Mit 81 Kindern (9–12 Jahre) und 88 Jugendlichen (13–16 Jahre), die sich in kinder- und jugendpsychiatrischen Kliniken oder Praxen vorstellten, und ihren Eltern wurden strukturierte Kinder-DIPS-Interviews durchgeführt. Die Kinder füllten das Depressions-Inventar für Kinder und Jugendliche (DIKJ) aus, die Jugendlichen die Allgemeine Depressions-Skala in der Kurzform (ADS-K). Übereinstimmungen wurden mittels Kappa-Koeffizienten ermittelt. Optimale Cut-off-Werte, Sensitivität, Spezifität sowie positive und negative prädiktive Werte wurden anhand von Receiver operating characteristic (ROC) Kurven bestimmt. Ergebnisse: Die Interviews stimmten untereinander sowie mit dem klinischen Urteil niedrig bis mäßig überein. Depressive Episoden wurden häufiger nach klinischem Urteil als in den Interviews festgestellt. Cut-off-Werte und Validitätsmaße der Selbstbeurteilungsfragebögen variierten je nach Referenzstandard mit den schlechtesten Ergebnissen für das klinische Urteil. Schlussfolgerungen: Klinische Beurteiler könnten durch den Einsatz von strukturierten Interviews profitieren. Strategien für den Umgang mit diskrepanten Kind- und Elternangaben sollten empirisch geprüft und detailliert beschrieben werden.

Use of Receiver Operating Characteristic (ROC) Curves to Evaluate Computer Confidence Threshold and Clinical Performance in the Diagnosis of Appendicitis

1978 ◽  
Vol 17 (03) ◽  
pp. 157-161 ◽  
Author(s):  
F. T. De Dombal ◽  
Jane C. Horrocks
Keyword(s):  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Clinical Performance ◽  
Roc Curves ◽  
Final Diagnosis ◽  
Confidence Threshold ◽  
Computer Aided ◽  
Computer Confidence ◽  
Overall Performance ◽  
Receiver Operating

This paper uses simple receiver operating characteristic (ROC) curves (i) to study the effect of varying computer confidence of threshold levels and (ii) to evaluate clinical performance in the diagnosis of acute appendicitis. Over 1300 patients presenting to five centres with abdominal pain of short duration were studied in varying detail. Clinical and computer-aided diagnostic predictions were compared with the »final« diagnosis. From these studies it is concluded the simplistic setting of a 50/50 confidence threshold for the computer program is as »good« as any other. The proximity of a computer-aided system changed clinical behaviour patterns; a higher overall performance level was achieved and clinicians performance levels became associated with the »mildly conservative« end of the computers ROC curve. Prior forecasts of over-confidence or ultra-caution amongst clinicians using the computer-aided system have not been fulfilled.

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