Cardiometabolic index: a new tool for screening the metabolically obese normal weight phenotype

People with the metabolically obese normal weight (MONW) phenotype are considered as an extremely high-risk group for unfavorable health consequences, but they are frequently undetected due to deceptive body mass index (BMI) and complex assessment. This study aimed to explore the clinical usefulness of cardiometabolic index (CMI) in identifying MONW individuals.

This cross-sectional study involved a total of 47,683 normal-weight subjects aged ≥ 18 years. Participants underwent anthropometrics, routine biochemical tests, and questionnaires for a full evaluation of the metabolic profile. The odds ratio (OR) of CMI and MONW phenotype was determined by the Logistic regression models and the diagnostic accuracy of CMI was evaluated by the receiver operating characteristic (ROC) curve analysis.

The prevalence of MONW phenotype was 11.0%. After multivariate adjustment, the ORs for MONW in the highest compared with the lowest quartile of CMI was 71.20 (95% CI 55.19-91.86), and 1-SD increment of CMI brought a 54% additional risk. In ROC analysis, compared with BMI and waist circumference, CMI showed superior performance for identifying MONW individuals with an AUC of 0.853 (95% CI 0.847-0.860) in men and 0.912 (95% CI 0.906-0.918) in women, respectively. Moreover, CMI exhibited the highest diagnostic accuracy in younger age groups (aged 18-34 for men; aged 18-34 and 35-44 for women), in which AUCs surpassed 0.9 in both sexes.

CMI could be served as a valuable indicator to identify MONW phenotype of Chinese adults, particularly for young people.