Predictive value of cardiometabolic index in chinese adolescents aged 12–18 years old for metabolically unhealthy phenotype in normal weight population

Objective: There are few studies on the predictive value of Cardiometabolic index (CMI) on metabolically unhealthy normal weight (MUNW) phenotype in adolescents. Hence, the aim of this study was to investigate the relationship between CMI and MUNW phenotype in Chinese adolescents and to assess the predictive value of CMI for MUNW phenotype. Design and method: Using stratified cluster sampling method, 1009 adolescents (605 males, 60%) aged 12-18 years old in Ningxia were randomly selected from October 2017 to September 2020 for questionnaire survey, physical measurements, body composition measurements and laboratory examinations. The relationship between MUNW phenotype and CMI was analyzed using binary logistic regression, and the predictive ability of relevant indicators for MUNW phenotype was assessed by constructing receiver operating characteristic (ROC) curves. Results: There were 913 cases of metabolically healthy weight normal (MHNW) phenotype and 96 cases of metabolically abnormal weight normal (MUNW) phenotype. The CMI level of the MUNW phenotype was higher than that of the MHNW phenotype (P<0.001). After adjusting for confounders such as age and gender, the risk of MUNW in the highest quartile group (Q4) of CMI was 3.37 times (95% CI: 1.66-6.83) higher than that of the lowest quartile group (Q1), and the risk of MUNW was at a gradually increasing (P<0.001). The MUNW risk of CMI in male and female students in Q4 group was 3.18 times (95% CI: 1.11-9.14) and 3.90 times (95% CI: 1.45-10.50) higher than that in Q1 group (all P < 0.05). Compared with BMI, TG/HDL-C, WC and WHtR, CMI was the best predictor of MUNW phenotype in both sexes (boys:AUC=0.686,95%CI:0.581∼0.792; girls: AUC=0.696,95%CI: 0.607∼0.785) (P<0.001). Conclusions: CMI is a risk factor for the risk of developing theMUNW phenotype in Chinese adolescents, and CMI has strong predictive efficacy as a valid tool for identifying the MUNW phenotype in a normal weight population.