| 1. |
- Haghighi, Mona, et al.
(författare)
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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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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Jensen, Richard A., et al.
(författare)
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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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Ingår i: Journal of diabetes and its complications. - : Elsevier BV. - 1056-8727 .- 1873-460X. ; 21:4, s. 205-213
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Jensen, R., et al.
(författare)
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Islet cell autoantibody levels after the diagnosis of young adult diabetic patients
- 2007
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Ingår i: Diabetic Medicine. - : Wiley. - 0742-3071 .- 1464-5491. ; 24:11, s. 1221-1228
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Tidskriftsartikel (refereegranskat)abstract
- Aims The aim was to determine the course of islet cell antibodies [glutamate decarboxylase (GADA), tyrosine phosphatase-like islet antigen 2 (IA-2A) and islet cell (ICA)] after the diagnosis of the diabetic patient. Methods The Diabetes Incidence Study in Sweden (DISS) attempted to prospectively enrol all newly diagnosed diabetic patients aged 15–34 years during 1992 and 1993. C-peptide and autoantibody levels were determined from venous blood samples at diagnosis and again at yearly intervals for 6 years. Results After the first year, the odds of remaining GADA positive decreased by 9% per year [odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.85–0.96] while the mean GADA index remained unchanged ( = 0.8, P = 0.37). There was no change in the percentage of subjects testing IA-2A positive after the first year ( = 0.1, P = 0.75). However, the mean index decreased 0.04 per year (95% CI: 0.03–0.05)—a 7.9% decline (95% CI: 5.4–10.4%). The odds of a subject testing positive for ICA decreased by 24% per year (OR = 0.76, 95% CI = 0.70–0.82). The mean ICA levels decreased 0.75 per year (95% CI: 0.66–0.84)—a 16.4% decline (95% CI: 14.1–18.6%). The rate of change in titres for all three autoantibodies was independent of gender, human leucocyte antigen genotype and C-peptide status. Conclusions GADA levels remained high while ICA levels declined. In contrast to a previous study, we found that the proportion of IA-2A subjects remaining positive did not decrease after the first year, while the average index decreased slightly.
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| 4. |
- Larsson, Helena, et al.
(författare)
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Relationship between increased relative birthweight and infections during pregnancy in children with a high-risk diabetes HLA genotype.
- 2007
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 50:6, s. 1161-1169
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis Children with high-risk type 1 diabetes HLA genotype have increased risk of high relative birthweight (HrBW), while cord blood islet autoantibodies decrease the risk. As gestational infections may affect offspring type 1 diabetes risk, the aims were to test whether: (1) children of mothers reporting gestational infections have increased HrBW; (2) gestational infections explain islet autoantibody reduction of HrBW; and (3) gestational infections affect the association between HLA and HrBW. Subjects and methods HLA genotypes and autoantibodies to glutamic acid decarboxylase, insulinoma-associated protein 2 and insulin were determined in cord blood of children born to non-diabetic mothers in the Diabetes Prediction in Skane (DiPiS) study. Mothers reported gestational infections when the child was 2 months old. Results Fever or gastroenteritis during pregnancy was reported by 2,848/19,756 mothers (14%); 339 in more than one trimester. Children whose mothers reported infections had increased risk of HrBW (p=0.0003), particularly in the absence of cord blood islet autoantibodies (interaction between HrBW, islet autoantibodies and infections, p=0.0005). The effect on HrBW by high-risk HLA-DQ2/8 was aggravated by infections in more than one trimester (odds ratio [OR]=5.24; p=0.003) (interaction; p=0.022). When infections were reported, cord blood islet autoantibodies decreased HrBW (OR=0.34; p=0.0002). Conclusions/intrepretation This study revealed that: (1) gestational fever, gastroenteritis, or both, increased the risk of HrBW; (2) cord blood islet autoantibodies decreased the risk of HrBW only in combination with infections; and (3) infections aggravated the association between HLA-DQ2/8 and HrBW. These data suggest an interaction between HLA, gestational infections, islet autoantibodies and fetal growth.
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| 5. |
- Lernmark, Barbro, et al.
(författare)
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Cord blood islet autoantibodies are related to stress in the mother during pregnancy.
