Is Progesterone’s Bad Reputation Overblown and Undeserved?

Progesterone’s bad reputation for harming cardiovascular health is overblown, argue the authors of a new study assessing the hormone treatment in postmenopausal women.¹

The therapy deserves another chance when it comes to alleviating hot flashes and night sweats, the study authors suggested, noting that progesterone can ease those common symptoms without causing cardiovascular risk.

The short-term study by the University of British Columbia and Vancouver Coastal Health published this month found progesterone alone does not appear to increase the risk of heart attack or other diseases of the blood vessels. This new finding follows the 2002 Women's Health Initiative Trial, which reported that a combination of estrogen and progestin raised the risk of heart attack, breast cancer, and stroke in women.

"Many women are apprehensive about taking progesterone for hot flashes because of a belief that it carries the same-or even greater-risks than estrogen," said lead author Jerilynn Prior, MD, a professor of endocrinology at the University of British Columbia and head of the Centre for Menstrual Cycle and Ovulation Research. "We have already shown that the benefits of progesterone alone have been overlooked. This study demonstrates that progesterone's risks have been overblown."

The study of 110 healthy postmenopausal women tested the use of oral progesterone against a placebo for 3 months and then calculated changes in blood pressure, cholesterol levels, and each woman’s 10-year risk of heart attack and other blood vessel disease. The results showed no difference between the two treatment arms, the authors reported.

Prior, who notes in a news release that she has continued to prescribe progesterone to treat hot flashes and night sweats in postmenopausal women since 1995, previously published the results of a randomized, placebo-controlled study in 2012 that revealed progesterone reduced the frequency of night seats and hot flashes.²Pertinent Points:
- A new study questions the validity of linking progesterone therapy to increased cardiovascular risk in postmenopausal women.
- Over 3 months, there was no difference in cardiovascular risk in women who received oral progesterone versus those who received placebo.

References:

1. Prior JC, Elliott TG, Norman E, et al. Progesterone therapy, endothelial function and cardiovascular risk factors: a 3-month randomized, placebo-controlled trial in healthy early postmenopausal women. PLoS One. 2014;9:e84698.
2. Prior JC, Hitchcock CL. Progesterone for hot flush and night sweat treatment-effectiveness for severe vasomotor symptoms and lack of withdrawal rebound Gynecol Endocrinol. 2012;28(suppl 2):7-11.