Single-Nucleotide Polymorphism rs7754840 of CDKAL1 Is Associated with Impaired Insulin Secretion in Nondiabetic Offspring of Type 2 Diabetic Subjects and in a Large Sample of Men with Normal Glucose Tolerance

Context: CDKAL1 is a recently discovered susceptibility gene for type 2 diabetes. Objective: Our objective was to investigate the impact of rs7754840 of CDKAL1 on insulin secretion, insulin sensitivity, and risk of type 2 diabetes. Design and Settings: Study 1 (the EUGENE2 study) was a cross-sectional study including subjects from five white populations in Europe (Denmark, Finland, Germany, Italy, and Sweden). Study 2 is an ongoing prospective study of Finnish men. Participants: In study 1, 846 nondiabetic offspring of type 2 diabetic patients (age 40 ± 10 yr; body mass index 26.7 ± 5.0 kg/m2) participated. In study 2, subjects included 3900 middle-aged men (533 type 2 diabetic and 3367 nondiabetic subjects). Interventions: Interventions included iv glucose-tolerance test (IVGTT), oral glucose-tolerance test (OGTT), and euglycemic-hyperinsulinemic clamp in study 1 and OGTT in study 2. Main Outcome Measures: Parameters of insulin secretion, insulin resistance, and glucose tolerance status were assessed. Re...