Two competing hypotheses suggest how adiposity may affect menopausal hot flashes. The "thin hypothesis" asserts that aromatization of androgens to estrogens in body fat should be associated with decreased hot flashes. Conversely, thermoregulatory models argue that body fat should be associated with increased hot flashes. The study objective was to examine associations between abdominal adiposity and hot flashes, including the role of reproductive hormones in these associations.
The Study of Women's Health Across the Nation Heart Study (2001-2003) is an ancillary study to the Study of Women's Health Across the Nation, a community-based cohort study. Participants were 461 women (35% African American, 65% white) ages 45 to 58 years with an intact uterus and at least one ovary. Measures included a computed tomography scan to assess abdominal adiposity; reported hot flashes over the previous 2 weeks; and a blood sample for measurement of follicle-stimulating hormone, estradiol, and sex hormone-binding globulin-adjusted estradiol (free estradiol index). Associations were evaluated within multivariable logistic and linear regression models.
Every 1-SD increase in total (odds ratio [OR] = 1.28; 95% CI: 1.06-1.55) and subcutaneous (OR = 1.30; 95% CI: 1.07-1.58) abdominal adiposity was associated with increased odds of hot flashes in age- and site-adjusted models. Visceral adiposity was not associated with hot flashes. Associations were not reduced when models included reproductive hormone concentrations.
Increased abdominal adiposity, particularly subcutaneous adiposity, is associated with increased odds of hot flashes, favoring thermoregulatory models of hot flashes. Body fat may not protect women from hot flashes as once thought.
In the Study of Women's Health Across the Nation Heart Study, increased abdominal adiposity, particularly subcutaneous adiposity, was associated with increased odds of hot flashes, favoring thermoregulatory models of hot flashes. Body fat may not protect women from hot flashes as once thought.
From the 1Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA; 2Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI; 3Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA; 4Department of Preventive Medicine, Rush University Medical Center, Chicago, IL; 5Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT; and 6Cardiovascular Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA.
Received June 6, 2007; revised and accepted August 15, 2007.
Funding/support: The Study of Women's Health Across the Nation (SWAN) has grant support from the National Institutes of Health, Department of Health and Human Services, through the National Institute on Aging, the National Institute of Nursing Research and the NIH Office of Research on Women's Health (grants AG012505, AG012546). SWAN Heart was supported by grants from the National Institutes of Health, National Heart Lung and Blood Institute (grants HL065581, HL065591).
Financial disclosure: None reported.
Address correspondence to: Rebecca C. Thurston, PhD, University of Pittsburgh, 3811 O'Hara Street; Pittsburgh, PA 15217. E-mail: email@example.com