Do arterial effects of antihypertensive drugs depend on subject's serum cholesterol?

Effects of antihypertensive treatment on large arteries may be influenced by the type of drug and concomitant risk factors such as blood cholesterol. To explore these possibilities we investigated the common carotid artery of 20 subjects with low cholesterol and 19 subjects with high cholesterol, all with essential hypertension, randomly allocated to 3 months of treatment with nitrendipine (20 mg/d) or trandolapril (2 mg/d). Carotid parameters were determined by recording instantaneous pressure (applanation tonometry) and diameter (echotracking device) and by modeling the pressure-diameter loop to obtain the Peterson modulus, stiffness index, measured and isobaric compliances, and wall viscosity. Effects of drugs on carotid parameters did not differ, except on systolic and diastolic diameters (p < 0.01), which increased insignificantly under nitrendipine but decreased (p < 0.01) under trandolapril. Blood cholesterol status did not influence carotid effects of trandolapril, whereas patients with low and high cholesterol treated with nitrendipine exhibited significant differences in drug effects on (a) systolic and pulse pressures (p < 0.05), which decreased in patients with low cholesterol (p < 0.01, p < 0.05) but not in those with high cholesterol; (b) diastolic diameter (p = 0.05), which increased insignificantly in patients with low cholesterol but was unchanged in those with high cholesterol; and (c) wall viscosity (p < 0.01), which decreased in patients with low cholesterol (p < 0.05) but increased insignificantly in those with high cholesterol. Also, wall viscosity change under nitrendipine was positively related to the baseline blood cholesterol ( r = 0.64, p < 0.01). Thus, nitrendipine and trandolapril show noteworthy differences in their effects on the carotid artery, in particular with respect to the status of blood cholesterol, but these differences should be confirmed by larger studies.