scholarly journals Longitudinal changes in telomere length in PCB-exposed individuals: interaction with CMV infection

2021 ◽  
Vol 95 (4) ◽  
pp. 1517-1520
Author(s):  
Fabian Beier ◽  
Andre Esser ◽  
Lucia Vankann ◽  
Anne Abels ◽  
Thomas Schettgen ◽  
...  
Keyword(s):  
Immune System ◽  
Telomere Length ◽  
Mixed Effects ◽  
Analysis Of Covariance ◽  
Mixed Effects Models ◽  
Immune Senescence ◽  
Cmv Infection ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects

AbstractWe recently demonstrated a significant shortening of age-adapted telomere length (TL) in lymphocytes of polychlorinated biphenyls (PCB)-exposed individuals. Here, we analyzed TL in individuals of the same PCB-exposed cohort during a 6-year follow-up period, investigating the change in TL between the first and second measurement as a function of time, concentration of PCBs and cytomegalovirus (CMV) infection. The age-adjusted TL of lymphocytes within the cohort of PCB-exposed individuals recovered from a first assessment in 2011 to a second assessment in 2017. Remarkably, if the concentration of lower chlorinated PCBs (LC PCBs) in 2011 was high (≥ 0.055 µg/L), the TL of CMV seropositive individuals remained significantly shortened both compared to age-adjusted controls as well as intra individually. This was confirmed by analysis of covariance as well as by multivariate linear mixed effects models. Since telomeres are responsive to various stress response pathways, including viral infection, we conclude that PCBs could contribute to immune senescence-like phenotypes associated with CMV infections and exacerbate negative aspects associated with the aging of the immune system.

scholarly journals Change in Dyslipidemia with Declining Glomerular Filtration Rate and Increasing Proteinuria in Children with CKD

2019 ◽  
Vol 14 (12) ◽  
pp. 1711-1718 ◽  
Author(s):  
Jeffrey M. Saland ◽  
Juan C. Kupferman ◽  
Christopher B. Pierce ◽  
Joseph T. Flynn ◽  
Mark M. Mitsnefes ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Filtration Rate ◽  
Hdl Cholesterol ◽  
Mixed Effects ◽  
Mixed Effects Models ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Changes Over Time ◽  
Over Time

Background and objectivesDyslipidemia, a risk factor for cardiovascular disease, is common in CKD but its change over time and how that change is influenced by concurrent progression of CKD have not been previously described.Design, setting, participants, & measurementsIn the CKD in Children study we prospectively followed children with progressive CKD and utilized multivariable, linear mixed-effects models to quantify the longitudinal relationship between within-subject changes in lipid measures (HDL cholesterol, non-HDL cholesterol, triglycerides) and within-subject changes in GFR, proteinuria, and body mass index (BMI).ResultsA total of 508 children (76% nonglomerular CKD, 24% glomerular CKD) had 2–6 lipid measurements each, with a median follow-up time of 4 (interquartile range [IQR], 2.1–6.0) years. Among children with nonglomerular CKD, dyslipidemia was common at baseline (35%) and increased significantly as children aged; 43% of children with glomerular CKD had dyslipidemia at baseline and demonstrated persistent levels as they aged. Longitudinal increases in proteinuria were independently associated with significant concomitant increases in non-HDL cholesterol (nonglomerular: 4.9 [IQR, 3.4–6.4] mg/dl; glomerular: 8.5 [IQR, 6.0–11.1] mg/dl) and triglycerides (nonglomerular: 3% [IQR, 0.8%–6%]; glomerular: 5% [IQR, 0.6%–9%]). Decreases in GFR over follow-up were significantly associated with concomitant decreases of HDL cholesterol in children with nonglomerular CKD (−1.2 mg/dl; IQR, −2.1 to −0.4 mg/dl) and increases of non-HDL cholesterol in children with glomerular CKD (3.9 mg/dl; IQR, 1.4–6.5 mg/dl). The effects of increased BMI also affected multiple lipid changes over time. Collectively, glomerular CKD displayed stronger, deleterious associations between within-subject change in non-HDL cholesterol (9 mg/dl versus 1.2 mg/dl; P<0.001) and triglycerides (14% versus 3%; P=0.004), and within-subject change in BMI; similar but quantitatively smaller differences between the two types of CKD were noted for associations of within-subject change in lipids to within-subject change in GFR and proteinuria.ConclusionsDyslipidemia is a common and persistent complication in children with CKD and it worsens in proportion to declining GFR, worsening proteinuria, and increasing BMI.

The Use of Theory of Linear Mixed-Effects Models to Detect Fraudulent Erasures at an Aggregate Level

2021 ◽  
pp. 001316442199489
Author(s):  
Luyao Peng ◽  
Sandip Sinharay
Keyword(s):  
Type I Error ◽  
Real Data ◽  
Mixed Effects ◽  
Error Rates ◽  
Mixed Effects Models ◽  
Type I ◽  
Aggregate Level ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Best Linear Unbiased

Wollack et al. (2015) suggested the erasure detection index (EDI) for detecting fraudulent erasures for individual examinees. Wollack and Eckerly (2017) and Sinharay (2018) extended the index of Wollack et al. (2015) to suggest three EDIs for detecting fraudulent erasures at the aggregate or group level. This article follows up on the research of Wollack and Eckerly (2017) and Sinharay (2018) and suggests a new aggregate-level EDI by incorporating the empirical best linear unbiased predictor from the literature of linear mixed-effects models (e.g., McCulloch et al., 2008). A simulation study shows that the new EDI has larger power than the indices of Wollack and Eckerly (2017) and Sinharay (2018). In addition, the new index has satisfactory Type I error rates. A real data example is also included.

scholarly journals Association of body condition with lameness in dairy cattle: a single-farm longitudinal study

2021 ◽  
pp. 1-4
Author(s):  
Michaela Kranepuhl ◽  
Detlef May ◽  
Edna Hillmann ◽  
Lorenz Gygax
Keyword(s):  
Body Condition ◽  
Body Condition Score ◽  
Mixed Effects ◽  
Mixed Effects Models ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Confounding Variables ◽  
Condition Score ◽  
The Impact ◽  
The Relationship

Abstract This research communication describes the relationship between the occurrence of lameness and body condition score (BCS) in a sample of 288 cows from a single farm that were repeatedly scored in the course of 9 months while controlling for confounding variables. The relationship between BCS and lameness was evaluated using generalised linear mixed-effects models. It was found that the proportion of lame cows was higher with decreasing but also with increasing BCS, increased with lactation number and decreased with time since the last claw trimming. This is likely to reflect the importance of sufficient body condition in the prevention of lameness but also raises the question of the impact of overcondition on lameness and the influence of claw trimming events on the assessment of lameness. A stronger focus on BCS might allow improved management of lameness that is still one of the major problems in housed cows.

D-optimal cohort designs for linear mixed-effects models

2007 ◽  
Vol 27 (14) ◽  
pp. 2586-2600 ◽  
Author(s):  
Fetene B. Tekle ◽  
Frans E. S. Tan ◽  
Martijn P. F. Berger
Keyword(s):  
Mixed Effects ◽  
Mixed Effects Models ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects
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