Abstract: 【Objective】 To analyze the association of fat mass index (FMI) and metabolic syndrome (MS)

and investigate the optimal cut-off points and predictive ability of FMI in screening for MS among men and woman in Guangzhou. 【Methods】 A cross -sectional study was implemented in the examination population aged 20 years and above

who participated in the annual check -ups in Guangdong General Hospital. Questionnaire

anthropometric measurements

blood tests and body composition analysis were performed. Body fat mass was measured by bioelectric impedance analysis. FMI was calculated

and divided into separate quartiles for men and women. The MS was defined both by the diagnostic criteria of the International Diabetes Federation (IDF) and Joint Committee for Developing Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults (JCDCG). The characteristics of cardiovascular risk factors among FMI groups were compared by univariate methods. The association between the sex -specific FMI quartile and MS was examined using binary logistic regression. Receiver operating characteristic (ROC) curve was performed to identify the sex -specific FMI cut -offs and predictive values in screening for MS. 【Results】 A total of 890 subjects

with 502 men and 388 women were analyzed. After adjustment for relative confounders

the presence of MS and FMI quartiles revealed a dose -response relationship in both sexes. The cut -off point of FMI for MS by IDF criteria was 5.50 kg/m2 for men and 7.99 kg/m2 for women with the corresponding area under the curve (AUC) of 0.865 (0.832 ~ 0.893) and 0.869 (0.832 ~ 0.901)

and 5.33 kg/m2 for men and 7.99 kg/m2 for women by JCDCG criteria with the AUC of 0.867 (0.834 ~ 0.895) and 0.899 (0.864 ~ 0.927)

respectively. The AUCs of FMI for MS were significantly greater than that of body fat percentage (BF%) by both IDF and JCDCG criteria in both sexes. 【Conclusion】 Higher FMI levels were closely associated with the presence of MS. FMI seems to be a better screening tool for evaluating MS than BF% in men and women.