Effects of low- or high-dose hormone therapy on fasting and post-methionine homocysteine levels in postmenopausal women

Abstract

Objective To evaluate the effect of two different hormone therapy (HT) doses on fasting and post-methionine homocysteine levels, an independent risk factor for cardiovascular and thromboembolic diseases.

Methods Forty-eight women in natural postmenopause randomly received calcium 1 mg/day (control group; n = 12) or calcium plus low dose (1 mg estradiol plus 0.5 mg norethisterone; n = 18) or high dose (2 mg estradiol plus 1 mg norethisterone; n = 18) HT in a 6-month randomized, controlled, prospective study.

Results Folate levels did not vary in any group, while levels of vitamin B12 significantly decreased after low- (−12.2 ± 6.6%; p < 0.04) or high-dose HT (−13.9 ± 6.1%; p < 0.01). Fasting homocysteine was reduced by either HT dose in a way that was inversely related to pretreatment homocysteine levels (−0.675x; r = 0.644; p < 0.0001). Modification of post-load homocysteine increase was influenced by the HT dose and inversely related to the homocysteine response to methionine observed at baseline. The regression slope observed with the low-dose HT (−1.637x; r = 0.57; p < 0.02) was significantly steeper (p < 0.001) than that observed with the high-dose HT (−0.304x; r = 0.554; p < 0.03) dose.

Conclusions Low- or high-dose HT similarly influences fasting homocysteine levels. Low-dose HT seems to be more effective than high-dose HT in reducing the post-methionine homocysteine increase.

Key words:

• Homocysteine
• Hormone therapy
• Estrogen
• Progestogen
• Menopause
• Methionine