Hormone replacement therapy (HRT) can reduce diabetes by 35 percent in women with coronary disease, according to a study of more than 2000 women. The authors do not recommend the use of hormones for disease prevention, but instead encourage further study of the effects of estrogen and progestin hormone therapy on metabolic complications.
Principal Investigator Alka Kanaya, MD, led a team in further analysis of data from the Heart and Estrogen/Progestin Replacement Study (HERS). HERS was a randomized, blinded trial led by UCSF to determine the effects of HRT compared with placebo in older postmenopausal women with heart disease.
“The potential benefit to patients for one health outcome needs to be weighed against the risk for others, such as coronary events and breast cancer,” said Kanaya, a UCSF assistant professor of medicine. “But our data allude to important metabolic benefits of HRT that should be studied further,” she said. Current clinical practice guidelines recommend the use of HRT for the short-term relief of menopausal symptoms only.
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.
Some of the HERS participants had existing diabetes and some began the trial with impaired fasting glucose (IFG), a condition in which the blood glucose level is elevated when measured after an overnight fast but is not high enough to be classified as diabetes. Equal proportions of women with diabetes, with IFG, and without diabetes were randomly assigned to HRT or placebo in the trial.
The diabetes researchers evaluated the effect of HRT on fasting glucose levels and on any new diagnoses of diabetes among the HERS participants over four years of follow up. All HERS participants had their fasting glucose levels measured during a baseline exam at the study’s beginning, after the first year of the study, and at the study’s end. Researchers found that a new diagnosis of diabetes was made during the four-year trial in a total of 160 women: 62 women assigned to hormone therapy and 98 on placebo.
The women who received placebo had an increased risk for diabetes which could not be explained by other factors such as weight and waist circumference. The placebo group—both those with and those without diabetes at the study’s beginning—had significant worsening of their fasting glucose measures compared with the women who received HRT. The trend was similar among women with IFG.
HERS was the first randomized, blinded, placebo-controlled trial large enough to detect the effects of hormone therapy on disease outcomes. Research was conducted at outpatient and community settings at 20 United States clinical centers. A total of 2,763 postmenopausal women with coronary heart disease were enrolled in HERS.
Guidelines for the use of HRT underwent dramatic shifts during 2002, when further data from HERS and another trial, the Women’s Health Initiative, demonstrated elevated risks of heart disease and breast cancer among women using post menopausal HRT.
Co-investigators of the new study are David Herrington, MD, Wake Forest University; Eric Vittinghoff, PhD, UCSF; Feng Lin, MS, UCSF; Deborah Grady, MD, MPH, UCSF; Vera Bittner, MD, MSPH, University of Alabama; Jane A. Cauley, DrPH, University of Pittsburgh; and Elizabeth Barrett-Connor, MD, University of California, San Diego.
HERS was funded by Wyeth-Ayerst.