1. |
- Kanoni, Stavroula, et al.
(author)
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Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis.
- 2022
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In: Genome biology. - : Springer Science and Business Media LLC. - 1474-760X .- 1465-6906 .- 1474-7596. ; 23:1
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Journal article (peer-reviewed)abstract
- Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery.To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N=1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3-5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism.Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.
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2. |
- Lönnrot, Maria, et al.
(author)
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Gastrointestinal Infections Modulate the Risk for Insulin Autoantibodies as the First-Appearing Autoantibody in the TEDDY Study
- 2023
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In: Diabetes Care. - 1935-5548. ; 46:11, s. 1908-1915
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To investigate gastrointestinal infection episodes (GIEs) in relation to the appearance of islet autoantibodies in The Environmental Determinants of Diabetes in the Young (TEDDY) cohort.RESEARCH DESIGN AND METHODS: GIEs on risk of autoantibodies against either insulin (IAA) or GAD (GADA) as the first-appearing autoantibody were assessed in a 10-year follow-up of 7,867 children. Stool virome was characterized in a nested case-control study.RESULTS: GIE reports (odds ratio [OR] 2.17 [95% CI 1.39-3.39]) as well as Norwalk viruses found in stool (OR 5.69 [1.36-23.7]) at <1 year of age were associated with an increased IAA risk at 2-4 years of age. GIEs reported at age 1 to <2 years correlated with a lower risk of IAA up to 10 years of age (OR 0.48 [0.35-0.68]). GIE reports at any other age were associated with an increase in IAA risk (OR 2.04 for IAA when GIE was observed 12-23 months prior [1.41-2.96]). Impacts on GADA risk were limited to GIEs <6 months prior to autoantibody development in children <4 years of age (OR 2.16 [1.54-3.02]).CONCLUSIONS: Bidirectional associations were observed. GIEs were associated with increased IAA risk when reported before 1 year of age or 12-23 months prior to IAA. Norwalk virus was identified as one possible candidate factor. GIEs reported during the 2nd year of life were associated with a decreased IAA risk.
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3. |
- Pearce, Neil E, et al.
(author)
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IARC Monographs : 40 Years of Evaluating Carcinogenic Hazards to Humans
- 2015
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In: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 123:6, s. 507-514
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Journal article (peer-reviewed)abstract
- BACKGROUND: Recently the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also the approach used to perform these evaluations. Some critics have claimed that IARC Working Groups' failures to recognize study weaknesses and biases of Working Group members have led to inappropriate classification of a number of agents as carcinogenic to humans.OBJECTIVES: The authors of this paper are scientists from various disciplines relevant to the identification and hazard evaluation of human carcinogens. We have examined here criticisms of the IARC classification process to determine the validity of these concerns. We review the history of IARC evaluations and describe how the IARC evaluations are performed.DISCUSSION: We conclude that these recent criticisms are unconvincing. The procedures employed by IARC to assemble Working Groups of scientists from the various discipline and the techniques followed to review the literature and perform hazard assessment of various agents provide a balanced evaluation and an appropriate indication of the weight of the evidence. Some disagreement by individual scientists to some evaluations is not evidence of process failure. The review process has been modified over time and will undoubtedly be altered in the future to improve the process. Any process can in theory be improved, and we would support continued review and improvement of the IARC processes. This does not mean, however, that the current procedures are flawed.CONCLUSIONS: The IARC Monographs have made, and continue to make, major contributions to the scientific underpinning for societal actions to improve the public's health.
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4. |
- Vehik, Kendra, et al.
(author)
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Prospective virome analyses in young children at increased genetic risk for type 1 diabetes
- 2019
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In: Nature Medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 25:12, s. 1865-1872
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Journal article (peer-reviewed)abstract
- Viruses are implicated in autoimmune destruction of pancreatic islet β cells, which results in insulin deficiency and type 1 diabetes (T1D)1-4. Certain enteroviruses can infect β cells in vitro5, have been detected in the pancreatic islets of patients with T1D6 and have shown an association with T1D in meta-analyses4. However, establishing consistency in findings across studies has proven difficult. Obstacles to convincingly linking RNA viruses to islet autoimmunity may be attributed to rapid viral mutation rates, the cyclical periodicity of viruses7 and the selection of variants with altered pathogenicity and ability to spread in populations. β cells strongly express cell-surface coxsackie and adenovirus receptor (CXADR) genes, which can facilitate enterovirus infection8. Studies of human pancreata and cultured islets have shown significant variation in enteroviral virulence to β cells between serotypes and within the same serotype9,10. In this large-scale study of known eukaryotic DNA and RNA viruses in stools from children, we evaluated fecally shed viruses in relation to islet autoimmunity and T1D. This study showed that prolonged enterovirus B rather than independent, short-duration enterovirus B infections may be involved in the development of islet autoimmunity, but not T1D, in some young children. Furthermore, we found that fewer early-life human mastadenovirus C infections, as well as CXADR rs6517774, independently correlated with islet autoimmunity.
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5. |
- Driscoll, Kimberly A., et al.
