Prevalence of undiagnosed metabolic syndrome in a population of adult asymptomatic subjects

BackgroundTo evaluate in the general population the prevalence of undiagnosed metabolic syndrome (MS), defined according to the National Cholesterol Education Program (NCEP) and International Diabetes Federation (IDF) criteria.MethodsA population-based cross-sectional study of 1175 asymptomatic adults in North-Western Italy.ResultsThe prevalence of undiagnosed MS was 16.4% (95% CI = 14.4–18.6) (NCEP) and 28.0% (25.4–30.6) (IDF), respectively, 5.2% (3.6–7.3) and 8.9% (6.6–11.3) in normal-BMI and 26.6% (23.3–30.2) and 45.3% (41.3–49.2) in overweight/obese individuals. Of the total cohort, 52% were overweight/obese and they accounted for 85% of the cases of MS; a further 19% were normal weight with light physical activity and accounted, respectively, for 12% (NCEP) and 13% (IDF) of the cases. Only 25% (NCEP) and 14% (IDF) of participants showed no component of the MS (respectively, 40 and 26% of those not-overweight and 11 and 3% of those overweight/obese).ConclusionsMore than 97% of unknown MS cases would be identified among apparently healthy individuals when overweight/obese, and normal-BMI subjects with low physical activity were screened. These two criteria might, therefore, be used to prioritise screening programmes in asymptomatic subjects, since even apparently healthy individuals, who are not-overweight, frequently show one or more metabolic abnormalities, whose co-existence has been demonstrated to be hazardous.