News Briefs from the Endocrine Society

1. Weight Maintenance May Be Linked to Decreased Bone Density in Menopausal Women
2. Metals in Tobacco Smoke May Increase Risk of Breast Cancer
3. New Patient Guide on the Management of Maternal Hypothyroidism Before, During and After Pregnancy Now Available from The Hormone Foundation

1. Weight Maintenance May Be Linked to Decreased Bone Density in Menopausal Women

Newswise — Women going through menopause gain an average of one pound of body weight each year. New research reveals, however, that efforts to minimize or reverse this trend have the undesirable side effect of decreasing bone mineral density (BMD), putting those who are most successful at controlling weight gain at greater risk of osteoporosis.

“Weight reduction is often encouraged in overweight perimenopausal women and weight maintenance is recommended in normal weight perimenopausal women,” said Dr. Jane A. Cauley of the University of Pittsburgh’s Graduate School of Public Health and co-author of the study. “However, our research reveals that lifestyle interventions to control weight gain can have negative consequences for a woman’s bone mineral density.”

The results were discovered during the Women’s Healthy Lifestyle Project, a 5-year study of 535 premenopausal women in Allegheny County, Pennsylvania. The project goal was to determine if lifestyle interventions could control cholesterol and weight gain during menopause. The lifestyle interventions focused on a low-fat diet and exercise.

The interventions were successful in preventing weight gain and its associated increases in LDL cholesterol; women in the intervention group gained an average of 2.8 kilograms (6.2 pounds) less than women in the control group. However, during the intervention, women in the intervention group also experienced greater loss in BMD, especially at the total hip and femoral neck.

It was also noted in this study that women taking hormone replacement therapy had slightly less, but still statistically significant BMD loss. “This study suggests that the use of hormones many not totally protect women from weight loss associated bone loss,” said Cauley. Clinicians need to consider the potential loss of BMD when providing lifestyle and weight loss recommendations to midlife women, according to Cauley.

It is estimated that each year women normally lose 1.15 percent of spine bone BMD and 0.85 percent of femur neck BMD in the immediate postmenopausal period, tapering off to 0.20 percent and 0.57 percent, respectively.

A rapid release version of this paper has been published on-line and will appear in the October 2007 issue of the Journal of Clinical Endocrinology & Metabolism, a publication of The Endocrine Society.

Title
Effects of Weight Control During the Menopausal Transition on Bone Mineral Density
Authors
Hyun A. Park, Jung S. Lee, Lewis H. Kuller, and Jane A. Cauley

2. Metals in Tobacco Smoke May Increase Risk of Breast Cancer

Researchers have found that metals present in tobacco smoke mimic the effects of estrogens and activate the body’s estrogen receptor, an action that may increase the risk of breast cancer. These metals are a new class of potent environmental estrogens called metalloestrogens, and smoking is a significant route of exposure.

“The ability of tobacco smoke to mimic the effects of estrogens suggests that the contaminants contribute to the etiology of breast cancer,” said Dr. Mary Beth Martin of Georgetown University and principal author of the study. “However, additional studies are required to clarify the association between cigarette smoking, metalloestrogens, and the disease.”

In the study human breast cancer cells were treated with tobacco smoke condensate (TSC). TSC was found to stimulate breast cancer cell growth, activate the estrogen receptor, and increase the expression of the estrogen regulated genes.

The mammary gland is unique in that it grows and develops throughout the lifetime of a female and estrogens play a central role in the growth and development of the gland. Early life exposure to environmental estrogens such as metalloestrogens may alter mammary gland development and, consequently, breast cancer risk.

This paper has been published online and will appear in the October 2007 issue of Endocrinology, a publication of The Endocrine Society.

Title
Effects of Tobacco Smoke Condensate on Estrogen Receptor-α Gene Expression and Activity

Authors
Mary B. Martin, Ronald Reiter, Michael Johnson, Mansi S. Shah, Mary C. Iann, Baljit Singh, Julie K. Richards, Antai Wang, and Adriana Stoica

3. New Patient Guide on the Management of Maternal Hypothyroidism Before, During and After Pregnancy Now Available from The Hormone Foundation

In conjunction with The Endocrine Society, The Hormone Foundation has published the "Patient Guide to the Management of Maternal Hypothyroidism Before, During and After Pregnancy." based on the clinical guidelines of The Endocrine Society. This publication is the first of three parts focusing on thyroid disease in pregnancy women. It summarizes who is at risk, the different causes for hypothyroidism, and special considerations for the management of hypothyroidism during and after pregnancy. The guide will be published in the August issue of The Journal of Clinical Endocrinology & Metabolism and the September issue of Endocrine News. (Part 2 of the patient guide will address maternal hyperthyroidism and part will address thyroid nodules and thyroid cancer during pregnancy.)

To view the patient guide on maternal hypothyroidism visit http://www.hormone.org/pdf/hypothyroid_women.pdf