(author)
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SAI-CH-6 : Development of a Short Form of the State Anxiety Inventory for Children At-Risk for Type 1 Diabetes
- 2023
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In: Journal of Pediatric Psychology. - 0146-8693. ; 48:10, s. 861-869
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Journal article (peer-reviewed)abstract
- Objective: To develop a reliable and valid short form of the State Anxiety Subscale of the State-Trait Anxiety Inventory for Children (STAI-CH) in the Environmental Determinants of Diabetes in the Young (TEDDY) study. Methods: A Development Sample of 842 10-year-old TEDDY children completed the STAI-CH State Subscale about their type 1 diabetes (T1D) risk. The best 6 items (three anxiety-present and three anxiety-absent) for use in a short form (SAI-CH-6) were identified via item-total correlations. SAI-CH-6 reliability was examined in a Validation Sample (n = 257) of children who completed the full 20-item STAI-CH State Subscale and then again in an Application Sample (n = 2,710) who completed only the SAI-CH-6. Expected associations between the children's SAI-CH-6 scores and country of residence, sex, T1D family history, accuracy of T1D risk perception, worry about getting T1D, and their parents' anxiety scores were examined. Results: The SAI-CH-6 was reliable (α = 0.81-0.87) and highly correlated with the full 20-item STAI-CH State Subscale (Development Sample: r = 0.94; Validation Sample: r = 0.92). SAI-CH-6 scores detected significant differences in state anxiety symptoms associated with T1D risk by country, T1D family history, accuracy of T1D risk perception, and worry about getting T1D and were correlated with the child's parent's anxiety. Conclusion: The SAI-CH-6 appears useful for assessing children's state anxiety symptoms when burden and time limitations prohibit the use of the STAI-CH. The utility of the SAI-CH-6 in older children with and without chronic conditions needs to be assessed.
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6. |
- Elding Larsson, Helena, et al.
(author)
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Pandemrix® vaccination is not associated with increased risk of islet autoimmunity or type 1 diabetes in the TEDDY study children
- 2018
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In: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 61:1, s. 193-202
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Journal article (peer-reviewed)abstract
- Aims/hypothesis: During the A/H1N1 2009 (A/California/04/2009) pandemic, mass vaccination with a squalene-containing vaccine, Pandemrix®, was performed in Sweden and Finland. The vaccination was found to cause narcolepsy in children and young adults with the HLA-DQ 6.2 haplotype. The aim of this study was to investigate if exposure to Pandemrix® similarly increased the risk of islet autoimmunity or type 1 diabetes. Methods: In The Environmental Determinants of Diabetes in the Young (TEDDY) study, children are followed prospectively for the development of islet autoimmunity and type 1 diabetes. In October 2009, when the mass vaccination began, 3401 children at risk for islet autoimmunity and type 1 diabetes were followed in Sweden and Finland. Vaccinations were recorded and autoantibodies against insulin, GAD65 and insulinoma-associated protein 2 were ascertained quarterly before the age of 4 years and semi-annually thereafter. Results: By 5 August 2010, 2413 of the 3401 (71%) children observed as at risk for an islet autoantibody or type 1 diabetes on 1 October 2009 had been vaccinated with Pandemrix®. By 31 July 2016, 232 children had at least one islet autoantibody before 10 years of age, 148 had multiple islet autoantibodies and 96 had developed type 1 diabetes. The risk of islet autoimmunity was not increased among vaccinated children. The HR (95% CI) for the appearance of at least one islet autoantibody was 0.75 (0.55, 1.03), at least two autoantibodies was 0.85 (0.57, 1.26) and type 1 diabetes was 0.67 (0.42, 1.07). In Finland, but not in Sweden, vaccinated children had a lower risk of islet autoimmunity (0.47 [0.29, 0.75]), multiple autoantibodies (0.50 [0.28, 0.90]) and type 1 diabetes (0.38 [0.20, 0.72]) compared with those who did not receive Pandemrix®. The analyses were adjusted for confounding factors. Conclusions/interpretation: Children with an increased genetic risk for type 1 diabetes who received the Pandemrix® vaccine during the A/H1N1 2009 pandemic had no increased risk of islet autoimmunity, multiple islet autoantibodies or type 1 diabetes. In Finland, the vaccine was associated with a reduced risk of islet autoimmunity and type 1 diabetes.
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7. |
- Haghighi, Mona, et al.
(author)
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A Comparison of Rule-based Analysis with Regression Methods in Understanding the Risk Factors for Study Withdrawal in a Pediatric Study
- 2016
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Journal article (peer-reviewed)abstract
- Regression models are extensively used in many epidemiological studies to understand the linkage between specific outcomes of interest and their risk factors. However, regression models in general examine the average effects of the risk factors and ignore subgroups with different risk profiles. As a result, interventions are often geared towards the average member of the population, without consideration of the special health needs of different subgroups within the population. This paper demonstrates the value of using rule-based analysis methods that can identify subgroups with heterogeneous risk profiles in a population without imposing assumptions on the subgroups or method. The rules define the risk pattern of subsets of individuals by not only considering the interactions between the risk factors but also their ranges. We compared the rule-based analysis results with the results from a logistic regression model in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Both methods detected a similar suite of risk factors, but the rule-based analysis was superior at detecting multiple interactions between the risk factors that characterize the subgroups. A further investigation of the particular characteristics of each subgroup may detect the special health needs of the subgroup and lead to tailored interventions.
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8. |
- Jensen, Richard A., et al.
