Comparing Performances of Logistic Regression, Classification & Regression Trees and Artificial Neural Networks for Predicting Albuminuria in Type 2 Diabetes Mellitus

In this study, performances of classification methods were compared in order to predict the presence of albuminuria in type 2 diabetes mellitus patients. A retrospective analysis was performed in 266 subjects. We compared performances of logistic regression (LR), classification and regression trees (C&RT) and two artificial neural networks algorithms. Predictor variables were gender, urine creatinine, weight, blood urea, serum albumin, age, creatinine clearance, fasting plasma glucose, post-prandial plasma glucose, and HbA1c. For validation set, the best classification accuracy (84.85%), sensitivity (68.0%) and the highest Youden index (0.63) was found in the MLP model but the specificity was 95.12%. Additionally, the specificity of all the models was close to each other. For whole data set the results were found as 84.21%, 53.95%, 0.50 and 96.32% respectively. Consequently, the model had the highest predictive capability to predict the presence of albuminuria was MLP. According to this model, blood urea and serum albumin were the most important variables for predicting the albuminuria. On the basis of these considerations, we suggest that data should be better explored and processed by high performance modeling methods. Researchers should avoid assessment of data by using only one method in future studies focusing on albuminuria in type 2 diabetes mellitus patients or any other clinical condition

Common Methylenetetrahydrofolate Reductase Polymorphisms (A1298C & C677T) in Ectopic Trophoblasts and Methotrexate Treatment Failure in Tubal Pregnancies

Objectives: The success rate of methotrexate (MTX) therapy varies among tubal ectopic pregnancies. Commonmethylenetetrahydrofolate reductase (MTHFR) polymorphisms (C677T&A1298C) have been suggested to alter MTX effect. This study aimed to assess and compare MTX treatment failure rates with respect to MTHFR polymorphisms in trophoblasts of ectopic tubal pregnancies.Material and methods: A retrospective chart review of tubal ectopic pregnancies was conducted and 34 eligible cases were found. Paraffinized blocks of ectopic trophoblastic tissues were retrieved from the archives of pathology department.Common MTHFR polymorphisms were studied on microdissected trophoblastic tissues. Sixteen cases with history of failed MTX therapy (study group) and 18 control cases were compared for their pertinent clinical characteristics and common MTHFR polymorphisms (C677T&A1298) data.Results: In the study group, there were 8 (50%) C677T single nucleotide polymorphisms (SNP) and 9 (56.7%) A1298C SNP. Polymorphism rates were not found to be different between two groups for neither polymorphism (p > 0.05 for both). Number of compound heterozygotes was 3 (18.7%) in study group and 5 (27.7%) in controls (p = 0.693). In addition, MTHFR polymorphism presence seemed to have no effect on interval serum β-hCG concentration change in MTX-fail group (p=0.693).Conclusions: Our data implied that common MTHFR polymorphisms of ectopic trophoblastic tissue are not associated with MTX failure in patients with tubal pregnancies. Additionally, serum β-hCG concentration changes caused by MTX treatment and studied MTHFR polymorphisms are likely independent

The Comparisons of Four Splitting Rules for Fitting a Classification Tree with Simulation and an Application Related to Albuminuria Data in Type 2 Diabetes Mellitus

The objective of this study was to compare the performances of splitting rules for predicting an ordinal response with simulation and a real data set. In the case of simulations, we compared across the methods using different sample sizes and the number of independent variables by employing the Monte Carlo simulation method. In the real data application, an analysis was performed with 265 cases. The results showed that the performances of the generalized Gini with the linear and quadratic costs of misclassification were better suited for analysis based on the gamma ordinal association measure and misclassification error rate than the other approaches. According to the gamma ordinal association measure, the generalized Gini (linear and quadratic) to the major risk factors determined for albuminuria in type 2 diabetes mellitus patients showed a slightly better performance than the other approaches. The predictive capability of splitting rules based on generalized Gini for predicting an ordinal response can be used for different sample sizes, number of independent variables and potential future suitable classification data problems. Consequently, our study will move towards choosing the generalized Gini (linear or quadratic) as the splitting rule and evaluate the data by using the Classification Trees (CT) in future studies, focusing on predicting an ordinal response

Second trimester maternal serum–amniotic fluid nitric oxide and vascular endothelial growth factor levels in relation to uterine artery Doppler indices in pregnancies with normal outcome

The aim of the present study was to explore the possible relations of maternal serum and amniotic fluid nitric oxide (NO) and of vascular endothelial growth factor A (VEGF-A) concentrations with uterine artery Doppler indices (UtADs) in a healthy second trimester obstetric population. In this regard, the levels of NO and VEGF-A were measured in maternal sera and the amniotic fluid samples were in 36 subjects who were in their early second trimester of pregnancy. The mean levels for VEGF-A were 110.3 ± 31.5 pg/ml in maternal serum and 149.6 ± 31.3 pg/ml in amniotic fluid. Mean levels for NO were 5.7 ± 4.7 µmol in maternal serum and 12.9 ± 3.4 µmol in amniotic fluid. UtADs were measured concurrently with the sample collections. The mean value for uterine artery pulsatility index (PI) was 1.3 ± 0.4. The measurements were then analysed for possible correlations, whereby no correlation was found between UtAD and maternal serum levels of either molecule (p = .828 and p = .662 for VEGF-A and NO, respectively). However, a positive correlation was found between the NO levels in the amniotic fluid compartment and UtAD (r = 0.432, p = .009 for PI). Therefore, a correlation of UtAD with amniotic fluid NO can be expected in pregnancies with a normal outcome.Impact Statement What is already known on this subject? Nitric oxide (NO) and vascular endothelial growth factor A (VEGF-A) are important vasoactive molecules that play significant roles in early angiogenesis and placentation. What the results of this study add? There is a positive correlation between the amniotic fluid NO levels and the uterine artery Doppler indices (UtADs) in the second trimester of pregnancies with normal outcomes. What the implications are of these findings for clinical practice and/or future research? A correlation between amniotic fluid NO levels and UtAD may indicate a normal trophoblastic invasion. Disturbance of this balance may be expected in certain adverse pregnancy outcomes. Additional studies are needed to further explore the molecular signs of early abnormal placentation and their clinical reflection