The Food and Drug Administration has approved a variety of hormone therapy products, including pills, patches, and creams, to ease menopausal symptoms. A new study confirms the health risks linked to some of these products. Women who use menopausal hormone therapy are twice as likely (or more) to develop lower gastrointestinal bleeding and ischemic colitis than women who do not use these products.

When women enter menopause, their natural hormones (estrogen and progesterone) begin to decline resulting in common symptoms: vaginal dryness, insomnia, and hot flashes. Women also undergo long-term biological changes, such as bone loss, beginning in menopause. To address these issues, some women try various remedies to help them remain healthy and active. For most women, the worst symptom is vaginal dryness, which requires ongoing moisturizing treatment and not just on-the-spot sexual lubricant. Natural therapies include vitamin E, chasteberry, and black cohosh, while Replens, an FDA approved over-the-counter treatment, is non-hormonal.

Faced with menopause, other women prefer the more powerful menopausal hormone therapy (MHT).

GI Bleed

However, these treatments come with risks. For the current study, Dr. Prashant Singh, a resident physician in internal medicine at Massachusetts General Hospital, and his colleagues studied two intertwined issues linked to hormone therapy: gastrointestinal bleeding and ischemic colitis. They conducted a survey of 73,863 women, comparing episodes of gastrointestinal (GI) bleeding among current menopausal hormone therapy users, past users, and those who never used these products. After crunching the numbers, the trends became clear.

Current users have about a 50 percent increased risk of experiencing an episode of major GI bleeding, compared to women who have never used this therapy. Current users also were more than twice as likely to experience ischemic colitis and lower GI bleeding, the researchers say. Ischemic colitis, which is a block in the blood flow to the large intestine, sometimes causes blood vessels to clot; this, in turn, leads to gastrointestinal mucosa dying which then causes lower bleeding in the GI tract.

No difference was found in the occurrence of upper GI bleeding when current users were compared to never users. Singh noted the higher risk of bleeding in the lower GI tract than in the upper is due to the fact that fewer blood vessels supply the lower intestines, so clotting there has much greater impact.

The researchers also investigated major GI bleeding episodes and treatment duration. They found the longer the treatment was taken, the more likely the chance of a major gastrointestinal bleed. Interestingly, past users did not have a more significant risk of GI bleeding than never users. Discontinuing hormone therapy, then, should promptly end all bleeding risks.

"We know that estrogen and progesterone, the two hormones involved in menopausal hormone therapy, induce blood clotting, but we didn't know whether they caused gastrointestinal bleeding," Singh stated in a press release. "This study confirms our speculation that hormonal therapy increases the risk, especially in the lower GI tract."

Source: Boylan MR, Singh P, Khalili H, et al. Menopausal Hormone Therapy Is Associated with Increased Risk of Lower Gastrointestinal Bleeding. Gastroenterology. 2015.