(author)
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Multiple factors affect the loss of measurable C-peptide over 6 years in newly diagnosed 15- to 35-year-old diabetic subjects
- 2007
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In: Journal of diabetes and its complications. - : Elsevier BV. - 1056-8727 .- 1873-460X. ; 21:4, s. 205-213
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Journal article (peer-reviewed)abstract
- Objective: The aim of this study is to identify risk factors for the loss of measurable plasma C-peptide in newly diagnosed 15- to 35-year-old diabetic subjects. Methods: This Swedish study included 778 subjects. C-peptide levels were obtained each year for 6 years after diagnosis. Loss of measurable C-peptide was defined as a level at or below the lower detection limit of the local assay (0.13 nmol/l). In addition to C-peptide, other baseline covariates included gender, age, body mass index, HLA genotype, and autoantibody levels. Results: Compared with autoantibody-negative subjects, autoantibody-positive subjects had lower median baseline C-peptide (0.27 vs. 0.50, P<001), their levels declined over the study period, and the risk of losing measurable C-peptide was significantly higher when more than one autoantibody was present [odds ratio (OR), 4.0; 95% confidence interval (CI), 2.13-7.54]. Among autoantibody-positive individuals, the presence of GAD65Ab (OR, 1.8; 95% Cl, 1.24-2.51) and islet cell antibodies (OR, 1.6; 95% CI, 1.19-2.18) conferred a higher risk for loss of measurable C-peptide as did female gender (OR, 1.6; 95% CI, 1.17-2.11) and time after diagnosis (OR, 1.5 for each additional year postdiagnosis; 95% CI, 1.41-1.57). Higher baseline C-peptide levels were protective (OR, 0.5 for each additional log nanomoles per liter; 95% CI, 0.36-0.58). Conclusions: This study identified autoantibody status, gender, and baseline C-peptide levels as factors that will be useful for predicting the disease course of 15- to 35-year-old diabetic individuals.
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9. |
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10. |
- Johnson, Suzanne Bennett, et al.
(author)
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First-appearing islet autoantibodies for type 1 diabetes in young children : maternal life events during pregnancy and the child's genetic risk
- 2021
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In: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 64:3, s. 591-602
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Journal article (peer-reviewed)abstract
- AIMS/HYPOTHESIS: Psychological stress has long been considered a possible trigger of type 1 diabetes, although prospective studies examining the link between psychological stress or life events during pregnancy and the child's type 1 diabetes risk are rare. The objective of this study was to examine the association between life events during pregnancy and first-appearing islet autoantibodies (IA) in young children, conditioned by the child's type 1 diabetes-related genetic risk.METHODS: The IA status of 7317 genetically at-risk The Environmental Determinants of Diabetes in the Young (TEDDY) participants was assessed every 3 months from 3 months to 4 years, and bi-annually thereafter. Reports of major life events during pregnancy were collected at study inception when the child was 3 months of age and placed into one of six categories. Life events during pregnancy were examined for association with first-appearing insulin (IAA) (N = 222) or GAD (GADA) (N = 209) autoantibodies in the child until 6 years of age using proportional hazard models. Relative excess risk due to interaction (RERI) by the child's HLA-DR and SNP profile was estimated.RESULTS: Overall, 65% of mothers reported a life event during pregnancy; disease/injury (25%), serious interpersonal (28%) and job-related (25%) life events were most common. The association of life events during pregnancy differed between IAA and GADA as the first-appearing autoantibody. Serious interpersonal life events correlated with increased risk of GADA-first only in HLA-DR3 children with the BACH2-T allele (HR 2.28, p < 0.0001), an additive interaction (RERI 1.87, p = 0.0004). Job-related life events were also associated with increased risk of GADA-first among HLA-DR3/4 children (HR 1.53, p = 0.04) independent of serious interpersonal life events (HR 1.90, p = 0.002), an additive interaction (RERI 1.19, p = 0.004). Job-related life events correlated with reduced risk of IAA-first (HR 0.55, p = 0.004), particularly in children with the BTNL2-GG allele (HR 0.48; 95% CI 0.31, 0.76).CONCLUSIONS/INTERPRETATION: Specific life events during pregnancy are differentially related to IAA vs GADA as first-appearing IA and interact with different HLA and non-HLA genetic factors, supporting the concept of different endotypes underlying type 1 diabetes. However, the mechanisms underlying these associations remain to be discovered. Life events may be markers for other yet-to-be-identified factors important to the development of first-appearing IA.
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11. |
- Johnson, Suzanne Bennett, et al.
(author)
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Predicting Later Study Withdrawal in Participants Active in a Longitudinal Birth Cohort Study for 1 Year: The TEDDY Study.
- 2016
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In: Journal of Pediatric Psychology. - : Oxford University Press (OUP). - 1465-735X .- 0146-8693. ; 41:3, s. 373-383
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Journal article (peer-reviewed)abstract
- OBJECTIVE : To identify predictors of later study withdrawal among participants active in The Environmental Determinants of Diabetes in the Young (TEDDY) for 1 year. METHODS : Multiple logistic regression was used to discriminate 3,042 children active in TEDDY for the first 3 years from 432 children who withdrew in Years 2 or 3. Predictor variables were tested in blocks-demographic, maternal lifestyle behaviors, stress and child illness, maternal reactions to child's increased diabetes risk, in-study behaviors-and a final best model developed. RESULTS : Few demographic factors predicted study withdrawal. Maternal lifestyle behaviors, accuracy of the mother's risk perception, and in-study behaviors were more important. Frequent child illnesses were associated with greater study retention. CONCLUSIONS : Demographic measures are insufficient predictors of later study withdrawal among those active in a study for at least 1 year; behavioral/psychological factors offer improved prediction and guidance for the development of retention strategies.
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12. |
- Kemppainen, Kaisa M, et al.
