Higher Appendicular Skeletal Muscle Mass to Visceral Fat Area Ratio Associated With Reduced Risk of Prediabetes

The appendicular skeletal muscle mass to visceral fat area ratio (SVR) reflects the interplay between muscle mass and fat distribution and is increasingly recognized as an indicator of metabolic health. However, its association with prediabetes remains unclear. Therefore, this study aimed to investigate the relationship between SVR and prediabetes.

Data from 4195 participants in the 2011-2018 National Health and Nutrition Examination Survey (NHANES) were analysed using a cross-sectional design. Weighted logistic regression and restricted cubic splines (RCS) were applied to assess the association between SVR and prediabetes. The diagnostic performance of SVR versus body mass index (BMI) and muscle-to-fat ratio (MFR) was compared using weighted receiver operating characteristic curves. Mediation analysis was performed to explore potential indirect associations.

Higher SVR was significantly associated with reduced risk of prediabetes (adjusted OR 0.24; 95% CI: 0.19-0.31). SVR exhibited a nonlinear relationship with prediabetes, with the inflection point of 0.334 kg/cm² for males and 0.199 kg/cm² for females. Notably, SVR demonstrated superior diagnostic performance compared to BMI and MFR, with an area under the curve of 0.653, 0.614 and 0.605 in males and 0.689, 0.651 and 0.619 in females, respectively. Moreover, SVR appeared to be more strongly associated with isolated impaired glucose tolerance than with isolated impaired fasting glucose, consistent with its stronger inverse association with 2-h oral glucose tolerance test glucose (β = -0.44, 95% CI: -0.52 to -0.36) than with fasting glucose (β = -0.12, 95% CI: -0.14 to -0.10). Mediation analysis indicated that homeostatic model assessment for insulin resistance explained 51.08% of the total association.

SVR showed a significant nonlinear association with prediabetes, with gender-specific diagnostic thresholds. Moreover, it demonstrated superior diagnostic capability compared to BMI and MFR for identifying prediabetes.