Increased visceral fat accumulation modifies the effect of insulin resistance on arterial stiffness and hypertension risk

Abstract

Background and aims: Both insulin resistance (IR) and visceral adipose tissue (VAT) are related cardiometabolic risk factors; nevertheless, their joint effect on endothelial functionality is controversial. This study aims to evaluate the joint effect of IR and VAT on endothelial functionality using the pulse-waveform analysis and explore the mediating role of VAT on the effect of IR on arterial pressure, arterial stiffness and incident arterial hypertension.

Methods and results: We measured VAT (n = 586) using two methods (dual-energy X-ray absorptiometry and a clinical surrogate), arterial stiffness (with pulse-waveform velocity), and IR (using three methods: HOMA2-IR (n = 586), a frequently sampled intravenous glucose tolerance test (n = 131) and euglycemic hyperinsulinemic clamping (n = 97)) to confirm the mediator effect of IR on VAT. The incidence of arterial hypertension attributable to the mediating effect of IR related to VAT was evaluated using a prospective cohort (n = 6850). Adjusted linear regression models, causal mediation analysis, and Cox-proportional hazard risk regression models were performed to test our objective. IR and VAT led to increased arterial stiffness and increased blood pressure; the combination of both further worsened vascular parameters. Nearly, 57% (Δ_E→MY 95% CI: 31.7-100.0) of the effect of IR on altered pulse-wave velocity (PWV) analysis was mediated through VAT. Moreover, VAT acts as a mediator of the effect of IR on increased mean arterial pressure (Δ_E→MY 35.7%, 95% CI: 23.8-59) and increased hypertension risk (Δ_E→MY 69.1%, 95% CI: 46.1-78.8).

Conclusion: VAT acts as a mediator of IR in promoting arterial stiffness and arterial hypertension. Both phenomena should be targeted to ameliorate the cardiometabolic risk.

Keywords: Cardiometabolic risk; Cardiovascular health; METS-VF; VAT.