(author)
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Association Between Early-Life Antibiotic Use and the Risk of Islet or Celiac Disease Autoimmunity
- 2017
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In: JAMA Pediatrics. - : American Medical Association (AMA). - 2168-6211 .- 2168-6203. ; 171:12, s. 1217-1225
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Journal article (peer-reviewed)abstract
- Importance: Evidence is lacking regarding the consequences of antibiotic use in early life and the risk of certain autoimmune diseases.Objective: To test the association between early-life antibiotic use and islet or celiac disease (CD) autoimmunity in genetically at-risk children prospectively followed up for type 1 diabetes (T1D) or CD.Design, Setting, and Participants: HLA-genotyped newborns from Finland, Germany, Sweden, and the United States were enrolled in the prospective birth cohort of The Environmental Determinants of Diabetes in the Young (TEDDY) study between November 20, 2004, and July 8, 2010. The dates of analysis were November 20, 2004, to August 31, 2014. Individuals from the general population and those having a first-degree relative with T1D were enrolled if they had 1 of 9 HLA genotypes associated with a risk for T1D.Exposures: Parental reports of the most common antibiotics (cephalosporins, penicillins, and macrolides) used between age 3 months and age 4 years were recorded prospectively.Main Outcomes and Measures: Islet autoimmunity and CD autoimmunity were defined as being positive for islet or tissue transglutaminase autoantibodies at 2 consecutive clinic visits at least 3 months apart. Hazard ratios and 95% CIs calculated from Cox proportional hazards regression models were used to assess the relationship between antibiotic use in early life before seroconversion and the development of autoimmunity.Results: Participants were 8495 children (49.0% female) and 6558 children (48.7% female) enrolled in the TEDDY study who were tested for islet and tissue transglutaminase autoantibodies, respectively. Exposure to and frequency of use of any antibiotic assessed in this study in early life or before seroconversion did not influence the risk of developing islet autoimmunity or CD autoimmunity. Cumulative use of any antibiotic during the first 4 years of life was not associated with the appearance of any autoantibody (hazard ratio [HR], 0.98; 95% CI, 0.95-1.01), multiple islet autoantibodies (HR, 0.99; 95% CI, 0.95-1.03), or the transglutaminase autoantibody (HR, 1.00; 95% CI, 0.98-1.02).Conclusions and Relevance: The use of the most prescribed antibiotics during the first 4 years of life, regardless of geographic region, was not associated with the development of autoimmunity for T1D or CD. These results suggest that a risk of islet or tissue transglutaminase autoimmunity need not influence the recommendations for clinical use of antibiotics in young children at risk for T1D or CD.
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13. |
- Kemppainen, Kaisa M, et al.
(author)
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Factors That Increase Risk of Celiac Disease Autoimmunity After a Gastrointestinal Infection in Early Life
- 2017
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In: Clinical Gastroenterology and Hepatology. - : Elsevier BV. - 1542-3565. ; 15:5, s. 5-702
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Journal article (peer-reviewed)abstract
- Background & Aims: Little is known about the pathogenic mechanisms of gluten immunogenicity in patients with celiac disease. We studied temporal associations between infections and the development of celiac disease autoimmunity, and examined effects of HLA alleles, rotavirus vaccination status, and infant feeding. Methods: We monitored 6327 children in the United States and Europe carrying HLA risk genotypes for celiac disease from 1 to 4 years of age for presence of tissue transglutaminase autoantibodies (the definition of celiac disease autoimmunity), until March 31, 2015. Parental reports of gastrointestinal and respiratory infections were collected every third month from birth. We analyzed time-varying relationships among reported infections, rotavirus vaccination status, time to first introduction of gluten, breastfeeding, and risk of celiac disease autoimmunity using proportional hazard models. Results: We identified 13,881 gastrointestinal infectious episodes (GIE) and 79,816 respiratory infectious episodes. During the follow-up period, 732 of 6327 (11.6%) children developed celiac disease autoimmunity. A GIE increased the risk of celiac disease autoimmunity within the following 3 months by 33% (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.11-1.59). This risk increased 2-fold among children born in winter and introduced to gluten before age 6 months (HR, 2.08; 95% CI, 1.46-2.98), and increased 10-fold among children without HLA-DQ2 alleles and breastfed for fewer than 4 months (HR, 9.76; 95% CI, 3.87-24.8). Risk of celiac disease autoimmunity was reduced in children vaccinated against rotavirus and introduced to gluten before age 6 months (HR, 0.57; 95% CI, 0.36-0.88). Conclusions: Gastrointestinal infections increase the risk of celiac disease autoimmunity in children with genetic susceptibility to this autoimmune disorder. The risk is modified by HLA genotype, infant gluten consumption, breastfeeding, and rotavirus vaccination, indicating complex interactions among infections, genetic factors, and diet in the etiology of celiac disease in early childhood.
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14. |
- Krause, Stephanie, et al.
