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Biostatistics Commons™

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University of South Carolina

2018

Articles 1 - 10 of 10

Full-Text Articles in Biostatistics

Positive Association Between Dietary Inflammatory Index And The Risk Of Osteoporosis: Results From The Koges_Health Examinee (Hexa) Cohort Study, Hye Sun Kim, Cheongmin Sohn, Minji Kwon, Woori Na, Nitin Shivappa, James R. Hébert, Mi Kyung Kim Dec 2018

Positive Association Between Dietary Inflammatory Index And The Risk Of Osteoporosis: Results From The Koges_Health Examinee (Hexa) Cohort Study, Hye Sun Kim, Cheongmin Sohn, Minji Kwon, Woori Na, Nitin Shivappa, James R. Hébert, Mi Kyung Kim

Faculty Publications

Previous studies have found that diet’s inflammatory potential is related to various diseases. However, little is known about its relationship with osteoporosis. The aim of this study was to investigate the association between the dietary inflammatory index (DII®) and osteoporosis risk in a large-scale prospective cohort study in Korea. This prospective cohort study included 159,846 participants (men 57,740; women 102,106) from South Korea with a mean follow-up of 7.9 years. The DII was calculated through a validated semi-quantitative FFQ (SQFFQ), and information on osteoporosis was self-reported by the participants. Analyses were performed by using a multivariable Cox proportional hazard model. …

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Modification Of Asphalt Rubber With Nanoclay Towards Enhanced Storage Stability, Song-Yi Park, Minji Kang, Lynne Wilkens, Yurii Shvetsov, Brook Harmon, Nitin Shivappa, Michael Wirth, James R. Hébert, Christopher Haiman, Loïc Le Marchand, Carol Boushey Oct 2018

Modification Of Asphalt Rubber With Nanoclay Towards Enhanced Storage Stability, Song-Yi Park, Minji Kang, Lynne Wilkens, Yurii Shvetsov, Brook Harmon, Nitin Shivappa, Michael Wirth, James R. Hébert, Christopher Haiman, Loïc Le Marchand, Carol Boushey

Faculty Publications

Asphalt rubber (AR), which is prepared by blending crumb rubber and bitumen, provides various advantages, including superior rutting resistance, lower road-tire noise and longer service life. However, contractors have expressed concerns regarding its poor storage stability, which in turn limits its wider application. This study aims to address the storage stability concern by incorporating nano-montmorillonite (nanoclay). Three types of nanoclay were dispersed into hot AR binder by high shear blending. The rheological properties of nanoclay-crumb rubber modifier (CRM)-modified bitumen were evaluated through Superpave performance grade (PG) tests and the storage stability was characterized by measuring the difference in softening points …

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Dietary Inflammatory Index And Biomarkers Of Lipoprotein Metabolism, Inflammation And Glucose Homeostasis In Adults, Catherine Phillips, Nitin Shivappa, James R. Hébert, Ivan Perry Aug 2018

Dietary Inflammatory Index And Biomarkers Of Lipoprotein Metabolism, Inflammation And Glucose Homeostasis In Adults, Catherine Phillips, Nitin Shivappa, James R. Hébert, Ivan Perry

Faculty Publications

Accumulating evidence identifies diet and inflammation as potential mechanisms contributing to cardiometabolic risk. However, inconsistent reports regarding dietary inflammatory potential, biomarkers of cardiometabolic health and metabolic syndrome (MetS) risk exist. Our objective was to examine the relationships between a food frequency questionnaire (FFQ)-derived dietary inflammatory index (DII®), biomarkers of lipoprotein metabolism, inflammation and glucose homeostasis and MetS risk in a cross-sectional sample of 1992 adults. Energy-adjusted DII (E-DII) scores derived from an FFQ were calculated. Lipoprotein particle size and subclass concentrations were measured using nuclear magnetic resonance (NMR) spectroscopy. Serum acute-phase reactants, adipocytokines, pro-inflammatory cytokines and white blood cell (WBC) …

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Design, Development And Construct Validation Of The Children’S Dietary Inflammatory Index, Samira Khan, Micheal D. Wirth, Andrew Ortaglia, Christian R. Alvarado, Nitin Shivappa, Thomas Hurley, James R. Hébert Jul 2018

Design, Development And Construct Validation Of The Children’S Dietary Inflammatory Index, Samira Khan, Micheal D. Wirth, Andrew Ortaglia, Christian R. Alvarado, Nitin Shivappa, Thomas Hurley, James R. Hébert

Faculty Publications

Objective: To design and validate a literature-derived, population-based Children’s Dietary Inflammatory Index (C-DII)TM. Design: The C-DII was developed based on a review of literature through 2010. Dietary data obtained from children in 16 different countries were used to create a reference database for computing C-DII scores based on consumption of macronutrients, vitamins, minerals, and whole foods. Construct validation was performed using quantile regression to assess the association between C-reactive protein (CRP) concentrations and C-DII scores. Data Sources: All data used for construct validation were obtained from children between six and 14 years of age (n = 3300) who participated in …

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Dietary Inflammatory Index And Type 2 Diabetes Mellitus In Adults: The Diabetes Mellitus Survey Of Mexico City, Edgar Denova-Gutiérrez, Paloma Muñoz-Aguirre, Nitin Shivappa, James R. Hébert, Lizbeth Tolentino-Mayo, Carolina Batis, Simón Barquera Mar 2018

