To the Editor: I read the Putting Prevention Into Practice department by Drs. Tracer and Mohnot with great interest. They provided a case-based application of the U.S. Preventive Services Task Force recommendations for screening for prediabetes and type 2 diabetes mellitus in adults for a 36-year-old patient with a body mass index of 26 kg per m² and a history of gestational diabetes mellitus (GDM) three years before presentation.¹ The authors recommend screening based on the U.S. Preventive Services Task Force guidelines that all patients who have overweight or obesity should start screening at 35 years of age.¹

According to the American Diabetes Association guidelines, the patient would benefit from screening solely based on a history of GDM, regardless of age and body mass index.² GDM is associated with a 10-fold increased lifetime risk of developing type 2 diabetes compared with patients without GDM.² GDM can also represent previously undiagnosed prediabetes, type 2 diabetes, maturity-onset diabetes of the young, or even developing type 1 diabetes.² The American Diabetes Association recommends testing all women with GDM for persistent diabetes or prediabetes at four to 12 weeks postpartum with a 75-g oral glucose tolerance test.² If the postpartum oral glucose tolerance test result is normal, screening for type 2 diabetes should be performed every one to three years.²

In Reply: In our case-based piece, the patient meets the U.S. Preventive Services Task Force screening criteria by being older than 35 years and overweight. In accord with Dr. Sattari's letter, our piece notes that a history of gestational diabetes is a risk factor for prediabetes and type 2 diabetes. The U.S. Preventive Services Task Force recommendation on which our department is based also states that physicians should consider screening people at an earlier age if they have a history of gestational diabetes¹; however, that was not the focus of this specific scenario.