Association of Visceral Fat Mass Index with Diabetes and Vascular Complications: NHANES 2011–2018 Cross-Sectional Study

Background: Visceral fat mass index (vFMI), a key visceral obesity marker, is linked to insulin resistance and cardiovascular impairment. This study examined the relationship between vFMI, people living with diabetes, and its vascular complications. Methods: Data from NHANES (2011–2018) were used, including participants aged 18 years and older. Multivariable logistic regression models examined associations between vFMI and diabetes, diabetic nephropathy (DN), and cardiovascular disease (CVD). Result: A total of 4,847 participants were included, comprising 2,469 (50.9%) males and 2,378 (49.1%) females, with a mean age of 40 years. The prevalence of diabetes, DN, and CVD was 11.6% (567), 2.8% (136), and 4.3% (208), respectively. Participants in the highest vFMI quartile had a markedly higher risk of diabetes [odds ratio (OR): 5.85, 95% confidence interval (CI): 3.25 to 10.55], DN (OR: 2.84, 95% CI: 0.89 to 9.08), and CVD (OR: 2.55, 95% CI: 1.10 to 5.93) versus the lowest quartile. Nonlinear regression identified critical thresholds for log-transformed vFMI, beyond which risks sharply increased: 0.252 for diabetes and 0.241 for DN. Subgroup analysis showed stronger associations in younger participants (≤40 years), those with lower triglyceride levels, and those with higher β-cell function. Conclusion: Higher vFMI correlates with greater prevalence of diabetes and related complications, indicating that visceral fat plays a critical role in their development.