Dietary Inflammatory Index And Type 2 Diabetes Mellitus In Adults: The Diabetes Mellitus Survey Of Mexico City, Edgar Denova-Gutiérrez, Paloma Muñoz-Aguirre, Nitin Shivappa, James R. Hébert, Lizbeth Tolentino-Mayo, Carolina Batis, Simón Barquera

Faculty Publications

Diet and inflammation are both associated with type 2 diabetes mellitus (T2DM). In the present study, we aimed to assess the relation between the dietary inflammatory index (DII) and the presence of T2DM in Mexican adults participating in the Diabetes Mellitus Survey administered in Mexico City (DMS-MC). The study involved 1174 subjects (48.5% men) between 20–69 years of age. A validated semi-quantitative food frequency questionnaire was employed to evaluate dietary intake and to compute DII. The DII is based on scientific evidence about the association between dietary compounds and six established inflammatory biomarkers. Multivariate logistic regression models were used to …

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Dietary Inflammatory Index And Cardiovascular Risk And Mortality—A Meta-Analysis, Nitin Shivappa, Justyna Godos, James R. Hébert, Michael Wirth, Gabriele Piuri, Attilio Speciani, Giuseppe Grosso Feb 2018

Dietary Inflammatory Index And Cardiovascular Risk And Mortality—A Meta-Analysis, Nitin Shivappa, Justyna Godos, James R. Hébert, Michael Wirth, Gabriele Piuri, Attilio Speciani, Giuseppe Grosso

Faculty Publications

Diet and chronic inflammation have been suggested to be risk factors in the development of cardiovascular disease (CVD) and related mortality. The possible link between the inflammatory potential of diet measured through the Dietary Inflammatory Index (DII®) and CVD has been investigated in several populations across the world. The aim of this study was to conduct a meta-analysis on studies exploring this association. Data from 14 studies were eligible, of which two were case-control, eleven were cohort, and one was cross-sectional. Results from the random-effects meta-analysis showed a positive association between increasing DII, indicating a pro-inflammatory diet, and …

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Lower Dietary Inflammatory Index Scores Are Associated With Lower Glycemic Index Scores Among College Students, Yeonsoo Kim, Jie Chen, Michael Wirth, Nitin Shivappa, James R. Hébert Feb 2018

Lower Dietary Inflammatory Index Scores Are Associated With Lower Glycemic Index Scores Among College Students, Yeonsoo Kim, Jie Chen, Michael Wirth, Nitin Shivappa, James R. Hébert

Faculty Publications

The association between the Dietary Inflammatory Index (DII®), the glycemic index (GI), and the glycemic load (GL) is not known, although it is known that carbohydrates are pro-inflammatory. We aimed to measure the association between the DII and both GI and GL among college students. In this cross-sectional study, 110 college students completed a 3-day food diary, which was used to calculate the DII, the GI, the GL, and the healthy eating index (HEI)-2010. Least square means and 95% confidence intervals of the GI, the GL, and the HEI-2010 were presented per DII tertile using generalized linear mixed …

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Adjusting For Mis-Reporting In Count Data, Gelareh Rahimighazikalayeh Jan 2018

Adjusting For Mis-Reporting In Count Data, Gelareh Rahimighazikalayeh

Theses and Dissertations

Any counting system is prone to recording errors including underreporting and overreporting. Ignoring the misreporting pattern in count data can give rise to bias in the estimation of model parameters. Accordingly, Poisson, negative binomial and generalized Poisson regression have been expanded in some instances to capture reporting biases. However, to our knowledge, no program has been developed to allow users to apply all of these models when needed. In the first part of the dissertation, we review the available models for underreported counts and develop a Stata command to estimate Poisson, negative binomial and generalized Poisson regression models for underreported …

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Estimation Procedures For Complex Survival Models And Their Applications In Epidemiology Studies, Jie Zhou Jan 2018

Estimation Procedures For Complex Survival Models And Their Applications In Epidemiology Studies, Jie Zhou

Theses and Dissertations

In this dissertation, we aim to address three important questions in practice, which can be solved through complex survival models. The first project focuses on studying the longitudinal fitness effect on cardiovascular disease (CVD) mortality. In the second project, we study the disease-death relation between CVD and all-cause mortality and evaluate important covariate effects on the disease or death transitions. In the third project, we compare antiretroviral treatment (ART) for HIV patients and consider both treatment effect and side effect of the drugs. The first two projects are motivated by the Aerobics Center Longitudinal Study (ACLS) datasets and the third …

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Comparison Of The Performance Of Simple Linear Regression And Quantile Regression With Non-Normal Data: A Simulation Study, Marjorie Howard Jan 2018

Comparison Of The Performance Of Simple Linear Regression And Quantile Regression With Non-Normal Data: A Simulation Study, Marjorie Howard

Theses and Dissertations

Linear regression is a widely used method for analysis that is well understood across a wide variety of disciplines. In order to use linear regression, a number of assumptions must be met. These assumptions, specifically normality and homoscedasticity of the error distribution can at best be met only approximately with real data. Quantile regression requires fewer assumptions, which offers a potential advantage over linear regression. In this simulation study, we compare the performance of linear (least squares) regression to quantile regression when these assumptions are violated, in order to investigate under what conditions quantile regression becomes the more advantageous method …

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