By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.
The statin drugs - such as pravastatin - are increasingly being used to treat high cholesterol levels and have been shown to prevent heart attacks and strokes. Many people with high cholesterol also have high blood pressure, so the effect of the statins on blood pressure is of great interest.
A study conducted in Sicily has examined this, by taking 25 patients with high cholesterol and high blood pressure and treating them in a double-blind manner with either pravastatin (20 to 40 milligrams a day) or placebo, each for 16 weeks. The total cholesterol fell from (6.29 to 5.28 mmol/L), LDL cholesterol from (4.31 to 3.22), and the HDL cholesterol rose from (1.45 to 1.56), as expected. Blood pressure fell from 149/97 mmHg to 131/91, a change of 8/7 mmHg. The blood pressure response to a physical stressor (immersing the hand in iced water was diminished during pravastatin treatment. The blood level of endothelin, a hormone that makes blood vessels constrict, was also reduced.
Doctor’s comments
This is a gratifying result because of the common coexistence of high blood pressure and high cholesterol. It is likely that this result would apply equally well to the other statins. The reason why the blood pressure-lowering effects of stain drugs were not apparent from the large trials is most likely that most of these trails included mostly patients with normal blood pressure, and that the stains only lower blood pressure when it is high to begin with. The mechanism by which blood pressure is lowered is not clear but is most probably related to the effects on the endothelium, the inner lining of the arteries. The endothelium makes number of hormones, some of which dilate the blood vessels, and others (such as endothelin) constrict them. Cholesterol impairs the normal functioning of the endothelium, which tends to make the blood vessels less able to dilate.
Where it was published
N Glorioso and colleagues. Effect of the HMG-CoA reductase inhibitors on blood pressure in patients with essential hypertension and primary hypercholesterolemia. Hypertension 1999; 34: 1381.
