• DOI:10.1067/MHJ.2002.123145
• Corpus ID: 22257881

A novel mechanism for the beneficial vascular effects of high-density lipoprotein cholesterol: enhanced vasorelaxation and increased endothelial nitric oxide synthase expression.

@article{Kuvin2002ANM,
  title={A novel mechanism for the beneficial vascular effects of high-density lipoprotein cholesterol: enhanced vasorelaxation and increased endothelial nitric oxide synthase expression.},
  author={Jeffrey T. Kuvin and Maria E. R{\"a}met and Ayan R. Patel and Natesa G. Pandian and Michael E. Mendelsohn and Richard H Karas},
  journal={American heart journal},
  year={2002},
  volume={144 1},
  pages={
          165-72
        }
}

• J. Kuvin, Maria E. Rämet, +3 authors R. Karas
• Published 1 July 2002
• Medicine, Biology
• American heart journal

BACKGROUND
Low levels of high-density lipoprotein (HDL) cholesterol increase the risk of coronary artery disease (CAD), and recent clinical studies suggest that interventions in low-HDL patients are beneficial. The purpose of this study was to examine the effect of increased HDL levels on endothelium-dependent vasodilation.

METHODS
We studied patients with CAD with a low-density lipoprotein (LDL) level of <100 mg/dL. Patients with an HDL level of < or =36 mg/dL were treated with niacin (n = 11), and patients with an HDL level of >36 mg/dL were followed as controls (n = 10). Baseline and 3-month follow-up studies of flow-mediated dilation (FMD) and blood lipid levels were obtained.

RESULTS
HDL levels increased from 30.1 +/- 1.2 to 40.5 +/- 1.2 mg/dL in the niacin-treated patients (P <.001) but remained unchanged in the control patients. At baseline, FMD was impaired in both the treated (6.5% +/- 1%) and the control (7.3% +/- 1%) patients compared with 10 healthy subjects (16% +/- 2%, P <.01). After 3 months, FMD improved in the niacin-treated patients (11.8% +/- 1%, P =.001) but remained unchanged in the control patients (6.2% +/- 1%). Exposure of cultured human vascular endothelial cells to HDL in vitro enhanced expression of endothelial nitric oxide synthase (eNOS), as shown by immunoblotting.

CONCLUSIONS
In patients with CAD and well-controlled LDL levels, elevation of HDL with niacin improves endothelial function. HDL increases eNOS protein expression in cultured vascular endothelial cells. Taken together, these observations suggest that HDL-mediated increases in eNOS expression may contribute to the observed enhancement in vasorelaxation and thus support a previously unrecognized mechanism for the beneficial cardiovascular effects of HDL.