Regional and systemic adipose mass and peripheral conduit artery function.

Introduction: Vascular function and metabolic function are inherently coupled. While prior studies have linked body mass index (BMI) and visceral adiposity to reduced FMD, the relationship between whole-body and limb-specific adiposity and vascular function in adults with pre-diabetic levels of insulin resistance remains unclear.

Methods: We assessed body composition (DEXA), insulin resistance (HOMA-IR and Matsuda Index), and brachial artery FMD in 93 pre-diabetic individuals (69 % Female) aged 18-65 with obesity (BMI ≥ 30 kg/m). Data were analyzed with Pearson product-moment correlation coefficients.

Results: FMD was not associated with BMI (r = 0.12, p = 0.24), total body fat (kg) (r = -0.12, p = 0.31), or arm fat (kg) (r = 0.00, p = 0.99). In contrast, there was an inverse correlation between FMD and Waist:Hip ratio (r = -0.24, p = 0.03), total body lean mass (r = -0.32, p = 0.005) and arm lean mass (r = -0.25, p < 0.03). The correlation between FMD and Waist:Hip ratio persisted after adjusting for HOMA-IR (r =  - 0.31, P = 0.01), the Matsuda Index (r =  - 0.31, P < 0.01) and sex (r = -0.35, p = 0.006).

Conclusion: In adults with obesity and insulin resistance, higher visceral adiposity, but not systemic and regional fat mass, is independently associated with impaired vascular function. These findings suggest that visceral fat distribution may have detrimental effects on vascular health, distinct from its impact on insulin sensitivity.