Because the mechanisms of the biological effects of statin and antiotensin converting enzyme inhibitor therapies differ, the vascular responses to these therapies were studied in hypercholesterolemic patients.

Simvastatin, 20 mg, placebo or ramipril, 10 mg, were administered daily for 2 months, with a 2 month washout, to 32 hypercholesterolemic patients. This was a randomized, double-blind, placebo-controlled, crossover in design study.

Simvastatin alone, or in combination with ramipril, significantly changed the lipoproteins, and improved the percentage of the flow-mediated dilator response to hyperemia by 46±48% and by 59±66%, respectively, relative to the baseline measurements (both p<0.001). The plasma malondialdehyde levels were reduced, relative to baseline measurements, by 6±57% (p=0.045) and 13±47% (p=0.045 and p<0.001, respectively) and plasma levels of monocyte chemoattractant protein-1 by 3±27% and by 9±16%, respectively (p=0.113 and p=0.001, respectively). The C-reactive protein were also reduced, relative to baseline measurements, by 17±75% and by 17±37%, respectively (p=0.003 and p=0.001, respectively). However, simvastatin combined with ramipril changed, to a greater extent, but was statistically insignificant, the percentage of the flow-mediated dilator response to hyperemia, and the plasma monocyte chemoattractant protein-1 levels, than simvastatin alone.

Compared with simvastatin alone, the addition of ramipril improved the endothelial function to greater extent, but was statistically insignificant, in hypercholes-terolemic patients.