Vasodilation in resistance arteries is related to the apolipoprotein B/A1 ratio in the elderly – The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study

Abstract 

Background

Recent studies have shown the apolipoprotein B to apolipoprotein A1 ratio (apoB/A1) to be superior to LDL-cholesterol measurements to predict cardiovascular events.

The present study aims to relate apoB/A1 to endothelium-dependent vasodilation, an early marker of atherosclerosis, in the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study.

Methods and results

In this population-based study, 1016 subjects aged 70 years were evaluated by the invasive forearm technique with acetylcholine (EDV), brachial artery ultrasound to assess flow-mediated vasodilation (FMD) and pulse wave analysis with a beta-2 receptor agonist challenge, terbutaline. EDV and the pulse wave response, but not FMD, were related to apoB/A1 levels (r=−0.11, p=0.0038 for EDV, r=−0.16, p<0.0001 for the pulse wave analysis and r=0.01, p=0.65 for FMD). Neither LDL-cholesterol, nor non-HDL-cholesterol, was significantly related to the measurements of endothelium-dependent vasodilation.

Also endothelium-independent vasodilation (EIDV) evaluated by the invasive forearm technique with sodium nitroprusside was related to apoB/A1 levels (r=−0.12, p<0.0016).

Conclusion

The apoB/A1 levels, but not LDL-cholesterol, were inversely related to endothelium-dependent vasodilation evaluated by EDV and pulse wave analysis, but not by FMD. Also EIDV showed the same pattern, suggesting a general deterioration in vasoreactivity mainly in resistance arteries in elderly subjects with high apoB/A1 levels.

Keywords: Lipids, Apolipoprotein, Endothelium, Vasodilation