Prediabetes diagnosis criteria, type 2 diabetes risk and dietary modulation: The CORDIOPREV study

Aim: Our objective was to investigate the role of two healthy diets in modulating the risk of type 2 diabetes (T2DM) development associated with each prediabetes diagnosis criteria in coronary heart disease patients. Additionally, we explored the pathophysiological characteristics and the risk of developing T2DM in patients with different prediabetes criteria. Methods: We included 462 patients from the CORDIOPREV study without T2DM at baseline: 213 had prediabetes defined by impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) (PreDM-IFG/IGT): 180 had prediabetes by isolated hemoglobin glycated plasma levels (PreDM-isolated-HbA1c), and 69 were not prediabetics (non-PreDM), according to the American Diabetes Association criteria. Patients were randomized to consume either a Mediterranean or a low-fat diet. We performed a COX proportional hazards regression analysis to determine the T2DM risk according to diet and the prediabetes criteria after a median follow-up of 60 months. Results: We found higher T2DM risk (HR: 2.98; 95% CI 1.27-6.98) in PreDM-IFG/IGT than in PreDM-isolated-HbA1c (HR: 2.31; 95% Cl 0.97-5.49) compared with non-PreDM. Long-term consumption of a low-fat diet was associated with a lower risk of T2DM when compared to the Mediterranean diet in the PreDM-IFG/IGT group (HR: 3.20; 95% Cl 0.75-13.69 versus HR: 4.70; 95% CI 1.12-19.67, respectively). Moreover, we found the highest risk of T2DM development associated with patients who had both IFG and IGT (HR: 2.15; 95% CI 1.11-4.16). Patients who had both IFG and IGT and consumed a low-fat diet had a lower T2DM risk than those who consumed a Mediterranean diet (HR: 1.53; 95% CI 0.53-4.39 versus HR: 3.33; 95% CI 1.34-8.30, respectively). Conclusion: Our results suggest that the type of diet consumed may modulate the risk of T2DM development according to the prediabetes diagnosis criteria. Specifically, our study showed that the consumption of a low-fat diet was more beneficial than a Mediterranean diet in patients with IFG and IGT. (C) 2019 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.