Cholesterol Efflux Capacity Associates with the Ankle-Brachial Index but Not All-Cause Mortality in Patients with Peripheral Artery Disease

Abstract

Background: Cholesterol efflux is an important mechanism by which high-density lipoproteins (HDLs) protect against cardiovascular disease. As peripheral artery disease (PAD) is associated with high mortality rates, mainly due to cardiovascular causes, we investigated whether cholesterol efflux capacity (CEC) of apolipoprotein B (apoB)-depleted plasma, a widely used surrogate of HDL function, may serve as a predictive marker for mortality in this patient population. Methods: In this prospective single-center study (median follow-up time: 9.3 years), apoB-containing lipoproteins were precipitated from plasma of 95 patients with PAD and incubated with J744-macrophages, which were loaded with radiolabeled cholesterol. CEC was defined as the fractional radiolabel released during 4 h of incubation. Results: Baseline CEC was lower in PAD patients that currently smoked (p = 0.015) and had a history of myocardial infarction (p = 0.011). Moreover, CEC showed a significant correlation with HDL-cholesterol (p = 0.003) and apolipoprotein A-I levels (p = 0.001) as well as the ankle-brachial index (ABI, p = 0.018). However, CEC did not differ between survivors and non-survivors. Neither revealed Kaplan–Meier and Cox regression analyses any significant association of CEC with all-cause mortality rates. Conclusion: Taken together, CEC is associated with ABI but does not predict all-cause mortality in patients with PAD.

Inverse Correlation of Cholesterol Efflux Capacity with Peripheral Plaque Volume Measured by 3D Ultrasound

“…Our research evaluated the primary role of HDL in clearing free cholesterol from the plasma membrane of macrophages. To this end, we used a cholesterol efflux assay that was previously applied in several clinical studies [18,42]. According to the correlation between HDL-C and CEC, the test employed in this study mostly captured HDL-C-mediated CEC [1].…”