Update and Next Steps for Real-World Translation of Interventions for Type 2 Diabetes Prevention: Reflections From a Diabetes Care Editors' Expert Forum

Abstract

The International Diabetes Federation estimates that 415 million adults worldwide now have diabetes and 318 million have impaired glucose tolerance. These numbers are expected to increase to 642 million and 482 million, respectively, by 2040. This burgeoning pandemic places an enormous burden on countries worldwide, particularly resource-poor regions. Numerous landmark trials evaluating both intensive lifestyle modification and pharmacological interventions have persuasively demonstrated that type 2 diabetes can be prevented or its onset can be delayed in high-risk individuals with impaired glucose tolerance. However, key challenges remain, including how to scale up such approaches for widespread translation and implementation, how to select appropriately from various interventions and tailor them for different populations and settings, and how to ensure that preventive interventions yield clinically meaningful, cost-effective outcomes. In June 2015, a Diabetes Care Editors' Expert Forum convened to discuss these issues. This article, an outgrowth of the forum, begins with a summary of seminal prevention trials, followed by a discussion of considerations for selecting appropriate populations for intervention and the clinical implications of the various diagnostic criteria for prediabetes. The authors outline knowledge gaps in need of elucidation and explore a possible new avenue for securing regulatory approval of a prevention-related indication for metformin, as well as specific considerations for future pharmacological interventions to delay the onset of type 2 diabetes. They conclude with descriptions of some innovative, pragmatic translational initiatives already under way around the world.

Figure 1

Criteria for diagnosing diabetes and prediabetes. Diagnosis of diabetes is made on the basis of an FPG level ≥126 mg/dL (7.0 mmol/L), a 2-h plasma glucose level during an OGTT ≥200 mg/dL (11.1 mmol/L), or an A1C ≥6.5% (48 mmol/mol). When using A1C for diagnosis, it is important to take the patient’s age, race/ethnicity, and anemia/hemoglobinopathy status into consideration. Diabetes can also be diagnosed based on unequivocal symptoms and a random plasma glucose value ≥200 mg/dL (11.1 mmol/L). Any abnormality by any testing method must be repeated and confirmed on a separate day. For the diagnosis of prediabetes, cut points are not as well established. A 2-h plasma glucose during an OGTT of 140–199 mg/dL (7.8–11.0 mmol/L) is known as IGT and considered indicative of prediabetes, but recommended FPG and A1C cut points for prediabetes have varied (FPG ≥100–125 or ≥110–125 mg/dL [5.6–6.9 or 6.1–6.9 mmol/L] and A1C ≥5.7–6.4 or ≥6.0–6.4% [39–46 or 42–46 mmol/mol]). Adapted with permission from American Diabetes Association (45).