Oana P Zaharia, Klaus Strassburger, Alexander Strom, Gidon J Bönhof, Yanislava Karusheva, Sofia Antoniou, Kálmán Bódis, Daniel F Markgraf, Volker Burkart, Karsten Müssig, Jong-Hee Hwang, Olof Asplund, Leif Groop, Emma Ahlqvist, Jochen Seissler, Peter Nawroth, Stefan Kopf, Sebastian M Schmid, Michael Stumvoll, Andreas F H Pfeiffer, Stefan Kabisch, Sergey Tselmin, Hans U Häring, Dan Ziegler, Oliver Kuss, Julia Szendroedi, Michael Roden, Bengt-Frederik Belgardt, Anette Buyken, Jürgen Eckel, Gerd Geerling, Hadi Al-Hasani, Christian Herder, Andrea Icks, Jörg Kotzka, Eckart Lammert, Daniel Markgraf, and Wolfgang Rathmann
Summary Background Cluster analyses have proposed different diabetes phenotypes using age, BMI, glycaemia, homoeostasis model estimates, and islet autoantibodies. We tested whether comprehensive phenotyping validates and further characterises these clusters at diagnosis and whether relevant diabetes-related complications differ among these clusters, during 5-years of follow-up. Methods Patients with newly diagnosed type 1 or type 2 diabetes in the German Diabetes Study underwent comprehensive phenotyping and assessment of laboratory variables. Insulin sensitivity was assessed using hyperinsulinaemic-euglycaemic clamps, hepatocellular lipid content using magnetic resonance spectroscopy, hepatic fibrosis using non-invasive scores, and peripheral and autonomic neuropathy using functional and clinical criteria. Patients were reassessed after 5 years. The German Diabetes Study is registered with ClinicalTrials.gov , number NCT01055093 , and is ongoing. Findings 1105 patients were classified at baseline into five clusters, with 386 (35%) assigned to mild age-related diabetes (MARD), 323 (29%) to mild obesity-related diabetes (MOD), 247 (22%) to severe autoimmune diabetes (SAID), 121 (11%) to severe insulin-resistant diabetes (SIRD), and 28 (3%) to severe insulin-deficient diabetes (SIDD). At 5-year follow-up, 367 patients were reassessed, 128 (35%) with MARD, 106 (29%) with MOD, 88 (24%) with SAID, 35 (10%) with SIRD, and ten (3%) with SIDD. Whole-body insulin sensitivity was lowest in patients with SIRD at baseline (mean 4·3 mg/kg per min [SD 2·0]) compared with those with SAID (8·4 mg/kg per min [3·2]; p Interpretation Cluster analysis can characterise cohorts with different degrees of whole-body and adipose-tissue insulin resistance. Specific diabetes clusters show different prevalence of diabetes complications at early stages of non-alcoholic fatty liver disease and diabetic neuropathy. These findings could help improve targeted prevention and treatment and enable precision medicine for diabetes and its comorbidities. Funding German Diabetes Center, German Federal Ministry of Health, Ministry of Culture and Science of the state of North Rhine-Westphalia, German Federal Ministry of Education and Research, German Diabetes Association, German Center for Diabetes Research, Research Network SFB 1116 of the German Research Foundation, and Schmutzler Stiftung.