(author)
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GAD Autoantibody Affinity in Adult Patients With Latent Autoimmune Diabetes, the Study Participants of a GAD65 Vaccination Trial
- 2014
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In: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 37:6, s. 1675-1680
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Journal article (peer-reviewed)abstract
- OBJECTIVE Patients with latent autoimmune diabetes in adults (LADA) express autoantibodies against the 65-kDa isoform of GAD (GADA). Intervention with recombinant human GAD65 formulated with aluminium hydroxide (GAD-alum) given twice subcutaneously to LADA patients at intervals of 4 weeks was safe and did not compromise beta-cell function in a Phase II clinical trial. GADA affinity has been shown to predict progression to type 1 diabetes. Here, we asked whether GADA affinity was affected by the GAD65 antigen-specific vaccination and/or associated with beta-cell function in participants of this trial. RESEARCH DESIGN AND METHODS GADA affinity was measured in sera of 46 LADA patients obtained prior to the first week and 20 weeks after the second injection with GAD-alum or placebo using competitive binding experiments with [I-125]-labeled and unlabeled human GAD65. RESULTS At baseline, GADA affinities ranged from 1.9 X 10(7) to 5.0 X 10(12) L/mol (median 2.8 X 10(19) L/mol) and were correlated with GADA titers (r = 0.47; P = 0.0009), fasting (r = 0.37; P = 0.01) and stimulated (r = -0.40; P = 0.006) C-peptide concentrations, and HbA(1c) (r = 0.39; P = 0.007). No significant changes in affinity were observed from baseline to week 24. Patients with GADA affinities in the lower first quartile (<4 X 10(9) L/mol) had better preserved fasting C-peptide concentrations at baseline than those with higher affinities (mean 1.02 vs. 0.66 nmol/L; P = 0.004) and retained higher concentrations over 30 months of follow-up (mean 1.26 vs. 0.62 nmol/L; P = 0.01). CONCLUSIONS Intervention with GAD-alum in LADA patients had no effect on GADA affinity. Our data suggest that patients with low GADA affinity have a prolonged preservation of residual beta-cell function.
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15. |
- Krischer, Jeffrey P., et al.
(author)
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Genetic and environmental interactions modify the risk of diabetes-related autoimmunity by 6 years of age : The teddy study
- 2017
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In: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 40:9, s. 1194-1202
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Journal article (peer-reviewed)abstract
- OBJECTIVE We tested the associations between genetic background and selected environmental exposures with respect to islet autoantibodies and type 1 diabetes. RESEARCH DESIGN AND METHODS Infants with HLA-DR high-risk genotypes were prospectively followed for diabetesrelated autoantibodies. Single nucleotide polymorphisms (SNPs) came from the Illumina ImmunoChip and environmental exposure data were by parental report. Children were followed to age 6 years. RESULTS Insulin autoantibodies occurred earlier than GAD antibody (GADA) and then declined, while GADA incidence rose and remained constant (significant in HLA-DR4 but not in the DR3/3 children). The presence of SNPs rs2476601 (PTPN22) and rs2292239 (ERBB3) demonstrated increased risk of both autoantibodies to insulin (IAA) only and GADA only. SNP rs689 (INS) was protective of IAA only, but not of GADA only. The rs3757247 (BACH2) SNP demonstrated increased risk of GADA only. Male sex, father or sibling as the diabetic proband, introduction of probiotics under 28 days of age, and weight at age 12 monthswere associated with IAA only, but only father as the diabetic proband and weight at age 12 months were associated with GADA only. Mother as the diabetic proband was not a significant risk factor. CONCLUSIONS These results show clear differences in the initiation of autoimmunity according to genetic factors and environmental exposures that give rise to IAAorGADA as the first appearing indication of autoimmunity.
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16. |
- Krischer, Jeffrey P., et al.
(author)
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The 6 year incidence of diabetes-associated autoantibodies in genetically at-risk children: the TEDDY study
- 2015
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In: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 58:5, s. 980-987
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Journal article (peer-reviewed)abstract
- Aims/hypothesis Islet autoantibodies, in addition to elevated blood glucose, define type 1 diabetes. These autoantibodies are detectable for a variable period of time before diabetes onset. Thus, the occurrence of islet autoantibodies is associated with the beginning of the disease process. The age at, and order in, which autoantibodies appear may be associated with different genetic backgrounds or environmental exposures, or both. Methods Infants with HLA-DR high-risk genotypes (DR3/4, DR4/4, DR4/8 and DR3/3) were enrolled and prospectively followed with standardised autoantibody assessments quarterly throughout the first 4 years of life and then semi-annually thereafter. Results Autoantibodies appeared in 549/8,503 (6.5%) children during 34,091 person-years of follow-up. Autoantibodies at 3 (0.1%) and 6 (0.2%) months of age were rare. Of the 549, 43.7% had islet autoantibodies to insulin (IAA) only, 37.7% had glutamic acid decarboxylase autoantibodies (GADA) only, 13.8% had both GADA and IAA only, 1.6% had insulinoma antigen-2 only and 3.1% had other combinations. The incidence of IAA only peaked within the first year of life and declined over the following 5 years, but GADA only increased until the second year and remained relatively constant. GADA only were more common than IAA only in HLA-DR3/3 children but less common in HLA-DR4/8 children. Conclusions/interpretation Islet autoantibodies can occur very early in life and the order of appearance was related to HLA-DR-DQ genotype.
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17. |
- Lind, Alexander, et al.
