Relationships among body composition measures in community-dwelling older women

Association of adiposity evaluated by anthropometric, BIA, and DXA measures with cardiometabolic risk factors in nonobese postmenopausal women: the CoLaus/OsteoLaus cohort

OBJECTIVE

After menopause, body composition changes with body fat accumulation, and an increase in cardiometabolic risk factors. Total fat mass, regional fat mass, and visceral adipose tissue (VAT) may be estimated with anthropometric measures, bioelectrical impedance analysis (BIA), and dual-energy X-ray absorptiometry (DXA). The aim of our study was to assess which measurement correlated best with cardiometabolic risk factors in healthy nonobese postmenopausal women.

METHODS

The CoLaus/OsteoLaus cohort included 1,500 postmenopausal women (age range 50-80). We analyzed correlations between: 1) measurements of body composition assessed by anthropometric measures, BIA, and DXA and 2) these measurements and different selected cardiometabolic risk factors, such as blood pressure, lipid markers (cholesterol subtypes and triglycerides), and metabolic markers (glucose, insulin, adiponectin, and leptin). Spearman correlation coefficient, stepwise forward regression, and linear regression analyses were used to determine association between anthropometric measurements and cardiometabolic risk factors.

RESULTS

In the 803 included participants (mean age 62.0 ± 7.1 y, mean body mass index 25.6 kg/m2 ± 4.4), correlations between total fat mass measured by BIA and total fat mass, android fat, gynoid fat, or VAT measured by DXA are very strong (from r = 0.531, [99% confidence interval (CI), 0.443-0.610] to r = 0.704, [99% CI, 0.640-0.758]). Body mass index and waist circumference have a higher correlation with VAT (r = 0.815, [99% CI, 0.772-0.851] and r = 0.823 [99% CI, 0.782-0.858], respectively) than BIA (r = 0.672 [99% CI, 0.603-0.731]). Among the anthropometric measurement and the measurements derived from DXA and BIA, VAT is the parameter most strongly associated with cardiometabolic risk factors. VAT better explains the variation of most of the cardiometabolic risk factors than age and treatment. For example, nearly 5% of the variability of the diastolic blood pressure (9.9 vs 4.9), nearly 15% of the variability of high-density lipoprotein cholesterol (20.3 vs 3.8) and triglyceride (21.1 vs 6.5), 25.3% of the variability of insulin (33.3 vs 8.1), and 37.5% of the variability of leptin (37.7 vs 1.1) were explained by VAT.

CONCLUSIONS

BIA seems not to be a good tool to assess VAT. At the population level, waist circumference and body mass index seem to be good tools to estimate VAT. VAT measured by DXA is the parameter most correlated with cardiometabolic risk factors and could become a component of the cardiometabolic marker on its own.

Stronger Associations of Body Mass Index and Waist Circumference with Diabetes than Waist-Height Ratio and Triglyceride Glucose Index in the Middle-Aged and Elderly Population: A Retrospective Cohort Study

BACKGROUND

It remains controversial whether body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), or triglyceride glucose (TyG) index has a stronger association with diabetes. The aims of the study were to compare the magnitude of associations of four indicators with diabetes risk.

METHODS

Data collected from annual health examination dataset in the Xinzheng during 2011 and 2019. A total of 41,242 participants aged ≥ 45 years were included in this study. Cox proportional hazard regression models were used to examine associations between the four indicators and diabetes risk.

RESULTS

After 205,770 person-years of follow up, diabetes developed in 2,472 subjects. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of diabetes (highest vs reference group) were 1.92 (1.71-2.16) for BMI, 1.99 (1.78-2.23) for WC, 1.65 (1.47-1.86) for WHtR, and 1.66 (1.47-1.87) for TyG, respectively. In addition, the risk of diabetes increased with baseline BMI (HR: 1.30; 95% CI: 1.25, 1.35) and TyG (HR: 1.25; 95% CI: 1.20, 1.30), but the lowest HR was 0.78 (95% CI 0.65-0.92) when WC was approximately 72 cm, and 0.85 (95% CI 0.72-0.99) when WHtR was approximately 0.47 in women. In joint analyses, the highest risk was observed in participants with a high BMI combined with a high WC (HR: 2.26; 95% CI: 1.98, 2.58).

