Abdominal adiposity and hot flashes among midlife women

Abstract

Objective-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. Design-TheStudy of Women's Health Across the Nation Heart Study (2001)(2002)(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 globulinadjusted estradiol (free estradiol index). Associations were evaluated within multivariable logistic and linear regression models.Results-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.Conclusion-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.Address correspondence to: Rebecca C. Thurston, PhD, University of Pittsburgh, 3811 O'Hara Street; Pittsburgh, PA 15217. thurstonrc@upmc.edu. Financial disclosure: None reported. NIH Public Access Author ManuscriptMenopause. Author manuscript; available in PMC 2010 May 25. It has been proposed that body size and composition can influence the risk of hot flashes. The "thin hypothesis" 9,10 asserts that women with more adipose tissue would have higher circulating estrogen and thus would have a lower risk of hot flashes. Hot flashes are believed to be due in part to declining estrogen levels. With diminished cyclic estradiol (E 2 ) secretion from the ovary during the menopausal transition, 2 adipose tissue may provide a supplemental source of estrogen due to aromatization of androstenedione to estrone (E 1 ) and limited conversion of E 1 to E 2 via 17β-hydroxysteroid dehydrogenase. Thus, according to the thin hypothesis, women with more adipose tissue would have a lower risk of hot flashes.Recent findings showing increased hot flashes among women with higher body mass index (BMI) have called the thin hypothesis into question. 1,11,12 These findings are consistent with thermoregulatory models of hot flashes, emphasizing the altered thermoregulatory func...

Perceived control, lifestyle, health, socio-demographic factors and menopause: Impact on hot flashes and night sweats

“…Although intake of alcohol [3,11,12,14,16] and hot beverages [12], physical exercise [1,10,11,14,15], body mass index (BMI) [4,12,14,[18][19][20] and smoking [1,3,8,12,17] have been considered predictors of vasomotor symptoms, the vast majority of lifestyle factors in the present study had no causal associations with the perceived severity of these symptoms.…”

“…For instance, alcohol [3,11,12,14,16], smoking [1,3,8,12,17], physical exercise [1,10,11,14,15], body mass index (BMI) [4,12,14,[18][19][20] and educational level [3] have all been reported to predict either an increase or a significant decrease in the reporting of vasomotor symptoms. Some factors may have an impact on both (HF and NS) or on only one symptom.…”

Reported Symptoms Before and One Year After Hysterectomy in African American and White Women

“…Multivariable analyses that controlled for these variables did not alter the major conclusions that there were significant differences in symptoms between women undergoing hysterectomy and control women at baseline but not at the 1-year follow-up. Furthermore, given that higher BMI and lower educational level have been reported to be associated with higher symptom levels, 28,29 the fact that the women with hysterectomies did not have higher symptom scores than the control women despite having a higher BMI and lower educational level further strengthens the conclusions that after surgery, women with hysterectomies have a symptom profile that is no worse than that of women in the general population.…”

Factors That May Influence the Experience of Hot Flushes by Healthy Middle-Aged Women

“…63,64 The latter model is questioned by the findings of a case-control study by Gallicchio et al 65 and a cross-sectional study by Schilling et al, 66 who found significantly lower levels of estrogen in obese women (BMI 35 kg=m 2 , BMI >30 kg=m 2 , respectively) compared with normal-weight midlife women (BMI <25 kg=m 2 ). Similarly, other studies indicate that higher BMI 10,52,54,65,67,68 and a higher percentage of body fat 63,69 are associated with increased odds of reporting VMS. Although there is greater evidence in support of the thermoregulatory model than the thin hypothesis, it cannot solely explain the pathogenesis of HFs.…”