Screening for diabetes and prediabetes should now begin at age 35 years in patients who are overweight or obese, the U.S. Preventive Services Task Force (USPSTF) recently recommended.
Based on a systematic review, the USPSTF updated its 2015 recommendation on the subject, lowering the age at which to begin screening from 40 years to 35 years. It now recommends screening nonpregnant adults ages 35 to 70 years who have overweight or obesity (defined as a body mass index ≥ 25 kg/m2) and no symptoms of diabetes (grade B recommendation). Clinicians should then offer or refer patients with prediabetes to effective preventive interventions. This is based on the Task Force having concluded with moderate certainty that screening for prediabetes and type 2 diabetes and offering or referring interventions to patients with prediabetes have a moderate net benefit.
Another change to the 2015 recommendation is the inclusion of metformin on the list of interventions that have demonstrated efficacy in preventing or delaying progression to diabetes, along with diet and exercise. The USPSTF noted that metformin has not been FDA approved for this indication. The recommendation and the systematic review on which it was based were published in the Aug. 24/31 JAMA.
The review included 89 publications with 68,882 patients. The two randomized trials of screening for diabetes that were included found no significant mortality benefit but had insufficient data to assess other health outcomes and didn't identify harms. Other studies showed that for patients with recently diagnosed (not screen-detected) diabetes, interventions improved health outcomes. For patients with prediabetes, interventions were associated with reduced incidence of diabetes and improvement in other outcomes, the review found.
An accompanying editorial noted that the review's findings on screening seem to contradict the USPSTF's recommendation. “Thus, the rationale to screen depends on the benefits of the interventions that follow diagnosis, including the long-term attention to risk factor management and the opportunity to prevent diabetes in the large population at risk,” the editorial said. The editorialists called for “development of a broader framework for diabetes prevention that matches risk tiers to diverse evidence-based interventions to serve individuals at varying levels of risk and that provides more personalized prevention or metformin,” noting that the new guidance may be most valuable if it “can reach young and vulnerable adults.”