CONCLUSIONS

In middle-aged and elderly Chinese population, BMI and WC were more strongly associated with diabetes than WHtR or TyG, especially the combined effect of BMI and WC.

DXA-Based Measurements in Diabetes: Can They Predict Fracture Risk?

In the absence of a fragility fracture, osteoporosis is usually diagnosed from bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA). Osteoporosis is an increasingly prevalent disease, as is diabetes [in particular type 2 diabetes (T2D)], in part due to aging populations worldwide. It has been suggested that an increased risk of fracture may be another complication ensuing from longstanding diabetes. The purpose of this review is to concentrate on skeletal parameters and techniques readily available from DXA scanning, and their utility in routine clinical practice for predicting fracture risk. In addition to BMD, other applications and measures from DXA include trabecular bone score (TBS), skeletal geometry and DXA-based finite-element analysis, vertebral fracture assessment, and body composition. In type 1 diabetes (T1D), BMD and FRAX^R (when secondary osteoporosis is included without BMD) only partially account for the excess risk of fracture in T1D. Consistent data exist to show that BMD and FRAX^R can be used to stratify fracture risk in T2D, but do not account for the increased risk of fracture. However, several adjustments to the FRAX score can be made as proxies for T2D to inform the use of FRAX by primary care practitioners. Examples include using the rheumatoid arthritis input (as a proxy for T2D), lumbar spine TBS (to adjust FRAX probability) or an altered hip T-score (lowered by 0.5 units). These adjustments can improve fracture risk prediction in T2D and help to avoid systematically underestimating the risk of osteoporosis-related fractures in those with diabetes.

BMI and all-cause mortality among middle-aged and older adults in Taiwan: a population-based cohort study

OBJECTIVE

The present study investigates the relationship between BMI and all-cause mortality among middle-aged and older adults with or without pre-existing diseases.

DESIGN

A population-based cohort study.

SETTING

The Taiwan Longitudinal Study on Aging is a nationwide prospective cohort study comprising a representative random sample of middle-aged and older adults. The study period was 1996-2007.

SUBJECTS

We followed 4145 middle-aged and older adults, totalling 42,353 person-years.

RESULTS

Overweight and mildly obese participants showed a 16% and 30% decrease in the risk of death, respectively, compared with those of normal weight after adjusting for potential covariates (e.g. demographic characteristics, health behaviour, co-morbidities and physical function). Underweight adults showed a 1.36-fold increased adjusted hazard ratio of death compared with normal-weight adults. Adults with a BMI of 27.0-28.0 kg/m(2) showed a significantly lower adjusted hazard ratio of all-cause mortality rate compared with adults who had normal BMI values when they had coexisting hypertension or diabetes (adjusted hazard ratio = 0.50; 95% CI 0.30, 0.81 for hypertension and adjusted hazard ratio=0.41; 95% CI 0.18, 0.89 for diabetes).

CONCLUSIONS

The study demonstrates that underweight people have a higher risk of death, and overweight and mildly obese people have a lower risk of death, compared with people of normal weight among middle-aged and older adults. An optimal BMI may be based on the individual, who exhibits pre-existing diseases or not.

Overweight and class I obesity are associated with lower 10-year risk of mortality in Brazilian older adults: the Bambuí Cohort Study of Ageing

Background

Prospective studies mostly with European and North-American populations have shown inconsistent results regarding the association of overweight/obesity and mortality in older adults. Our aim was to investigate the relationship between overweight/ obesity and mortality in an elderly Brazilian population.