(author)
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First trimester enterovirus IgM and beta cell autoantibodies in mothers to children affected by type 1 diabetes autoimmunity before 7 years of age
- 2018
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In: Journal of Reproductive Immunology. - : Elsevier BV. - 0165-0378. ; 127, s. 1-6
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Journal article (peer-reviewed)abstract
- Background: Autoimmune (type 1) diabetes (T1D) is a frequent chronic disease in children and adolescents globally. Gestational enterovirus (EV) infections have been associated with an increased risk for T1D in the offspring. We test the hypothesis that EV infections during the first trimester were associated with beta cell autoantibodies in mothers of children who developed islet autoantibodies before 7 years of age. Materials and methods: Local registries were used to identify mothers to children born 2000–2007 who developed either beta cell autoantibodies or T1D during follow up. Serum samples from the first trimester were located in the Biobank. A total of 448 index mothers were identified and compared to 891 matched control mothers. EV-IgM was determined in a capture enzyme immunoassay. Beta cell autoantibodies were analyzed in standard radio binding assays. Results: The frequency of EV-IgM in index mothers was 20% (89/448), which did not differ from the control mothers 20% (175/891) (p = 0.922). Index mothers had multiple beta cell autoantibodies more often than control mothers (p = 0.037). Beta cell autoantibodies were increased during the November–April winter months in index compared to control mothers (p = 0.022). The observed difference was possibly explained by the months of February-April (p = 0.014). Concomitant EV-IgM and beta cell autoantibodies tended to be more common among index compared to control mothers (p = 0.039). Conclusion: EV-IgM during the first trimester may be associated with beta cell autoantibodies in mothers to children who developed either beta cell autoantibodies or T1D before 7 years of age.
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18. |
- Lindehammer, Sabina, et al.
(author)
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Temporal trends of HLA genotype frequencies of type 1 diabetes patients in Sweden from 1986 to 2005 suggest altered risk
- 2008
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In: Acta Diabetologica. - : Springer Science and Business Media LLC. - 0940-5429 .- 1432-5233. ; 45:4, s. 231-5
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Journal article (peer-reviewed)abstract
- The aim of this study was to compare the frequency of human leukocyte antigen (HLA) genotypes in 1-18-year-old patients with type 1 diabetes newly diagnosed in 1986-1987 (n = 430), 1996-2000 (n = 342) and in 2003-2005 (n = 171). We tested the hypothesis that the HLA DQ genotype distribution changes over time. Swedish type 1 diabetes patients and controls were typed for HLA using polymerase chain reaction amplification and allele specific probes for DQ A1* and B1* alleles. The most common type 1 diabetes HLA DQA1*-B1*genotype 0501-0201/0301-0302 was 36% (153/430) in 1986-1987 and 37% (127/342) in 1996-2000, but decreased to 19% (33/171) in 2003-2005 (P \ 0.0001). The 0501-0201/0501-0201 genotype increased from 1% in 1986-1987 to 7% in 1996-2000 (P = 0.0047) and to 5% in 2003-2005 (P > 0.05). This study in 1-18-year-old Swedish type 1 diabetes patients supports the notion that there is a temporal change in HLA risk.
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19. |
- Liu, Xiang, et al.
(author)
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Physical Activity and the Development of Islet Autoimmunity and Type 1 Diabetes in 5-15-Year-Old Children Followed in the TEDDY Study
- 2023
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In: Diabetes Care. - 1935-5548. ; 46:7, s. 1409-1416
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Journal article (peer-reviewed)abstract
- OBJECTIVE: This study investigated physical activity and its association with the development of islet autoimmunity and type 1 diabetes in genetically at-risk children aged 5-15 years.RESEARCH DESIGN AND METHODS: As part of the longitudinal Environmental Determinants of Diabetes in the Young (TEDDY) study, annual assessment of activity using accelerometry was conducted from age 5 years. Time-to-event analyses using Cox proportional hazard models were used to assess the association between time spent in moderate to vigorous physical activity per day and the appearance of one or several autoantibodies and progression to type 1 diabetes in three risk groups: 1) 3,869 islet autoantibody (IA)-negative children, of whom 157 became single IA positive; 2) 302 single IA-positive children, of whom 73 became multiple-IA positive; and 3) 294 multiple IA-positive children, of whom 148 developed type 1 diabetes.RESULTS: No significant association was found in risk group 1 or risk group 2. A significant association was seen in risk group 3 (hazard ratio 0.920 [95% CI 0.856, 0.988] per 10-min increase; P = 0.021), particularly when glutamate decarboxylase autoantibody was the first autoantibody (hazard ratio 0.883 [95% CI 0.783, 0.996] per 10-min increase; P = 0.043).CONCLUSIONS: More daily minutes spent in moderate to vigorous physical activity was associated with a reduced risk of progression to type 1 diabetes in children aged 5-15 years who had developed multiple IAs.
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20. |
- Lynch, Kristian F., et al.
(author)
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Gestational respiratory infections interacting with offspring HLA and CTLA-4 modifies incident β-cell autoantibodies
- 2018
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In: Journal of Autoimmunity. - : Elsevier BV. - 0896-8411. ; 86, s. 93-103
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Journal article (peer-reviewed)abstract
- β-cell autoantibodies against insulin (IAA), GAD65 (GADA) and IA-2 (IA-2A) precede onset of childhood type 1 diabetes (T1D). Incidence of the first appearing β-cell autoantibodies peaks at a young age and is patterned by T1D-associated genes, suggesting an early environmental influence. Here, we tested if gestational infections and interactions with child's human leukocyte antigen (HLA) and non-HLA genes affected the appearance of the first β-cell autoantibody. Singletons of mothers without diabetes (n = 7472) with T1D-associated HLA-DR-DQ genotypes were prospectively followed quarterly through the first 4 years of life, then semiannually until age 6 years, using standardized autoantibody analyses. Maternal infections during pregnancy were assessed via questionnaire 3-4.5 months post-delivery. Polymorphisms in twelve non-HLA genes associated with the first appearing β-cell autoantibodies were included in a Cox regression analysis. IAA predominated as the first appearing β-cell autoantibody in younger children (n = 226, median age at seroconversion 1.8 years) and GADA (n = 212; 3.2 years) in children aged ≥2 years. Gestational infections were not associated with the first appearing β-cell autoantibodies overall. However, gestational respiratory infections (G-RI) showed a consistent protective influence on IAA (HR 0.64, 95% CI 0.45-0.91) among CTLA4-(AG, GG) children (G-RI*. CTLA4 interaction, p = 0.002). The predominant associations of HLA-DR-DQ 4-8/8-4 with IAA and HLA-DR-DQ 3-2/3-2 with GADA were not observed if a G-RI was reported (G-RI*HLA-DR-DQ interaction, p = 0.03). The role of G-RI may depend on offspring HLA and CTLA-4 alleles and supports a bidirectional trigger for IAA or GADA as a first appearing β-cell autoantibody in early life.
