Evaluating CMR

The Aerobics Center Longitudinal Study

In the Aerobics Center Longitudinal Study (ACLS), Katzmarzyk et al. (2) have followed 20,789 non-Hispanic men 20 to 83 years of age for 11.4 years and compared NCEP-ATP III and IDF criteria in predicting CVD mortality. At the beginning of the follow-up, metabolic syndrome prevalence was 19.7% and 30%, respectively, when diagnosed using NCEP-ATP III and IDF screening tools. During the follow-up period, 213 CVD deaths occurred. After adjusting for age and year of examination, the relative risk (RR) for CVD mortality was 2.03 (95% CI, 1.54-2.69) with NCEP-ATP III criteria and 1.86 (95% CI, 1.42-2.44) with IDF criteria. The AROCs for CVD mortality were 0.802 and 0.799 for NCEP-ATP III and IDF criteria, respectively, which are very similar findings. Since the cut-off values for triglycerides, HDL cholesterol, glucose, and blood pressure are the same in NCEP-ATP III and IDF criteria, the authors classified the cohort according to waist circumference thresholds (102cm) and further stratified subjects with the metabolic syndrome based on other risk factors (2 risk factors). As shown in the Figure, CVD death rates increased among waist circumference thresholds and further increased with the presence of two or more risk factors in every category of waist circumference, suggesting that lowering waist circumference thresholds may be an avenue to consider. The authors concluded that the predictive ability of both NCEP-ATP III and IDF criteria was similar and that the public health burden associated with the metabolic syndrome is considerable, regardless which metabolic syndrome criteria are used.