Methods and Findings

Participants were 1,450 (90.2% from total) individuals aged 60 years and over from the community-based Bambuí (Brazil) Cohort Study of Ageing. From 1997 to 2007, 521 participants died and 89 were lost, leading to 12,905 person-years of observation. Body mass index (BMI) and waist circumference (WC) were assessed at baseline and at the 3rd and 5th years of follow-up. Multiple imputation was performed to deal with missing values. Hazard ratios (HR) of mortality for BMI or WC alone (continuous and categorical), and BMI and WC together (continuous) were estimated by extended Cox regression models, which were fitted for clinical, socioeconomic and behavioral confounders. Adjusted absolute rates of death at 10-year follow-up were estimated for the participants with complete data at baseline. Continuous BMI (HR 0.85; 95% CI 0.80–0.90) was inversely related to mortality, even after exclusion of smokers (HR 0.85; 0.80–0.90), and participants who had weight variation and died within the first 5 years of follow-up (HR 0.83; CI 95% 0.73–0.94). Overweight (BMI 25–30 kg/m²) was inversely (HR 0.76; 95%CI 0.61–0.93) and obesity (BMI ≥30 kg/m²; HR 0.85; 95% CI 0.64–1.14) not significantly associated with mortality. Subjects with BMI between 25–35 kg/m² (23.8–25.9%) had the lowest absolute rates of death at 10-years follow-up. The association between WC and death was not significant, except after adjusting WC for BMI levels, when the relationship turned into marginally positive (HR 1.01; CI 95% 1.00–1.02).

Conclusions

The usual BMI and WC cut-off points should not be used to guide public health and clinical weight control interventions in elderly in Brazil.

Lifestyle modification increases circulating adiponectin concentrations but does not change vaspin concentrations

The objective of the study was to evaluate the effects of a 10-month lifestyle intervention on the components of the metabolic syndrome (MetSyn) in Koreans with MetSyn as well as on blood concentrations of adiponectin and vaspin. One hundred thirty-eight patients with MetSyn, recruited from a community health care center, were consecutively enrolled in the study; 12 patients dropped of the intervention, leaving 126 subjects (76 men and 50 women; age, 65.3 ± 9.0 years). All participants followed a 10-month lifestyle modification interventional program, including dietary counseling, advice on increasing physical activity, and recommendations to stop or limit smoking and alcohol drinking. Anthropometric and biochemical parameters related to the components of the MetSyn, including blood concentrations of adiponectin and vaspin, were assessed pre- and postintervention. At baseline, adiponectin concentrations were moderately negatively correlated to insulin concentrations and insulin resistance evaluated by the homeostasis model assessment. In response to lifestyle modification, statistically significant changes were found in systolic and diastolic blood pressure, total cholesterol, triglyceride, and insulin concentrations, as well as in homeostasis model assessment of insulin resistance. Adiponectin concentrations postintervention, compared with the preintervention levels, increased (7.2 ± 4.0 vs 6.8 ± 3.9 μg/mL, respectively; P < .05), whereas vaspin concentrations remained unchanged (0.25 ± 0.19 vs 0.26 ± 0.20 ng/mL, respectively; P = .64). A 10-month lifestyle modification program in Korean patients with MetSyn led to favorable changes in metabolic parameters and adiponectin but not vaspin concentrations.

Association of body mass index with self-report and performance-based measures of balance and mobility

BACKGROUND

The incidence of obesity is increasing in older adults, with associated worsening in the burden of disability. Little is known about the impact of body mass index (BMI) on self-report and performance-based balance and mobility measures in older adults.

OBJECTIVE

The purposes of this study were (1) to examine the association of BMI with measures of balance and mobility and (2) to explore potential explanatory factors.

DESIGN

This was a cross-sectional, observational study.

METHODS

Older adults (mean age=77.6 years) who participated in an ongoing observational study (N=120) were classified as normal weight (BMI=18.5-24.9 kg/m(2)), overweight (BMI=25.0-29.9 kg/m(2)), moderately obese (BMI=30.0-34.9 kg/m(2)), or severely obese (BMI ≥ 35 kg/m(2)). Body mass index data were missing for one individual; thus, data for 119 participants were included in the analysis. Mobility and balance were assessed using self-report and performance-based measures and were compared among weight groups using analysis of variance and chi-square analysis for categorical data. Multiple linear regression analysis was used to examine the association among BMI, mobility, and balance after controlling for potential confounding variables.

