Steffen U. Thorsen
University of Copenhagen
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Steffen U. Thorsen.
Diabetes Care | 2013
Steffen U. Thorsen; Henrik B. Mortensen; Bendix Carstensen; Mogens Fenger; Betina H. Thuesen; Lise Lotte N. Husemoen; Regine Bergholdt; Caroline Brorsson; Flemming Pociot; Allan Linneberg; Jannet Svensson
The causes of the worldwide increase in type 1 diabetes (T1D) in children are still largely unknown. In Denmark, the increase in incidence is steep at 3.4% annually and does not appear to be leveling out (1). Lower levels of 25-hydroxyvitamin D [25(OH)D] have been found in patients with newly diagnosed T1D compared with healthy control subjects, implying that 25(OH)D might play a role in the pathogenesis of T1D (2,3). We aimed to elucidate the possible association between low levels of 25(OH)D and T1D by measuring 25(OH)D levels in children with newly diagnosed T1D and their healthy siblings in Denmark across a 13-year study period (1997–2009). We included 1,803 children (907 T1D patients and 896 siblings) in the data analyses. The children were aged 0–18 years (mean …
Pediatric Diabetes | 2014
Steffen U. Thorsen; Henrik B. Mortensen; Bendix Carstensen; Mogens Fenger; Betina H. Thuesen; L. L. N. Husemoen; Regine Bergholdt; Caroline Brorsson; Flemming Pociot; Allan Linneberg; Jannet Svensson
Vitamin D, certain single nucleotide polymorphisms (SNPs) in the vitamin D‐receptor (VDR) gene and vitamin D metabolism genes have been associated with type 1 diabetes (T1D).
Scandinavian Journal of Immunology | 2014
Steffen U. Thorsen; Stefanie Eising; Henrik B. Mortensen; Kristin Skogstrand; Flemming Pociot; Jesper Johannesen; Jannet Svensson
The mechanisms by which antigen‐specific T cells migrate to the islets of Langerhans in type 1 diabetes (T1D) are largely unknown. Chemokines attract immune cells to sites of inflammation. The aim was to elucidate the role of inflammatory chemokines in T1D at time of diagnosis. From a population‐based registry of children diagnosed with T1D from 1997 to 2005, we studied five different inflammatory chemokines (CCL2, CCL3, CCL4, CCL5 and CXCL8). Four hundred and eighty‐two cases and 479 sibling frequencies matched on age and sample year distribution were included. Patients showed lower levels of CCL4 compared to siblings, but this result was not significant after correction for multiple testing. CCL2, CCL3, CCL4 and CXCL8 levels were highest in the most recent cohorts (P < 0.01) in both patients and siblings. A significant seasonal variation – for most of the chemokines – was demonstrated with the highest level during the summer period in both patients and siblings. In addition, there was a significant inverse relationship between CCL4 levels and age. When comparing patients and siblings, remarkably few differences were identified, but interestingly chemokine levels varied with age, season and period for the entire study population. Such variations should be taken into account when studying chemokines in paediatric populations.
Clinical Immunology | 2017
Steffen U. Thorsen; Christian B. Pipper; Stefanie Eising; Kristin Skogstrand; David M. Hougaard; Jannet Svensson; Flemming Pociot
BACKGROUND/AIM An in-depth understanding of the early phase of type 1 diabetes (T1D) pathogenesis is important for targeting primary prevention. We examined if 14 preselected mediators of immune responses differed in neonates that later developed T1D compared to control neonates. METHODS The study is a case-control study with a 1:2 matching. The individuals were born between 1981 through 2002. Cases were validated using the National Patient Register and the Danish Childhood Diabetes Register. Interleukin(IL)-1β, IL-4, IL-6, IL-8, IL-10, IL-12p70, interferon gamma, tumor necrosis factor alpha, transforming growth factor beta 1 (active form), leptin, adiponectin, c-reactive protein, mannose-binding lectin and soluble triggering receptor expressed on myeloid cells-1 were measured by using a flowmetric Luminex xMAP® technology. We tested two models both including a number of possible confounders. In the first model (model 1) we also adjusted for HLA-DQB1 genotype. A total of 1930 groups of assay-matched cases and controls (4746 individuals) were included in the statistical analyses. RESULTS Adiponectin was negatively associated with later risk of T1D in both models (relative change (RC), model 1: 0.95, P=0.046 and model 2: 0.95, P=0.006). IL-10 and IL-12 were both positively associated with T1D risk in the model 2 (RC, 1.19, P=0.006 and 1.07, P=0.02, respectively)-these results were borderline significant in model 1, but showed the same direction as the results from model 2. CONCLUSIONS Our results indicate that specific immunological signatures are already present at time of birth in children developing T1D before the age of 18years.
