Issue 138 Item 1 Study Finds Hormone Therapy Reduces the Risk of Diabetes by 35%

Hormone therapy reduces the risk of type 2 diabetes in postmenopausal women who have heart disease. But no one, including the study’s authors, are suggesting that hormone replacement therapy (HRT) be prescribed to reduce that risk. Rather, the report, which appears in this week’s issue of the Annals of Internal Medicine, should trigger additional research, experts say.

In the study, Dr. Alka Kanaya, an assistant professor of medicine at the University of California at San Francisco School of Medicine, and her colleagues found that HRT, including estrogen and progestin, reduced the incidence of diabetes by 35 percent during the four-year follow-up in women who had undergone natural menopause and who already had heart disease.

In the new study, Kanaya and her co-researchers zeroed in on a subset of women from the trial known as HERS (Heart and Estrogen/progestin Replacement Study), in which 2,763 women with documented heart disease were assigned to take HRT or a placebo. The main HERS conclusion, that HRT did not help prevent second heart attacks, was released in 1998.

In the newer study, Kanaya and her colleagues focused on the 2,029 women in the HERS trial who were free of diabetes at the outset. These women took either HRT or a placebo each day.

After four years, 160 of the women developed diabetes — 62, or 6.2 percent, of those on HRT and 98, or 9.5 percent, of those on a placebo.

"We found that in [these] women with coronary disease, HRT reduces the incidence of diabetes by 35 percent," says Kanaya. The reduction held, she says, after controlling for such risk factors as obesity, which boosts the chances of getting Type 2 diabetes.

"The conclusion is that this is a scientifically interesting finding that needs to be confirmed, and that the risk of hormone therapy outweighs the benefits and that it’s premature to recommend the use of hormone therapy to prevent diabetes," she adds.

Last summer, a national trial evaluating the benefits of HRT in healthy women was halted after experts determined women taking HRT were at increased risk for strokes and heart attacks but decreased risk for osteoporosis and colon cancer.

"Our feeling is that HRT has a direct effect on the liver, and how the liver processes glucose," Kanaya says. "It’s almost a protection against having too much glucose produced by the liver."
The new study, “Glycemic Effects of Postmenopausal Hormone Therapy,” is published in the January 6 issue of the Annals of Internal Medicine and was funded in part by the Department of Health and Human Services.