Screening for type 2 diabetes mellitus: a systematic review for the U.S. Preventive Services Task Force

Area of Science:

• Preventive medicine
• Endocrinology
• Public health

Background:

• Screening for type 2 diabetes mellitus (T2DM) enables early detection of asymptomatic cases, impaired fasting glucose (IFG), and impaired glucose tolerance (IGT).
• Early identification and treatment of T2DM, IFG, or IGT may lead to improved patient outcomes.

Purpose of the Study:

• To conduct an updated systematic review of evidence on diabetes screening in adults.
• To inform the U.S. Preventive Services Task Force (USPSTF) guidelines on diabetes screening.

Main Methods:

• Systematic review of randomized controlled trials, observational studies, and previous USPSTF reviews.
• Searches of Cochrane databases and MEDLINE from 2007 to October 2014.
• Independent data abstraction and quality assessment by two investigators.

Main Results:

• Two trials showed no significant 10-year mortality benefit from diabetes screening compared to no screening.
• Sixteen trials consistently demonstrated that treatment of IFG or IGT delayed progression to T2DM.
• Most treatments for IFG/IGT did not impact all-cause or cardiovascular mortality, except for lifestyle modification, which showed benefits after 23 years in one trial.

Conclusions:

• Current evidence indicates that diabetes screening does not improve 10-year mortality rates.
• Further research is required to establish the efficacy of treatments for screen-detected diabetes.
• Interventions for IFG and IGT are effective in delaying the onset of T2DM.