Metabolic Syndrome and Somatic Composition: A Large Cross-sectional Analysis.

Background/aim: To elucidate the relationship between metabolic syndrome (Mets) and somatic composition [fat mass, fat-free (FF) mass, and fat to fat-free (F-FF) ratio] among health checkup recipients (7,776 males and 10,121 females).

Patients and methods: We classified study subjects into four types considering Japanese criteria for Mets; Type A is for males with waist circumference (WC) <85 cm and females with WC <90 cm, Type B is for males with WC ≥85 cm and females with WC ≥90 cm, but without any metabolic abnormalities, Type C is for males with WC ≥85 cm and females with WC ≥90 cm and one metabolic disorder (pre-Mets), and Type D is Mets. We compared baseline characteristics among types of A, B, C, and D.

Results: F index, FF index, and F-FF ratio showed an increasing trend with increasing risk factors for Mets in both sexes.

Conclusion: This study demonstrates a clear correlation between somatic composition and the severity of metabolic syndrome (Mets). As Mets risk factors increase, fat mass, fat-free mass, and the fat-to-fat-free ratio also rise, indicating that body composition shifts with disease progression. These findings emphasize the need for early intervention, such as exercise and diet, to manage somatic composition imbalances and reduce complications like insulin resistance.