1. ^*Laboratory of Biosystems and Cancer, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
2. ^†Cancer Prevention Fellowship Program, Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland
3. ^‡Center for Human Nutrition, University of California-Los Angeles School of Medicine, Los Angeles, California
4. ^§Applied Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland
5. ^¶Department of Preventive Medicine, University of Southern California, Alhambra, California

Correspondence: Stephen D. Hursting Division of Nutritional Sciences, University of Texas at Austin, One University Station, A2700, Austin, TX 78712. E-mail: shursting@mail.utexas.edu

^*The costs of publication of this article were defrayed, in part, by the payment of page charges. This article must, therefore, be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Received 5 January 2006; Revised  0000; Accepted 18 January 2007.

Abstract

Objective: To evaluate the effects of body adiposity on bone mineral density in the presence and absence of ovarian hormones in female mice and postmenopausal women.

Research Methods and Procedures: We assessed percentage body fat, serum leptin levels, and bone mineral density in ovariectomized and non-ovariectomized C57BL/6 female mice that had been fed various calorically dense diets to induce body weight profiles ranging from lean to very obese. Additionally, we assessed percentage body fat and whole body bone mineral density in 37 overweight and extremely obese postmenopausal women from the Women's Contraceptive and Reproductive Experiences study.

Results: In mice, higher levels of body adiposity (>40% body fat) were associated with lower bone mineral density in ovariectomized C57BL/6 female mice. A similar trend was observed in a small sample of postmenopausal women.

Discussion: The complementary studies in mice and women suggest that extreme obesity in postmenopausal women may be associated with reduced bone mineral density. Thus, extreme obesity (BMI > 40 kg/m²) may increase the risk for osteopenia and osteoporosis. Given the obesity epidemic in the U.S. and in many other countries, and, in particular, the rising number of extremely obese adult women, increased attention should be drawn to the significant and interrelated public health issues of obesity and osteoporosis.