American Journal of Epidemiology | 2018
Steffen U. Thorsen; Karl Mårild; Sjurdur F. Olsen; Klaus K. Holst; German Tapia; Charlotta Granström; Thorhallur I. Halldorsson; Arieh Cohen; Margaretha Haugen; Marika Lundqvist; Torild Skrivarhaug; Pål R. Njølstad; Geir Joner; Per Magnus; Ketil Størdal; Jannet Svensson; Lars C. Stene
Studies on vitamin D status during pregnancy and risk of type 1 diabetes mellitus (T1D) lack consistency and are limited by small sample sizes or single measures of 25-hydroxyvitamin D (25(OH)D). We investigated whether average maternal 25(OH)D plasma concentrations during pregnancy are associated with risk of childhood T1D. In a case-cohort design, we identified 459 children with T1D and a random sample (n = 1,561) from the Danish National Birth Cohort (n = 97,127) and Norwegian Mother and Child Cohort Study (n = 113,053). Participants were born between 1996 and 2009. The primary exposure was the estimated average 25(OH)D concentration, based on serial samples from the first trimester until delivery and on umbilical cord plasma. We estimated hazard ratios using weighted Cox regression adjusting for multiple confounders. The adjusted hazard ratio for T1D per 10-nmol/L increase in the estimated average 25(OH)D concentration was 1.00 (95% confidence interval: 0.90, 1.10). Results were consistent in both cohorts, in multiple sensitivity analyses, and when we analyzed mid-pregnancy or cord blood separately. In conclusion, our large study demonstrated that normal variation in maternal or neonatal 25(OH)D is unlikely to have a clinically important effect on risk of childhood T1D.
Pediatric Diabetes | 2017
Steffen U. Thorsen; Christian B. Pipper; Henrik B. Mortensen; Kristin Skogstrand; Flemming Pociot; Jesper Johannesen; Jannet Svensson
Type 1 diabetes (T1D) is an organ‐specific autoimmune disease with an increase in incidence worldwide including Denmark. The triggering receptor expressed on myeloid cells‐1 (TREM‐1) is a potent amplifier of pro‐inflammatory responses and has been linked to autoimmunity, severe psychiatric disorders, sepsis, and cancer.
Scandinavian Journal of Rheumatology | 2017
Steffen U. Thorsen; Christian B. Pipper; M Alberdi-Saugstrup; S Nielsen; A Cohen; M Lundqvist; Lau Caspar Thygesen; Alberto Ascherio; J Svensson
Objectives: Basic and epidemiological studies on rheumatic autoimmune diseases have suggested an association between vitamin D levels around time of birth and disease risk. The literature on vitamin D and juvenile idiopathic arthritis (JIA) is scarce. We hypothesized that low levels of 25-hydroxyvitamin D [25(OH)D] around time of birth would be associated with increased risk of oligo- or polyarticular JIA. Method: We conducted a case–cohort study of validated cases diagnosed with oligo- and polyarticular JIA (1993–2012) and controls matched on date of birth. Cases and controls were born in the period 1983–2010. Cases were diagnosed using international criteria. The concentration of 25(OH)D was assessed from neonatal dried blood spot (DBS) samples using high-sensitivity liquid chromatography tandem mass spectrometry (LC-MS/MS). Odds ratios (ORs) were calculated using conditional logistic regression and a two-way analysis of variance (ANOVA) was used to test for season and birth year 25(OH)D variations. A total of 300 matched pairs were included in the statistical analyses. Results: No significant association was found between levels of 25(OH)D and JIA risk in the adjusted model [OR (per 25 nmol/L increase) 1.2, 95% confidence interval (CI) 0.9–1.6, p = 0.2]. 25(OH)D levels were found to fluctuate significantly with season (p < 0.0001) and year (p < 0.0001). The median level of 25(OH)D was 34.4 nmol/L in cases and 31.5 nmol/L in controls. Conclusions: Our study does not support the hypothesis that a window of vulnerability exists around time of birth with regard to 25(OH)D levels and later JIA risk. Further studies should explore whether 25(OH)D levels during early pregnancy or infancy may influence JIA risk.
