The effect of tibolone on cardiac flow in postmenopausal women with non-insulin dependent diabetes mellitus

Objective: Postmenopausal women with non-insulin dependent diabetes (NIDDM) are frequently obese, hypertensive and hyperlipidaemic and hence at particular risk of coronary heart disease (CHD). They might therefore benefit from menopausal therapy. In view of the fact that oestrogen replacement increases cardiac flow but not limb flow whilst tibolone dilates forearm flow in healthy postmenopausal women, a study was undertaken to evaluate the effects of tibolone on cardiac flow in postmenopausal women with NIDDM. Design: A prospective 12 months before/after intervention study. Patients: 15 postmenopausal women (mean age 58.36 +/- 1.25 years; mean duration of menopause 115.20 +/- 13.97 months; mean BMI: 26.22 +/- 1.02) with NIDDM (mean duration of diabetes 106.07 +/- 15.66 months). Measurements: Cardiac flow was measured every 6 months for 1 year by pulsed Doppler echocardiography. The parameters assessed were: stroke volume (SV), cardiac output (CO), ejection fraction (EF), pre-ejection time (PEP), ejection time (ET), peak systolic flow velocity (PFV), acceleration time (AT), flow velocity integral (FVI), mean acceleration (MA), early diastolic filling time (Ei), atrial filling time interval (Ai), peak velocity of the early diastolic filling (E) and peak velocity of the early atrial filling (A). Blood pressure was also recorded during Doppler echocardiography. Results: Stroke volume, cardiac output and ejection fraction increased significantly after 6 months. There was also a significant increase in peak flow velocity (PFV), flow velocity integral (FVI) and mean acceleration (MA) together with a significant increase in early diastolic filling time (Ei) and peak velocity of the early diastolic filling (E). Blood pressure was unchanged throughout the 12-month study period. Conclusion: The significant increase in stroke volume, cardiac output and flow velocity over the aortic valve parallel the effects of oestrogens in healthy postmenopausal women. The fact that tibolone improved left ventricular relaxation suggests the drug might help prevent or at least defer the development of cardiac dysfunction in diabetic women. (C) 1997 Elsevier Science Ireland Ltd.