Azra Kurbasic, Femke Rutters, Markku Laakso, Joline W.J. Beulens, Caroline Brorsson, Mark Walker, Tarja Kokkola, Emmanouil T. Dermitzakis, Gary Frost, Andrew T. Hattersley, Hartmut Ruetten, Søren Brunak, Simone P. Rauh, Federico De Masi, Ramneek Gupta, Imre Pavo, Christopher J. Groves, Jerzy Adamski, Andrea Tura, Bernd Jablonka, Alison Heggie, Tue H. Hansen, Ana Viñuela, Martin Ridderstråle, Andrea Mari, Jane Kaye, Henrik Vestergaard, Robert W. Koivula, Kristine H. Allin, Harriet Teare, Michelle Hudson, Thomas E. White, Jochen M. Schwenk, Mark I. McCarthy, Maritta Siloaho, Mandy H Perry, Ewan R. Pearson, Oluf Pedersen, Ian M Forgie, Timothy J. McDonald, Soren Brage, Anubha Mahajan, E. Louise Thomas, Paul W. Franks, Anitra D.M. Koopman, Philippe Froguel, Torben Hansen, Jimmy D. Bell, Giuseppe N. Giordano, Adem Y. Dawed, Koivula, Robert W. [0000-0002-1646-4163], Pearson, Ewan [0000-0001-9237-8585], Franks, Paul W. [0000-0002-0520-7604], Apollo - University of Cambridge Repository, Vinuela Rodriguez, Ana, Dermitzakis, Emmanouil, Epidemiology and Data Science, APH - Health Behaviors & Chronic Diseases, APH - Methodology, ACS - Diabetes & metabolism, APH - Aging & Later Life, ACS - Heart failure & arrhythmias, Koivula, Robert W [0000-0002-1646-4163], and Franks, Paul W [0000-0002-0520-7604]
Aims/hypothesis Here, we describe the characteristics of the Innovative Medicines Initiative (IMI) Diabetes Research on Patient Stratification (DIRECT) epidemiological cohorts at baseline and follow-up examinations (18, 36 and 48 months of follow-up). Methods From a sampling frame of 24,682 adults of European ancestry enrolled in population-based cohorts across Europe, participants at varying risk of glycaemic deterioration were identified using a risk prediction algorithm (based on age, BMI, waist circumference, use of antihypertensive medication, smoking status and parental history of type 2 diabetes) and enrolled into a prospective cohort study (n = 2127) (cohort 1, prediabetes risk). We also recruited people from clinical registries with type 2 diabetes diagnosed 6–24 months previously (n = 789) into a second cohort study (cohort 2, diabetes). Follow-up examinations took place at ~18 months (both cohorts) and at ~48 months (cohort 1) or ~36 months (cohort 2) after baseline examinations. The cohorts were studied in parallel using matched protocols across seven clinical centres in northern Europe. Results Using ADA 2011 glycaemic categories, 33% (n = 693) of cohort 1 (prediabetes risk) had normal glucose regulation and 67% (n = 1419) had impaired glucose regulation. Seventy-six per cent of participants in cohort 1 was male. Cohort 1 participants had the following characteristics (mean ± SD) at baseline: age 62 (6.2) years; BMI 27.9 (4.0) kg/m2; fasting glucose 5.7 (0.6) mmol/l; 2 h glucose 5.9 (1.6) mmol/l. At the final follow-up examination the participants’ clinical characteristics were as follows: fasting glucose 6.0 (0.6) mmol/l; 2 h OGTT glucose 6.5 (2.0) mmol/l. In cohort 2 (diabetes), 66% (n = 517) were treated by lifestyle modification and 34% (n = 272) were treated with metformin plus lifestyle modification at enrolment. Fifty-eight per cent of participants in cohort 2 was male. Cohort 2 participants had the following characteristics at baseline: age 62 (8.1) years; BMI 30.5 (5.0) kg/m2; fasting glucose 7.2 (1.4) mmol/l; 2 h glucose 8.6 (2.8) mmol/l. At the final follow-up examination, the participants’ clinical characteristics were as follows: fasting glucose 7.9 (2.0) mmol/l; 2 h mixed-meal tolerance test glucose 9.9 (3.4) mmol/l. Conclusions/interpretation The IMI DIRECT cohorts are intensely characterised, with a wide-variety of metabolically relevant measures assessed prospectively. We anticipate that the cohorts, made available through managed access, will provide a powerful resource for biomarker discovery, multivariate aetiological analyses and reclassification of patients for the prevention and treatment of type 2 diabetes. Electronic supplementary material The online version of this article (10.1007/s00125-019-4906-1) contains peer-reviewed but unedited supplementary material, which is available to authorised users.