Primary care screening for individuals with impaired glucose metabolism with focus on impaired glucose tolerance

• Three questions about heredity, BMI and hypertension are predictive for IGT.
• These questions used in an advertisement recruits individuals prone to perform lifestyle changes.
• Using HbA1c with a cut-off of ≥42 mmol/mol for screening leaves most individuals with prediabetes undetected.

AimTo evaluate the utility of three short questions (the Skövde Form) combined with a random plasma glucose, and HbA1c as alternative tools for detection of individuals with impaired glucose metabolism (IGM), and particularly impaired glucose tolerance (IGT).MethodsThree questions concerning BMI ≥ 25 kg/m2, heredity for type 2 diabetes, and known hypertension were asked in a random population of 573 individuals. All with two positive answers or one positive answer and a random plasma glucose >7.2 mmol/l were invited for an oral glucose tolerance test and an HbA1c examination. FINDRISC was completed for comparison.ResultsThe positive predictive value (PPV) for IGM, using the Skövde Form, was 31% while sensitivity and specificity were 59% and 73%, respectively. Corresponding values for IGT were 11%, 50% and 69%. Using HbA1c ≥ 42 mmol/mol, the PPV for IGM was 64% while sensitivity and specificity were 28% and 97%, respectively. The corresponding values for IGT were 15%, 16% and 94%.ConclusionThe Skövde Form combined with a random plasma glucose may be used as an alternative tool for detection of individuals with IGM and IGT in particular. HbA1c may be used to identify individuals with type 2 diabetes but fails to detect most individuals with prediabetes.