Effect of combination hormone replacement therapy on ambulatory blood pressure and arterial stiffness in diabetic postmenopausal women

Abstract

Background: Diabetes mellitus negates the premenopausal gender benefit with respect to coronary artery disease. Whether hormone replacement therapy (HRT) offers any cardiovascular advantage to diabetic postmenopausal women is not known. Diabetic subjects have increased vascular load and abnormal 24-h blood pressure (BP) profiles. Hormone replacement therapy has been shown to improve indexes of arterial load in nondiabetic postmenopausal women as well as to restore circadian variation in BP. This aim of this study, therefore, was to determine prospectively whether HRT improved arterial stiffness and 24-h ambulatory BP profile in diabetic postmenopausal women. Methods: Twelve diabetic postmenopausal women were studied. Six subjects were also hypertensive. Vascular load was characterized by carotid arterial pulse waveform analysis to calculate central augmentation index. All subjects also underwent 24-h BP monitoring. Subjects were studied before commencement of HRT and were then randomized to two groups. The first group was observed for 6 months and then given 2 months of estrogen alone, followed by 4 months of combination estrogen with progestin. The second group received the HRT regimen first, then were restudied after 6 months off HRT. Results: The HRT did not affect either clinic or ambulatory BP. There were no changes in indexes of vascular load or pulse pressure, an indirect measure of arterial stiffness. There was a low rate of circadian variation in 24-h BP at baseline (55%), which was unaltered by HRT. Conclusions: The HRT was well tolerated. Despite evidence for a beneficial effect of HRT on indexes of arterial load and ambulatory BP previously reported in normal subjects, we found no change in this cohort of diabetic postmenopausal women.