- 2006
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Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923. ; 1079:1079, s. 345-349
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Tidskriftsartikel (refereegranskat)abstract
- A 2-month psychological questionnaire concerning pregnancy was answered by 20,920 nondiabetic mothers of singletons. Retrospective analysis showed increased levels of islet autoantibodies (1A) in 290 (1.4%) newborns. High IA levels in the child's cord blood correlated strongly with IA levels in the mother (GADA r = 0.91, P < 0.0001; IA-2A r = 0.75, P = 0.0001). High IA levels were found in newborns whose mothers during pregnancy had been more worried than usual (P = 0.04), had worried that the child would be sick (P = 0.01) or not survive (P = 0.002), or had experienced serious life events, like "serious accident in the family" (P < 0.0001) or "experienced violence" (P = 0.02). Associations with increased worries by the mother remained in newborns with high type 1 diabetes mellitus (T1DM)-human leukocyte antigen (HLA) risk, but not in non-HLA risk children. ne prospective follow-up of these children will determine the importance of this early 1A for postnatal islet autoimmunity, type I diabetes, or both.
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| 6. |
- Lynch, Kristian, et al.
(författare)
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Cord blood islet autoantibodies and seasonal association with the type 1 diabetes high-risk genotype.
- 2008
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Ingår i: Journal of Perinatology. - : Springer Science and Business Media LLC. - 0743-8346 .- 1476-5543. ; 28:3, s. 211-217
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Tidskriftsartikel (refereegranskat)abstract
- Objective:Human leukocyte antigen DQ (HLA-DQ) genetic factors and islet autoantibodies are strongly associated with type 1 diabetes (T1D) and are currently used to predict T1D. This study examined whether islet autoantibodies in the cord blood of newborns to nondiabetic mothers were associated with the (T1D) high-risk genotype HLA-DQ2/8, gestational infections or both.Study Design:Cord blood samples were taken from 33 683 newborns and used for HLA typing and analyses of islet autoantibodies. Parents completed questionnaires when the child was 2 months of age.Result:The prevalence of newborn islet autoantibodies consistently varied with season over 4 years (P<0.0001); lowest in first quarter (1.2%) and highest in third (2.4%). Cord blood islet autoantibodies were associated with HLA-DQ2/8 in the second (OR, 2.30; P=0.02), third (OR, 2.12; P=0.008) and fourth quarters (OR, 2.49; P=0.007), but not in the first (OR, 1.13). Reported gastroenteritis was additionally associated with islet autoantibodies in the third quarter (OR, 1.80, P=0.04).Conclusion:An association between HLA and islet autoimmunity may depend on environmental exposure during pregnancy. Follow-up of mothers and children will determine risk of T1D.Journal of Perinatology (2008) 28, 211-217; doi:10.1038/sj.jp.7211912; published online 14 February 2008.
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| 7. |
- Papadopoulou, Anastasia, et al.
(författare)
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The type 1 diabetes protective HLA DQB1*0602 allele is less frequent in gestational diabetes mellitus.
- 2009
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 52, s. 1339-1342
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Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: We tested whether gestational diabetes mellitus (GDM) is associated with HLA-DQ genotypes. METHODS: A total of 764 mothers with non-autoimmune (GAD65, insulinoma-associated protein 2 [IA-2] and insulin autoantibody-negative) GDM were ascertained between September 2000 and August 2004 in the population-based Diabetes Prediction in Skåne (DiPiS) study. HLA-DQB1 genotypes were determined in these mothers and in 1191 randomly selected non-diabetic control mothers also negative for islet autoantibodies. The data were analysed in relation to maternal age, country of birth, number of pregnancies/siblings and pregnancy weight gain. RESULTS: The frequency of type 1 diabetes high-risk HLA-DQ alleles (DQB1*0201, DQB1*0302) did not differ between GDM mothers and controls. In contrast, the low-risk DQB1*0602 allele was less prevalent (OR 0.64, 95% CI = 0.51-0.80, p = 0.0006) in GDM than in control mothers. The difference in DQB1*0602 frequency between GDM mothers and controls remained after multiple logistic regression analysis correcting for maternal age, country of birth, number of pregnancies/siblings and weight gain during pregnancy (OR 0.67, 95% CI 0.51-0.88, p = 0.009). CONCLUSIONS/INTERPRETATION: The negative association between mothers who have non-autoimmune GDM and HLA-DQ*0602 suggest that this allele may protect not only from type 1 diabetes but also from GDM.
