Conclusions HbA1c is neither sensitive nor specific for detecting pre‐diabetes ; fasting glucose is specific but not sensitive .
Interventions in people classified through screening as having pre‐diabetes have some efficacy in preventing or delaying onset of type 2 diabetes in trial population s. As screening is inaccurate , many people will receives an incorrect diagnosis and be referred on for interventions while others will be falsely reassured and not offered the intervention .
These findings suggest that “ screen and treat ” policies alone are unlikely to have substantial impact on the worsening epidemic of type 2 diabetes .
& NA ; Objectives To assess diagnostic accuracy of screening tests for  pre‐diabetes  and efficacy of interventions ( lifestyle or metformin ) in preventing onset of type 2 diabetes in people with pre‐diabetes .
Optimal hemoglobin A1C Cutoff Value for Diagnosing type 2 diabetes mellitus in Korean adults.
Commonly used tests for the diagnosis of diabetes include measurements of fasting plasma glucose levels and the oral glucose tolerance test ( OGTT ) . Recently , a hemoglobin A1C ( A1C ) level of 6.5 % has been included as a criterion for diabetes diagnosis by the American Diabetes Association . We aim ed to determine appropriate A1C cutoff values for identifying patients with diabetes or prediabetes , including impaired glucose tolerance and impaired fasting glucose among Korean adults and to determine whether these cutoffs vary according to age . We recruited 4616 adults without a history of diabetes from 10 university hospitals . A 75-g OGTT and A1C sampling were performed in all examinees . Pointwise area under the receiver operating characteristic curve was used to evaluate the diagnostic accuracy of the A1C cutoff . An A1C threshold of 6.1 % proved to be the optimal limit for diagnosing diabetes , with 63.8 % sensitivity and 88.1 % specificity . The cutoff value increased with age ( 5.9 % in 18 - 39 years , 6.2 % in 40 - 64 years , and 6.4 % in older than 65 years ) and were similar for men and women . An A1C cutoff of 5.7 % had reasonable sensitivity ( 48.6 % ) and specificity ( 65.7 % ) for the identification of prediabetes . Further prospect i ve studies should be carried out to determine whether the application of age-specific diagnostic criteria is appropriate
Conclusions HbA1c is neither sensitive nor specific for detecting pre‐diabetes ; fasting glucose is specific but not sensitive .
Interventions in people classified through screening as having pre‐diabetes have some efficacy in preventing or delaying onset of type 2 diabetes in trial population s. As screening is inaccurate , many people will receives an incorrect diagnosis and be referred on for interventions while others will be falsely reassured and not offered the intervention .
These findings suggest that “ screen and treat ” policies alone are unlikely to have substantial impact on the worsening epidemic of type 2 diabetes .
& NA ; Objectives To assess diagnostic accuracy of screening tests for  pre‐diabetes  and efficacy of interventions ( lifestyle or metformin ) in preventing onset of type 2 diabetes in people with pre‐diabetes .