In December 2015, the US Preventive Services Task Force (USPSTF) published an update to their 2008 recommendations for diabetes screening in asymptomatic adults.1 The USPSTF recommends that all adults aged 40 to 70 years be screened for abnormal blood glucose, and that asymptomatic adults with hypertension (ie, sustained blood pressure of >135/80 mm Hg) be screened for diabetes. However, people with a family history of diabetes, gestational diabetes, or polycystic ovarian syndrome, or who are of certain races/ethnicities (eg, African Americans, Asian Americans, American Indians, or Alaskan Natives) may have an increased risk for diabetes despite being younger or having a lower body mass index than patients who are typically diagnosed with diabetes.
Citing estimates from 2012, the USPSTF reports that approximately 86 million Americans aged ≥20 years have impaired fasting glucose or impaired glucose tolerance, and approximately 15% to 30% of this population will have diabetes ≤5 years if they fail to make health-improving lifestyle changes. Such lifestyle changes include methods for modifying being overweight or obese, lowering the percentage of abdominal fat, increasing physical activity, and stopping smoking. In its last recommendation statement, the USPSTF reported that although there was evidence of an association between measuring blood glucose and short-term anxiety, the harms of lifestyle interventions to reduce the incidence of diabetes are few to none.1 In addition, 6 new studies of lifestyle interventions have shown that lifestyle modifications can prevent or delay progression to diabetes, improving clinical outcomes as a result. This new data has led the USPSTF to the conclusion that there is a moderate net benefit to measuring blood glucose in adults who are at increased risk for diabetes.
Although intensive behavioral interventions combining dietary counseling and physical activity have an effect on delaying or avoiding the progression of glucose abnormalities to type 2 diabetes, the USPSTF previously found that there was insufficient evidence that pharmacologic interventions provide the same benefits (eg, weight loss or reducing glucose levels, blood pressure, and lipid levels). A review of 8 studies published since the previous recommendations, however, revealed that metformin, thiazolidinediones, and α-glucosidase inhibitors were effective in preventing or delaying diabetes progression.1
Despite being unable to find any trials that evaluated the benefits of initiating interventions at the time of diabetes screening versus after clinical diagnosis, the USPSTF identified 3 trials where intensive lifestyle modification interventions in patients with impaired fasting glucose or impaired glucose tolerance was associated with better quality of life at follow-up 3 years later.
“Clinical trials and additional modeling studies are needed to better elucidate the optimal frequency of screening and the age at which to start screening,” the researchers concluded. “More US data are also needed on the benefits and harms of lifestyle interventions and medical treatments for screen-detected [impaired fasting glucose], [impaired glucose tolecare], and diabetes over a longer follow-up period.”
- Siu AL; US Preventive Services Task Force. Screening for abnormal blood glucose and type 2 diabetes mellitus: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2015;163:861-868.