Kristine Færch, 1 Signe S. Torekov, 2,3 Dorte Vistisen, 1 Nanna B. Johansen, 1,4 Daniel R. Witte, 5 Anna Jonsson, 2 Oluf Pedersen, 2 Torben Hansen, 2 Torsten Lauritzen, 5 Annelli Sandbæk, 5 Jens Juul Holst, 2,3 and Marit E. Jørgensen 1 RESPONSE TO COMMENT ON FÆRCH ET AL. GLP-1 Response to Oral Glucose Is Reduced in Prediabetes, Screen-Detected Type 2 Diabetes, and Obesity and Influenced by Sex: The ADDITION-PRO Study. Diabetes 2015;64:2513–2525 Diabetes 2015;64:e30–e31 | DOI: 10.2337/db15-0743 We appreciate the comments from Theodorakis (1) in re- sponse to our findings of reduced glucagon-like peptide 1 (GLP-1) release in prediabetes, screen-detected type 2 diabe- tes, and obesity (2). Theodorakis suggests that participants with screen-detected diabetes in the ADDITION-PRO study may have had long-standing diabetes, which could then ex- plain why findings on GLP-1 release in participants with type 2 diabetes in the ADDITION-PRO study and the Bal- timore Longitudinal Study of Aging (BLSA) point in differ- ent directions. The ADDITION-PRO study performed in 2009–2011 was originally designed to quantify diabetes progression rates, examine early markers of micro- and macrovascular diabetes complications, and understand the related mechanisms in a large group of individuals at low to high risk of developing type 2 diabetes (3). The cohort for the ADDITION-PRO study was nested within the ADDITION-DK study—a population- based stepwise screening program in Danish general prac- tice performed in 2001–2006 (4). All individuals invited for the ADDITION-PRO examination had low diabetes risk, nor- mal glucose tolerance, or prediabetes in 2001–2006. Partic- ipants diagnosed with diabetes since the examination in 2001–2006 or people reporting the use of antidiabetic medica- tion at the examination in 2009–2011 were excluded from the analysis (2). At the 2009–2011 examination, 163 individuals without known diabetes were diagnosed with screen- detected diabetes. Of these, 76 had normal glucose tolerance, 80 had prediabetes, and 7 scored low on a questionnaire for diabetes risk in 2001–2006. Therefore, it is unlikely that participants diagnosed with screen-detected diabetes at the examination in 2009–2011 had long-standing diabetes, and they were not receiving antidiabetic treatment prior to their study attendance. In fact, the 163 participants with screen-detected diabetes in the ADDITION-PRO study had on average a “healthier” phenotype than the 17 patients with type 2 diabetes who participated in the BLSA, in which increased release of GLP-1 was found (5). All 17 individuals with diabetes in the BLSA had both diabetic fasting and 2-h glucose values, and they had an average HbA 1c level of 7.0% (5). In the ADDITION-PRO study (2), 82 were diagnosed with diabetes by fasting glucose only, 43 by 2-h glucose only, and 38 by both fasting and 2-h glucose concentrations, and the average HbA 1c level was 6.1%. Di- agnosis of diabetes by only the fasting or the 2-h glucose criterion is associated with a less severe phenotype than diagnosis by both criteria (6), underscoring that individuals with screen-detected diabetes in the ADDITION-PRO study were diagnosed at an early stage of their disease. We agree with Theodorakis that differences in the duration and severity of type 2 diabetes are likely to 1 Steno Diabetes Center, Gentofte, Denmark 2 NNF Center for Basic Metabolic Research, University of Copenhagen, Copenha- gen, Denmark 3 Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark 4 Danish Diabetes Academy, Odense, Denmark 5 Section for General Practice, Department of Public Health, Aarhus, Denmark Corresponding author: Kristine Færch, krif@steno.dk. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. e30 Diabetes Volume 64, September 2015 e-LETTERS – COMMENTS AND RESPONSES