RESULTS

Compared with participants who were of normal weight or overweight, those with moderate or severe obesity were less likely to report their mobility as very good or excellent (52%, 55%, 39%, and 6%, respectively); however, there was no difference in self-report of balance among weight groups. Participants with severe obesity (n=17) had the lowest levels of mobility on the performance-based measures, followed by those who were moderately obese (n=31), overweight (n=42), and of normal weight (n=29). There were no differences on performance-based balance measures among weight groups. After controlling for age, sex, minority status, physical activity level, education level, and comorbid conditions, BMI still significantly contributed to mobility (β=-.02, adjusted R(2)=.41).

CONCLUSIONS

Although older adults with severe obesity were most impaired, those with less severe obesity also demonstrated significant decrements in mobility.

Appendicitis, Body Mass Index, and CT: Is CT More Valuable for Obese Patients than Thin Patients?

The purpose of our study is to determine whether body mass index (BMI = weight in kg/height in meters2) was related to the rate of negative appendectomy in patients who underwent preoperative CT. A surgical database search performed using the procedure code for appendectomy identified 925 patients at least 18 years of age who underwent urgent appendectomy between January 1998 and September 2007. BMI was computed for the 703 of these 925 patients for whom height and weight information was available. Patients were stratified based on body mass index (BMI 15-18.49 = underweight; 18.5-24.9 = normal weight; 25–29.9 = overweight; 30-39.9 = obese; > 40 = morbidly obese). Negative appendectomy rates were computed. Negative appendectomy rates for patients who did and did not undergo preoperative CT were 27 per cent and 50 per cent for underweight patients, 10 per cent and 15 per cent for normal weight patients, 12 per cent and 17 per cent for overweight patients, 7 per cent and 30 per cent for obese patients, and 10 per cent and 100 per cent for morbidly obese patients. The difference in negative appendectomy rates for overweight patients, obese patients, and morbidly obese patients who underwent preoperative CT as compared with patients in the same BMI category who did not undergo preoperative CT was statistically significant ( P ≤ 0.001). The negative appendectomy rates for overweight patients, obese patients, and morbidly obese patients who underwent preoperative CT were significantly lower than for patients in these same BMI categories who did not undergo preoperative CT.

MRI assessment of lean and adipose tissue distribution in female patients with Cushing's disease

OBJECTIVE

Chronic hypercortisolemia due to Cushing's disease (CD) results in abnormal adipose tissue (AT) distribution. Whole-body magnetic resonance imaging (MRI) was used to examine lean and AT distribution in female patients with CD to further understand the role of glucocorticoid excess in the development of abnormal AT distribution and obesity.

DESIGN

Cross-sectional and case-control study.

PATIENTS

Fifteen women with CD and 12 healthy controls.

MEASUREMENTS

Mass of skeletal muscle (SM) and AT in the visceral (VAT), subcutaneous (SAT), and intermuscular (IMAT) compartments from whole-body MRI and serum levels of insulin, glucose, and leptin were measured.

RESULTS

CD patients had leptin values that correlated to total AT (TAT) and SAT (P < 0.05) but not to VAT. CD patients had higher VAT/TAT ratios (P < 0.01) and lower SAT/TAT ratios (P < 0.05) compared to controls. TAT, VAT, and trunk SAT (TrSAT) were greater in CD patients (P < 0.01). SM was less in CD (P < 0.001) but IMAT was not different.

CONCLUSIONS

TAT, VAT, trSAT, and the proportion of AT in the visceral depot were greater in CD although the proportion in the subcutaneous depot was less. SM was less but IMAT was not different. These findings have implications for understanding the role of cortisol in the abnormal AT distribution and metabolic risk seen in patients exposed to chronic excess glucocorticoids.

Abdominal fat from spine dual-energy x-ray absorptiometry and risk for subsequent diabetes

CONTEXT

Abdominal obesity is a major risk factor for diabetes. Dual-energy x-ray absorptiometry (DXA) of the lumbar spine provides an index of abdominal fat.

OBJECTIVE

Our objective was to examine the hypothesis that DXA-derived abdominal fat measurement in women undergoing osteoporosis investigation predicts risk for subsequent diagnosis of diabetes.

