The presence of abdominal obesity is associated with changes in vascular function independently of other cardiovascular risk factors

Abstract 

Background

Because of the strong association between abdominal obesity (AO) and other cardiovascular risk factors, it has been difficult to determine which changes in vascular function are directly related to this condition. Our objective was to evaluate the changes in ex-vivo vascular reactivity, circulating levels of adipokines and inflammatory markers associated with the presence of AO in subjects who underwent coronary artery bypass graft (CABG) controlling by the presence of other cardiovascular risk factors.

Methods

Subjects scheduled for a CABG with (n=17) and without (n=17) AO (defined as a waist circumference ≥90 cm for male or ≥80 cm for female) whom were matched by several cardiovascular risk factors, were included in the study. Lipid profile and plasma levels of glucose, insulin, leptin, adiponectin and inflammatory markers were measured. Internal mammary artery segments were used for ex-vivo vascular reactivity experiments and morphometry.

Results

Leptin concentrations were higher and adiponectin concentrations were lower in subjects with AO. No differences were observed in other biochemical or clinical parameters between the groups. No correlation between waist circumference, HOMA index and inflammatory markers were observed. Endothelium-dependent relaxation to acetylcholine was lower, and contractile responses to angiotensin-II were higher in subjects with AO. These changes were not related to differences in vascular morphometry.

Conclusion

In subjects with severe coronary disease, the presence of AO was associated with leptin/adiponectin imbalance, decreased endothelium-dependent relaxation and an enhanced response to angiotensin-II. These changes occurred independently of other cardiovascular risk factors including insulin resistance and levels of inflammatory markers.

Keywords: Abdominal obesity, Leptin, Adiponectin, Vascular reactivity, Inflammation, Coronary artery bypass graft, Internal mammary artery