The “metabolic syndrome” is less useful than random plasma glucose to screen for glucose intolerance

Abstract 

Aims

To compare the utility of metabolic syndrome (MetS) to random plasma glucose (RPG) in identifying people with diabetes or prediabetes.

Methods

RPG was measured and an OGTT was performed in 1155 adults. Test performance was measured by area under the receiver-operating-characteristic curve (AROC).

Results

Diabetes was found in 5.1% and prediabetes in 20.0%. AROC for MetS with fasting plasma glucose (FPG) was 0.80 to detect diabetes, and 0.76 for diabetes or prediabetes—similar to RPG alone (0.82 and 0.72). However, the AROC for MetS excluding fasting plasma glucose was lower: 0.69 for diabetes (p<0.01 vs. both RPG and MetS with FPG), and 0.69 for diabetes or prediabetes. AROCs for MetS with FPG and RPG were comparable and higher for recognizing diabetes in blacks vs. whites, and females vs. males. MetS with FPG was superior to RPG for identifying diabetes only in subjects with age <40 or BMI <25.

Conclusions

MetS features can be used to identify risk of diabetes, but predictive usefulness is driven largely by FPG. Overall, to identify diabetes or prediabetes in blacks and whites with varying age and BMI, MetS is no better than RPG—a more convenient and less expensive test.

Abbreviations: AGI₁₁₀, any glucose intolerance₁₁₀ (diabetes or IGT or IFG_110–125), ARIC, Atherosclerosis Risk in Communities study, AROC, area under the ROC curve, DETECT-2, “international data pooling collaboration specifically addressing issues related to screening for type 2 diabetes”, dysglycemia, type 2 diabetes or IGT or IFG₁₁₀, EPIC-Norfolk, European Prospective Investigation of Cancer-Norfolk, FPG, fasting plasma glucose, GCRC, General Clinical Research Center, Health ABC, Health, Aging, and Body Composition study, HDL, high density lipoprotein, IFG, impaired fasting glucose, IFG₁₁₀ or IFG_110–125, IFG with fasting plasma glucose 110–125mg/dl, IGT, impaired glucose tolerance, NCEP, National Cholesterol Education Program, NHANES-III, National Health and Nutrition Examination Survey III, Prediabetes, IGT and/or IFG₁₁₀, ROC, receiver-operating-characteristic, RPG, random (nonfasting) plasma glucose, T2DM, type 2 diabetes mellitus, WHO, World Health Organization

Keywords: Screening, Type 2 diabetes, Prediabetes, Impaired glucose intolerance, Impaired fasting glucose