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| 8. |
- Agardh, Carl-David, et al.
(författare)
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Clinical evidence for the safety of GAD65 immunomodulation in adult-onset autoimmune diabetes.
- 2005
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Ingår i: Journal of Diabetes and its Complications. - : Elsevier BV. - 1873-460X .- 1056-8727. ; 19:4, s. 238-246
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this Phase II study was to evaluate if alum-formulated human recombinant GAD65 is safe and does not compromise beta cell function. The study was conducted as a randomized, double blind, placebo-controlled, dose-escalation clinical trial in a total of 47 Latent Autoimmune Diabetes in Adults (LADA) patients who received either placebo or 4, 20, 100, or 500 μg Diamyd subcutaneously at Weeks 1 and 4. Safety evaluations, including neurology, beta cell function tests, diabetes status assessment, hematology, biochemistry, and cellular and humoral immunological markers, were repeatedly assessed over 24 weeks. None of the patients had significant study-related adverse events (AE). Fasting c-peptide levels at 24 weeks were increased compared with placebo (P=.0015) in the 20 μg but not in the other dose groups. In addition, both fasting (P=.0081) and stimulated (P=.0236) c-peptide levels increased from baseline to 24 weeks in the 20 μg dose group. GADA log levels clearly increased (P=.0002) in response to 500 μg Diamyd. The CD4+CD25+/CD4+CD25− cell ratio increased (P=.0128) at 24 weeks in the 20 μg group. No sudden increase in HbA1c or plasma glucose or decrease in beta cell function was observed in any of the dose groups. These positive findings for clinical safety further support the clinical development of Diamyd as a therapeutic to prevent autoimmune diabetes.
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| 9. |
- Agardh, Carl-David, et al.
(författare)
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GAD65 vaccination: 5 years of follow-up in a randomised dose-escalating study in adult-onset autoimmune diabetes.
- 2009
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 52, s. 1363-1368
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Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: The aim of this study was to ascertain whether treatment of GAD65 autoantibody (GADA)-positive diabetic patients with alum-formulated recombinant GAD65 (GAD-alum) is safe and does not compromise beta cell function. METHODS: This Phase 2, placebo-controlled, dose-escalation clinical trial, which was randomized through a central office, was performed in 47 GADA-positive type 2 diabetic patients, who received subcutaneous injections of GAD-alum (4 [n = 9], 20 [n = 8], 100 [n = 9] or 500 [n = 8] mug) or placebo (n = 13) at weeks 1 and 4 of the trial. Participants and caregivers were blinded to group assignments. The primary outcome was safety as assessed by neurological tests, medications and beta cell function evaluated over 5 years, representing the end of the trial. RESULTS: No severe study-related adverse events occurred during the 5 year follow-up. None of the dose groups was associated with an increased risk of starting insulin treatment compared with the placebo group. The use of oral hypoglycaemic agents did not differ between the dose groups. After 5 years, fasting C-peptide levels declined in the placebo group (-0.24; 95% CI -0.41 to -0.07 log(10) nmol/l; p = 0.01) and the 500 microg dose group (-0.37; 95% CI -0.57 to -0.17 log(10) nmol/l; p = 0.003), but not in the 4 microg (-0.10; 95% CI -0.28 to 0.07 log(10) nmol/l; p = 0.20), 20 microg (0.04; 95% CI -0.12 to 0.19 log(10) nmol/l; p = 0.58) and 100 microg (0.00; 95% CI -0.20 to -0.20 log(10) nmol/l; p = 0.98) dose groups. CONCLUSIONS/INTERPRETATION: The primary outcome of safety was achieved, since no severe study-related adverse events occurred. TRIAL REGISTRATION: Because the study was initiated before 1 July 2005, the protocol was not registered in a registry. FUNDING: This trial was funded by the National Institutes of Health (grant numbers DK26190 and DK53004), the Swedish Research Council (grant number 72X-14064) and Diamyd Therapeutics (Stockholm, Sweden).
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