1. Adaptive changes in small arteries may be more closely correlated with pulse pressure than with systolic, diastolic or mean blood pressures in human essential hypertension.
2. An analysis was performed on the structure of small arteries, age and blood pressure measurements obtained from 56 patients with untreated essential hypertension and 56 matched normotensive volunteers to examine the association between age, blood pressure and small artery structural parameters.
3. Essential hypertension was associated with an increase in media thickness and a decrease in lumen diameter, resulting in an increase in media/lumen ratio.
4. There was a significant correlation between age and media/lumen ratio in normotensive volunteers but not in patients with essential hypertension.
5. There was no correlation between any blood pressure and structural parameter in normotensive volunteers.
6. Both diastolic and mean blood pressures in essential hypertension correlated with media/lumen ratio (P < 0.01); systolic blood pressure correlated less well (P < 0.02). However, pulse pressure did not correlate with media/lumen ratio, suggesting that it is not a significant determinant of small artery structure in untreated essential hypertension.