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21. |
- Lönnrot, Maria, et al.
(author)
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Respiratory infections are temporally associated with initiation of type 1 diabetes autoimmunity : the TEDDY study
- 2017
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In: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 60:10, s. 1931-1940
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Journal article (peer-reviewed)abstract
- Aims/hypothesis: Respiratory infections and onset of islet autoimmunity are reported to correlate positively in two small prospective studies. The Environmental Determinants of Diabetes in the Young (TEDDY) study is the largest prospective international cohort study on the environmental determinants of type 1 diabetes that regularly monitors both clinical infections and islet autoantibodies. The aim was to confirm the influence of reported respiratory infections and to further characterise the temporal relationship with autoantibody seroconversion. Methods: During the years 2004–2009, 8676 newborn babies with HLA genotypes conferring an increased risk of type 1 diabetes were enrolled at 3 months of age to participate in a 15 year follow-up. In the present study, the association between parent-reported respiratory infections and islet autoantibodies at 3 month intervals up to 4 years of age was evaluated in 7869 children. Time-dependent proportional hazard models were used to assess how the timing of respiratory infections related to persistent confirmed islet autoimmunity, defined as autoantibody positivity against insulin, GAD and/or insulinoma antigen-2, concordant at two reference laboratories on two or more consecutive visits. Results: In total, 87,327 parent-reported respiratory infectious episodes were recorded while the children were under study surveillance for islet autoimmunity, and 454 children seroconverted. The number of respiratory infections occurring in a 9 month period was associated with the subsequent risk of autoimmunity (p < 0.001). For each 1/year rate increase in infections, the hazard of islet autoimmunity increased by 5.6% (95% CI 2.5%, 8.8%). The risk association was linked primarily to infections occurring in the winter (HR 1.42 [95% CI 1.16, 1.74]; p < 0.001). The types of respiratory infection independently associated with autoimmunity were common cold, influenza-like illness, sinusitis, and laryngitis/tracheitis, with HRs (95% CI) of 1.38 (1.11, 1.71), 2.37 (1.35, 4.15), 2.63 (1.22, 5.67) and 1.76 (1.04, 2.98), respectively. Conclusions/interpretation: Recent respiratory infections in young children correlate with an increased risk of islet autoimmunity in the TEDDY study. Further studies to identify the potential causative viruses with pathogen-specific assays should focus especially on the 9 month time window leading to autoantibody seroconversion.
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22. |
- Melin, Jessica, et al.
(author)
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Factors assessed in the first year of a longitudinal study predict subsequent study visit compliance : the TEDDY study
- 2023
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In: European Journal of Medical Research. - 0949-2321. ; 28:1
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Journal article (peer-reviewed)abstract
- Background: Compliance with a study protocol is central to meeting its research goals. In longitudinal research studies, data loss due to missed visits limit statistical power and introduce bias. The Environmental Determinants of Diabetes in the Young (TEDDY) study is a longitudinal multinational (US, Finland, Germany, and Sweden) investigation of children at risk for type 1 diabetes (T1D) that seeks to identify the environmental triggers of islet autoimmunity and T1D. The purpose of the current study was to identify sociodemographic variables and maternal characteristics assessed in the first year of TEDDY that were associated with study visit compliance in the subsequent 3 years. Methods: Sociodemographic variables, maternal life-style behaviors, post-partum depression, maternal reactions to the child’s T1D risk, and study-related variables were collected at child-age 6 months and 15 months. Multiple linear regression was used to examine the association of these variables to study visit compliance in the subsequent 3 years. Results: Study visit compliance was highest in Sweden (p > 0.001), in children who were their mother’s first child (p > 0.001), and whose mothers were older (p > 0.001) and more satisfied with the TEDDY study (p > 0.001). Father participation was also associated with better study visit compliance (p > 0.001). In contrast, children whose mothers smoked (p > 0.001), suffered from post-partum depression (p = 0.034), and were more anxious about their child’s T1D risk (p = 0.002), completed fewer visits. Father’s study satisfaction was also associated with study visit compliance (p = 0.029); however, it was not significant in models that included maternal study satisfaction. Conclusions: Sociodemographic variables, maternal characteristics—including study satisfaction—and fathers’ participation in the first year of a longitudinal study were associated with subsequent study visit compliance in a sample of children genetically at-risk for T1D followed for 4 years. This information can inform future strategies designed to improve study visit compliance in longitudinal pediatric studies. Trial registration: NCT00279318, 06/09/2004.
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23. |
- Melin, Jessica, et al.
