OBJECTIVE: Our purpose was to assess the effects of estrogen replacement therapy on plasma levels of nitric oxide in postmenopausal women. STUDY DESIGN: The study, designed as a randomized, double-blind placebo-controlled crossover trial, involved 28 healthy postmenopausal women who had previously undergone hysterectomy. Women received either transdermal estradiol (50 g/day) (estradiol group) or placebo (placebo group) for 6 months continuously. At the end of month 6 the treatment allocations were opened, and then the treatments were exchanged for 1 month. The serum concentration of estradiol was measured at baseline before treatment and at the end of months 6 and 7. The plasma concentration of the stable oxidation products of nitric oxide was assessed before treatment and monthly until month 7. RESULTS: The mean baseline concentrations of nitric oxide metabolites in the estradiol and placebo groups were similar (mean and SD: 19+/-4.3 vs 21+/-5.6 micromol/L, respectively). At subsequent measurements from months 1 to 6, the mean concentration of nitric oxide metabolites increased significantly in the estradiol group alone, in which the concentration ranged between 33 6.4 and 36 8.5 micromol/L. At the end of month 7 the mean level of nitric oxide metabolites in women previously treated with estradiol fell to baseline value (19 2.6 micromol/L), whereas in the placebo group the level increased significantly (34 4.4 micromol/L). CONCLUSION:Estrogen replacement therapy induces a sustained increase in plasma levels of nitric oxide in postmenopausal women; the suspension of estrogen replacement therapy is followed by a significant reduction in nitric oxide levels. The results of this study suggest that a nitric oxide-related mechanism may help to explain the cardioprotective effect of estrogen replacement therapy in the postmenopausal period.
RCT Entities:
OBJECTIVE: Our purpose was to assess the effects of estrogen replacement therapy on plasma levels of nitric oxide in postmenopausal women. STUDY DESIGN: The study, designed as a randomized, double-blind placebo-controlled crossover trial, involved 28 healthy postmenopausal women who had previously undergone hysterectomy. Women received either transdermal estradiol (50 g/day) (estradiol group) or placebo (placebo group) for 6 months continuously. At the end of month 6 the treatment allocations were opened, and then the treatments were exchanged for 1 month. The serum concentration of estradiol was measured at baseline before treatment and at the end of months 6 and 7. The plasma concentration of the stable oxidation products of nitric oxide was assessed before treatment and monthly until month 7. RESULTS: The mean baseline concentrations of nitric oxide metabolites in the estradiol and placebo groups were similar (mean and SD: 19+/-4.3 vs 21+/-5.6 micromol/L, respectively). At subsequent measurements from months 1 to 6, the mean concentration of nitric oxide metabolites increased significantly in the estradiol group alone, in which the concentration ranged between 33 6.4 and 36 8.5 micromol/L. At the end of month 7 the mean level of nitric oxide metabolites in women previously treated with estradiol fell to baseline value (19 2.6 micromol/L), whereas in the placebo group the level increased significantly (34 4.4 micromol/L). CONCLUSION: Estrogen replacement therapy induces a sustained increase in plasma levels of nitric oxide in postmenopausal women; the suspension of estrogen replacement therapy is followed by a significant reduction in nitric oxide levels. The results of this study suggest that a nitric oxide-related mechanism may help to explain the cardioprotective effect of estrogen replacement therapy in the postmenopausal period.
Authors: Jennifer C Sullivan; Jennifer L Pardieck; Kelly A Hyndman; Jennifer S Pollock Journal: Am J Physiol Regul Integr Comp Physiol Date: 2009-11-04 Impact factor: 3.619
Authors: Shelley R Salpeter; Judith M E Walsh; Elizabeth Greyber; Thomas M Ormiston; Edwin E Salpeter Journal: J Gen Intern Med Date: 2004-07 Impact factor: 5.128
Authors: Jacqueline K Limberg; Garrett L Peltonen; Rebecca E Johansson; John W Harrell; Jeremy M Kellawan; Marlowe W Eldridge; Joshua J Sebranek; Benjamin J Walker; William G Schrage Journal: Front Physiol Date: 2016-06-08 Impact factor: 4.566