THE EFFECT OF ESTROGEN ON BLOOD-PRESSURE IN HYPERTENSIVE POSTMENOPAUSAL WOMEN

The authors' objectives were to investigate the effect of an oral estr ogen on blood pressure and other cardiovascular risk markers, namely s erum lipid and lipoprotein levels, coagulation and endothelial cell fu nction, in postmenopausal hypertensive women. A randomized, placebo-co ntrolled, crossover study was undertaken in a teaching hospital menopa use clinic and cardiology and metabolic research departments. Twenty p ostmenopausal women with mild hypertension were recruited and randomiz ed to take orally one estrogen tablet (tablets containing 0.6 mg of es tradiol, 0.27 mg of estriol, and 1.4mg of estrone [Hormonin(R), Shire Pharmaceuticals Ltd, Andover, Hants, UK]) daily, for a period of 8 wee ks, followed by 8 weeks of placebo, or vice versa. The main out come m easures were ambulatory blood pressure recordings, fasting lipid and l ipoprotein levels, and coagulation indices. Results showed no signific ant changes in diastolic and systolic blood pressure for patients taki ng estrogen with respect to 24-hour and day and night readings. The me an 24-hour ambulatory blood pressure readings were 135.7 mmHg/83.9 mmH g at baseline, 131.7 mmHg/83.0 mmHg for patients receiving estrogen, a nd 129.9 mmHg/82.8 mmHg for patients receiving placebo. Serum levels o f high-density lipoproteins and apolipoprotein AI increased significan tly by 0.1 mmol/l (p = = 0.005) and 32 mg/dl (p = 0.002), respectively , for patients receiving estrogen, whereas those of low-density lipopr oteins and apolipoprotein B decreased by 0.7 mmol/l (p = 0.0005) and 5 .5 mg/dl (p = 0.04). The only clotting factor significantly affected w as plasminogen, which increased by 13.6% (p = 0.008) for patients unde rgoing active treatment. These results suggest that estrogens may be s afely used in stable hypertensive women with no increase in ambulatory blood pressure. The changes in other risk factors were beneficial and resemble those described in normotensive postmenopausal women.