(author)
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Is staff consistency important to parents' satisfaction in a longitudinal study of children at risk for type 1 diabetes : the TEDDY study
- 2022
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In: BMC Endocrine Disorders. - : Springer Science and Business Media LLC. - 1472-6823. ; 22
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Journal article (peer-reviewed)abstract
- BACKGROUND: Participants' study satisfaction is important for both compliance with study protocols and retention, but research on parent study satisfaction is rare. This study sought to identify factors associated with parent study satisfaction in The Environmental Determinants of Diabetes in the Young (TEDDY) study, a longitudinal, multinational (US, Finland, Germany, Sweden) study of children at risk for type 1 diabetes. The role of staff consistency to parent study satisfaction was a particular focus. METHODS: Parent study satisfaction was measured by questionnaire at child-age 15 months (5579 mothers, 4942 fathers) and child-age four years (4010 mothers, 3411 fathers). Multiple linear regression analyses were used to identify sociodemographic factors, parental characteristics, and study variables associated with parent study satisfaction at both time points. RESULTS: Parent study satisfaction was highest in Sweden and the US, compared to Finland. Parents who had an accurate perception of their child's type 1 diabetes risk and those who believed they can do something to prevent type 1 diabetes were more satisfied. More educated parents and those with higher depression scores had lower study satisfaction scores. After adjusting for these factors, greater study staff change frequency was associated with lower study satisfaction in European parents (mothers at child-age 15 months: - 0.30,95% Cl - 0.36, - 0.24, p < 0.001; mothers at child-age four years: -0.41, 95% Cl - 0.53, - 0.29, p < 0.001; fathers at child-age 15 months: -0.28, 95% Cl - 0.34, - 0.21, p < 0.001; fathers at child-age four years: -0.35, 95% Cl - 0.48, - 0.21, p < 0.001). Staff consistency was not associated with parent study satisfaction in the US. However, the number of staff changes was markedly higher in the US compared to Europe. CONCLUSIONS: Sociodemographic factors, parental characteristics, and study-related variables were all related to parent study satisfaction. Those that are potentially modifiable are of particular interest as possible targets of future efforts to improve parent study satisfaction. Three such factors were identified: parent accuracy about the child's type 1 diabetes risk, parent beliefs that something can be done to reduce the child's risk, and study staff consistency. However, staff consistency was important only for European parents. TRIAL REGISTRATION: NCT00279318 .
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24. |
- Mramba, Lazarus K., et al.
(author)
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Detecting potential outliers in longitudinal data with time-dependent covariates
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In: European Journal of Clinical Nutrition. - 0954-3007.
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Journal article (peer-reviewed)abstract
- Background: Outliers can influence regression model parameters and change the direction of the estimated effect, over-estimating or under-estimating the strength of the association between a response variable and an exposure of interest. Identifying visit-level outliers from longitudinal data with continuous time-dependent covariates is important when the distribution of such variable is highly skewed. Objectives: The primary objective was to identify potential outliers at follow-up visits using interquartile range (IQR) statistic and assess their influence on estimated Cox regression parameters. Methods: Study was motivated by a large TEDDY dietary longitudinal and time-to-event data with a continuous time-varying vitamin B12 intake as the exposure of interest and development of Islet Autoimmunity (IA) as the response variable. An IQR algorithm was applied to the TEDDY dataset to detect potential outliers at each visit. To assess the impact of detected outliers, data were analyzed using the extended time-dependent Cox model with robust sandwich estimator. Partial residual diagnostic plots were examined for highly influential outliers. Results: Extreme vitamin B12 observations that were cases of IA had a stronger influence on the Cox regression model than non-cases. Identified outliers changed the direction of hazard ratios, standard errors, or the strength of association with the risk of developing IA. Conclusion: At the exploratory data analysis stage, the IQR algorithm can be used as a data quality control tool to identify potential outliers at the visit level, which can be further investigated.
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25. |
- Smith, Laura B., et al.
(author)
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Factors Associated With Maternal-Reported Actions to Prevent Type 1 Diabetes in the First Year of the TEDDY Study
- 2014
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In: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 37:2, s. 325-331
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Journal article (peer-reviewed)abstract
- OBJECTIVEMothers of children at risk for type 1 diabetes report engaging in preventive behaviors. The purpose of this study is to further document these actions in an international, longitudinal sample and examine variables that predict whether mothers engage in these behaviors.RESEARCH DESIGN AND METHODSThis study examined an international sample (from Finland, Germany, Sweden, and the U.S.) from the naturalistic, longitudinal The Environmental Determinants of Diabetes in the Young (TEDDY) study, which tracked children genetically at risk for type 1 diabetes from birth to age 15 years. Mothers of 7,613 infants aged 6 months and 6,503 infants aged 15 months completed questionnaires assessing psychosocial factors and actions intended to prevent diabetes.RESULTSMany mothers (29.9% at 6 months and 42.8% at 15 months) reported engaging in a behavior intended to prevent type 1 diabetes, with the largest percentages (20.9-29.2%) reporting making changes to their child's diet (e.g., reducing the consumption of sweets and carbohydrates). Factors related to engaging in preventive behaviors include older maternal age; higher maternal education; minority status; having only one child; having a first-degree relative with type 1 diabetes; being from a country other than Sweden; having an accurate perception of the child's increased risk for developing diabetes; having postpartum depression, maternal anxiety, and worry about the risk of diabetes; and believing that diabetes can be prevented.CONCLUSIONSThe findings of this study suggest that many mothers engage in actions to prevent diabetes and highlight the importance of tracking these behaviors to ensure the validity of naturalistic observational studies.
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