Objective: To determine the feasibility of using either fasting plasma glucose or HbA(1c) to identify individuals in the U.S. population who meet the Diabetes Prevention Program (DPP) criteria for intervention, defined as BMI >/=24 kg/m(2), fasting plasma glucose level 96-125 mg/dl, and 2-h glucose level 140-199 mg/dl in an oral glucose tolerance test (OGTT).
Research design and methods: Analysis of a representative sample of U.S. adults aged 40-74 years with no medical history of diabetes for whom data on height, weight, fasting plasma glucose, HbA(1c), and 2-h plasma glucose during an OGTT were obtained. Sensitivity, specificity, positive predictive value (PPV), and receiver operator characteristic (ROC) curves for fasting glucose and HbA(1c) were determined.
Results: Using BMI <24 kg/m(2) as an initial criterion eliminated 27.2% of U.S. adults from further testing. Of the remaining group, 41.1% did not have to be considered for an OGTT because their fasting glucose level was below or above 96-125 mg/dl. Overall, 10.6% of adults aged 40-74 years without medical history of diabetes met the DPP eligibility criteria for intervention. Among individuals with BMI >/=24 kg/m(2) and fasting glucose level 96-125 mg/dl, applying a fasting plasma glucose cutoff of >/=105 mg/dl excluded 62.5% of this group and resulted in 56.0% of those with 2-h glucose level 140-199 mg/dl in this group being identified, with a specificity of 72.0% and a PPV of 17.1%. Similar values were obtained for an HbA(1c) cutoff value of >/=5.5%.
Conclusions: Using data on BMI and setting cutoff values for fasting glucose and HbA(1c) would greatly reduce the number of individuals who would need to undergo an OGTT while achieving adequate sensitivity, specificity, and PPV.