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 .
A1C Cut Points to Define Various Glucose Intolerance Groups in Asian Indians
OBJECTIVE To determine A1C cut points for glucose intolerance in Asian Indians . RESEARCH DESIGN AND METHODS A total of 2,188 participants without known diabetes were r and omly selected from the Chennai Urban Rural Epidemiology Study . All had fasting plasma glucose ( FPG ) and 2-h postload plasma glucose measurements after a 75-g load and were classified as having impaired fasting glucose ( IFG ) ( American Diabetes Association [ ADA ] criteria , FPG ≥5.5 and < 7 mmol/l , and World Health Organization [ WHO ] criteria , FPG ≥6.1 and < 7 mmol/l ) , impaired glucose tolerance ( IGT ) ( 2-h postload plasma glucose ≥7.8 and < 11.1 mmol/l ) , or diabetes ( FPG ≥7 mmol/l and /or 2-h postload plasma glucose ≥11.1 mmol/l ) . A1C was measured using the Bio-Rad Variant machine . Based on receiver operating characteristic curves , optimum sensitivity and specificity were derived for defining A1C cut points for diabetes , IGT , and IFG . RESULTS Mean ± SD values of A1C among subjects with normal glucose tolerance , IGT , and diabetes were 5.5 ± 0.4 , 5.9 ± 0.6 , and 8.3 ± 2.0 % , respectively ( Ptrend < 0.001 ) with considerable overlap . To identify diabetes based on 2-h postload plasma glucose , the A1C cut point of 6.1 % had an area under the curve ( AUC ) of 0.941 with 88.0 % sensitivity and 87.9 % specificity . When diabetes was defined as FPG ≥7.0 mmol/l , the A1C cut point was 6.4 % ( AUC = 0.966 , sensitivity 93.3 % , and specificity 92.3 % ) . For IGT , AUC = 0.708 ; for IFG , AUC = 0.632 ( WHO criteria ) and 0.708 ( ADA criteria ) , and the A1C cut point was 5.6 % . CONCLUSIONS In Asian Indians , A1C cut points of 6.1 and 6.4 % defined diabetes by 2-h postload plasma glucose or FPG criteria , respectively . A value of 5.6 % optimally identified IGT or IFG but was < 70 % accurate
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 .