Objective: This study assessed the effect of intranasal administration of 17beta-estradiol (Aerodiol) on plasma levels of homocysteine, Vitamin B12 and folate in postmenopausal women.
Methods: In all, 26 symptomatic postmenopausal women who had undergone hysterectomy and oophorectomy at least 12 months previously participated in this 6-month randomized prospective clinical study. Menopause was determined by serum FSH level >30 microIU/ml and serum estradiol concentration <30 pg/ml. Intranasal 17beta-estradiol treatment was given once daily at a standard daily dose of 300 microg to 16 women, and 10 did not receive any treatment.
Results: In the group receiving intranasal 17beta-estradiol, mean (+/-S.D.) plasma homocysteine level decreased significantly from pre-treatment values (from 16.68+/-4.33 to 14.15+/-1.18 nmol/ml, p=0.029) and the mean folate level increased (from 4.11+/-0.80 to 5.64+/-1.87 ng/ml, p=0.012). Vitamin B12 levels showed a tendency towards increasing. In the treated group, significant negative correlations were observed between homocysteine and folate values (r=-0.586, p=0.017) and between homocysteine and Vitamin B12 values (r=-0.672, p=0.004). No significant changes were observed in the untreated group.
Conclusion: The reduction in plasma homocysteine levels observed after 6 months' treatment with intranasal 17beta-estradiol may reflect an alteration in folate and Vitamin B12 homeostasis.