Nutrients | 2017
Julie N. Kyvsgaard; Anne Julie Overgaard; Steffen U. Thorsen; Thomas H. Hansen; Christian B. Pipper; Henrik B. Mortensen; Flemming Pociot; Jannet Svensson
(1) Background: Iron requirement increases during pregnancy and iron supplementation is therefore recommended in many countries. However, excessive iron intake may lead to destruction of pancreatic β-cells. Therefore, we aim to test if higher neonatal iron content in blood is associated with the risk of developing type 1 diabetes mellitus (T1D) in childhood; (2) Methods: A case-control study was conducted, including 199 children diagnosed with T1D before the age of 16 years from 1991 to 2005 and 199 controls matched on date of birth. Information on confounders was available in 181 cases and 154 controls. Iron was measured on a neonatal single dried blood spot sample and was analyzed by laser ablation inductively coupled plasma mass spectrometry. Multivariate logistic regression was used to evaluate if iron content in whole blood was associated with the risk of T1D; (3) Results: A doubling of iron content increased the odds of developing T1D more than two-fold (odds ratio (95% CI), 2.55 (1.04; 6.24)). Iron content increased with maternal age (p = 0.04) and girls had higher content than boys (p = 0.01); (4) Conclusions: Higher neonatal iron content associates to an increased risk of developing T1D before the age of 16 years. Iron supplementation during early childhood needs further investigation, including the causes of high iron in neonates.
Scandinavian Journal of Gastroenterology | 2016
Steffen U. Thorsen; Christian Jakobsen; Arieh Cohen; Marika Lundqvist; Lau Caspar Thygesen; Christian B. Pipper; Alberto Ascherio; Jannet Svensson
ABSTRACT Objective Basic and epidemiologic studies on inflammatory bowel disease (IBD) have suggested an association between vitamin D and IBD risk. Though, the literature on IBD – especially pediatric-onset IBD – and vitamin D is still in its cradle. We therefore wanted to examine if levels of 25(OH)D at birth were associated with increased risk of developing pediatric-onset IBD. Material and methods A case-cohort study composed of cases diagnosed with Crohn’s disease, ulcerative colitis or indeterminate/unclassified colitis and healthy controls. Cases and controls were matched on date of birth and were born in the period 1981–2004. Cases were diagnosed before the age of 18 years. The concentration of 25(OH)D was assessed from neonatal dried blood spots using a highly sensitive liquid chromatography tandem mass spectrometry. Odds ratios (OR) were calculated using conditional logistic regression and two-way ANOVA were used to test for season and birth year 25(OH)D variations. A total of 384 matched pairs were included in the statistical analyses. Results No significant association were found between levels of 25(OH)D and IBD risk in the adjusted model (OR [95% CI] (per 25 nmol/L increase), 1.12 [0.88; 1.42], p = 0.35). 25(OH)D levels were found to fluctuate significantly with season (p < 0.001) and year (p < 0.001). Median/Q1–Q3 values for 25(OH)D were 27.1/16.5–39.5 nmol/L for cases and 25.7/16.1–39.4 nmol/L for controls. Conclusion Our study do not suggest that a window of vulnerability exist around time of birth in regards to 25(OH)D levels and later pediatric-onset IBD risk.
International Journal of Endocrinology | 2016
Steffen U. Thorsen; Christian B. Pipper; Henrik B. Mortensen; Flemming Pociot; Jesper Johannesen; Jannet Svensson
Aims. A new perspective on autoantibodies as pivotal players in the pathogenesis of type 1 diabetes (T1D) has recently emerged. Our key objective was to examine whether increased levels of autoantibodies against the β-cell autoantigens glutamic acid decarboxylase (isoform 65) (GADA) and insulinoma associated antigen-2A (IA-2A) mirrored the 3.4% annual increase in incidence of T1D. Methods. From the Danish Childhood Diabetes Register, we randomly selected 500 patients and 500 siblings for GADA and IA-2A analysis (1997 through 2005). Blood samples were taken within three months after onset. A robust log-normal regression model was used. Nine hundred children and adolescents had complete records and were included in the analysis. Cochran-Armitage test for trend was used to evaluate changes in prevalence of autoantibody positivity by period. Results. No significant changes in levels of GADA and IA-2A were found over our 9-year study period. No trends in autoantibody positivity—in either patients or siblings—were found. Levels of GADA and IA-2A were significantly associated with HLA risk groups and GADA with age. Conclusion. The prevalence of positivity and the levels of GADA and IA-2A have not changed between 1997 and 2005 in newly diagnosed patients with T1D and their siblings without T1D.