Diabetic Women on Hormone Replacement Therapy Have Better Glycemic and Lipid Profiles

BUFFALO, N.Y. -- Diabetic women who use hormone replacement therapy (HRT) were more likely to have their blood glucose under control, and have lower cholesterol levels than women who never used hormone therapy, a study by University at Buffalo epidemiologists has found.

Nondiabetic women who were using HRT also had lower total cholesterol levels, as well as higher levels of beneficial cholesterol, the study results showed.

The study, published in the current issue of Diabetes Care, adds yet another twist to the murky risks-benefits scenario surrounding HRT.

The federal government suspended a nationwide clinical trial of HRT in July, citing, among other concerns, that the combination of estrogen and progesterone used in the trial did not protect against cardiovascular disease as expected.

Yet, the UB researchers found that HRT had a positive effect on two important risk factors for heart disease -- blood levels of fats and glucose -- in a population-based study of 2,786 diabetic and non-diabetic postmenopausal women between the ages of 40 and 74.

Carlos Crespo, Ph.D., associate professor of social and preventive medicine in the UB School of Medicine and Biomedical Sciences and lead author on the study, noted that the national HRT clinical trial did not include women with diabetes and that scientists haven't researched the benefits or risks of hormone replacement in this group.

"Although there may be some risk in using certain types of HRT among certain women, there might be a segment of women who would be better off using HRT," Crespo said. "These findings indicate that diabetic women may be one such segment."

The study, based on data from the Third National Health and Nutrition Examination Survey (NHANES III), compared lipid profiles, glucose and insulin levels and concentrations of selected blood components known to increase or decrease the risk of heart disease in diabetic and nondiabetic women. Participants were grouped into one of three HRT-use categories: current, previous or never.

Results showed that diabetic women on HRT had significantly lower fasting levels of total cholesterol compared to diabetic women who were previous or never users: 225 mg/dl, 247 mg/dl and 241 mg/dl, respectively. The difference in fasting glucose levels among diabetic women according to HRT status were equally significant: 112 mg/dl for current users compared to 151 mg/dl and 154 mg/dl for previous and never users.

Among nondiabetic women, current HRT users had significantly higher levels of beneficial high-density lipoprotein (HDL) than previous or never users -- 64 mg/dl, 57 mg/dl and 55 mg/dl, respectively.

HRT also appeared to have a beneficial effect on several additional markers of heart health and glycemic control in both diabetic and nondiabetic women:

o Fibrinogen, a protein associated with increased risk of coronary heart disease, stroke and peripheral artery disease through its role in blood clotting and platelet aggregation was lower among HRT users in both groups of women compared to never users.

o ApoA, a protein component of HDL that allows it to remove excess cholesterol from the bloodstream, was higher among HRT users in both groups of women compared to never users.

o ApoB, associated with vessel blockage, was lower among HRT users in both groups of women compared to never users.

o GHb, or glycosylated hemoglobin, an indicator of poor glycemic control, was lower among diabetic women using HRT compared to previous and never users.

Additional researchers involved in the study were Christopher T. Sempos, Ph.D., and Ellen Smit, Ph.D., from the UB Department of Social and Preventive Medicine; Anastacia Snelling, Ph.D., from American University, and Ross E. Anderson, Ph.D., from The Johns Hopkins University.

The research was supported by the National Institute on Aging and Wyeth-Ayerst Laboratories.