This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/dmrr.2900 This article is protected by copyright. All rights reserved. Title: Characteristics of the pre-diabetic period in children with high risk of type 1 diabetes recruited from the general Swedish population – the ABIS study Short title: Characteristics of pre-T1D in children Linda Åkerman 1 , Johnny Ludvigsson 1, 2 , Ulrica Swartling 3 , Rosaura Casas 1 1 Division of Pediatrics, Department of Clinical and Experimental Medicine, Linköping University, SE- 58185 Linköping, Sweden. 2 Pediatric Clinic, County Council of Östergötland, SE -58185 Linköping, Sweden. 3 Division of Diabetes and Celiac disease, Department of Clinical Sciences, Lund University, SE-20502 Malmö, Sweden Corresponding author: Linda Åkerman, Division of Pediatrics, Department of Clinical and Experimental Medicine, Linköping University, SE- 58185 Linköping, Sweden. e-mail: linda.akerman@liu.se , telephone: +46 (0)10-103 4662 Abstract Background There is a need for increased understanding of the pre-diabetic period in individuals with high risk of type 1 diabetes (T1D) from the general population. Methods High-risk children (n=21) positive for multiple islet autoantibodies were identified by autoantibody screening within the ABIS (All Babies in Southeast Sweden) study. The children and their parents were enrolled in a 2-year prospective follow-up study aiming to characterize the pre-diabetic period. Blood samples were collected every 6 months for measurement of C-peptide, HbA1c, fasting glucose and autoantibodies. HLA-genotype was determined, and oral glucose tolerance test was performed every 12 months. Results Despite positivity for multiple autoantibodies, 9 out of 21 individuals had low-risk HLA-genotypes. Children who progressed to manifest diabetes (progressors, n=12) had higher levels of IA2A and ZnT8A than children who did not (non-progressors, n=9). Impaired glucose tolerance and impaired fasting glucose was observed to the same extent in progressors and non-progressors, but HbA1c increased over time in progressors in spite of increased C-peptide. Conclusions