DESIGN

This historical cohort study was derived from the Manitoba Bone Density Program Database for the Province of Manitoba, Canada.

SETTING AND PATIENTS

30,252 nondiabetic women aged 40 yr and older were referred for baseline osteoporosis assessment with DXA between January 1990 and March 2007.

MAIN OUTCOME MEASURES

Each woman's longitudinal provincial health service record was assessed for the presence of diabetes diagnosis codes after DXA testing.

RESULTS

During 5.2 + or - 2.6 yr of observation, 1252 (4.1%) women met the case definition for diabetes. A greater proportion of abdominal fat from spine DXA was strongly related to subsequent diabetes diagnosis in models adjusted for age, body mass index, and other comorbidities. Those in the highest quintile had 3.56 (95% confidence interval = 2.67-4.75) times the risk for subsequent diabetes diagnosis compared with those in the lowest (reference) quintile. Fat from hip DXA was not predictive of subsequent diabetes after adjustment for the same variables (1.00, 95% confidence interval = 0.79-1.26).

CONCLUSIONS

Predictive information about diabetes risk can be obtained from spine DXA scans performed for osteoporosis risk assessment. This is consistent with evidence linking abdominal fat with insulin resistance and the metabolic syndrome.

Association between adiposity in midlife and older age and risk of diabetes in older adults

CONTEXT

Adiposity is a well-recognized risk factor for type 2 diabetes among young and middle-aged adults, but the relationship between body composition and type 2 diabetes is not well described among older adults.

OBJECTIVE

To examine the relationship between adiposity, changes in adiposity, and risk of incident type 2 diabetes in adults 65 years of age and older.

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort study (1989-2007) of 4193 men and women 65 years of age and older in the Cardiovascular Health Study. Measures of adiposity were derived from anthropometry and bioelectrical impedance data at baseline and anthropometry repeated 3 years later.

MAIN OUTCOME MEASURE

Incident diabetes was ascertained based on use of antidiabetic medication or a fasting glucose level of 126 mg/dL or greater.

RESULTS

Over median follow-up of 12.4 years (range, 0.9-17.8 years), 339 cases of incident diabetes were ascertained (7.1/1000 person-years). The adjusted hazard ratio (HR) (95% confidence interval [CI]) of type 2 diabetes for participants in the highest quintile of baseline measures compared with those in the lowest was 4.3 (95% CI, 2.9-6.5) for body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]), 3.0 (95% CI, 2.0-4.3) for BMI at 50 years of age, 4.2 (95% CI, 2.8-6.4) for weight, 4.0 (95% CI, 2.6-6.0) for fat mass, 4.2 (95% CI, 2.8-6.2) for waist circumference, 2.4 (95% CI, 1.6-3.5) for waist-hip ratio, and 3.8 (95% CI, 2.6-5.5) for waist-height ratio. However, when stratified by age, participants 75 years of age and older had HRs approximately half as large as those 65 to 74 years of age. Compared with weight-stable participants (+/-2 kg), those who gained the most weight from 50 years of age to baseline (> or = 9 kg), and from baseline to the third follow-up visit (> or = 6 kg), had HRs for type 2 diabetes of 2.8 (95% CI, 1.9-4.3) and 2.0 (95% CI, 1.1-3.7), respectively. Participants with a greater than 10-cm increase in waist size from baseline to the third follow-up visit had an HR of type 2 diabetes of 1.7 (95% CI, 1.1-2.8) compared with those who gained or lost 2 cm or less.

CONCLUSION

Among older adults, overall and central adiposity, and weight gain during middle age and after the age of 65 years are associated with risk of diabetes.

Prediction of body composition from spine and hip bone densitometry

Body mass index (BMI) is used to assess overweight and obesity, but it does not account for the distribution or composition of excess weight. Dual-energy X-ray absorptiometry (DXA) is widely used for the assessment of osteoporosis. We hypothesized that measures of regional fat tissue composition from spine and hip DXA done for osteoporosis assessment could be used to estimate body composition more accurately than with BMI. We identified 427 adult patients who underwent DXA evaluation of the lumbar spine, hip, and whole body at the same visit. The population was randomly divided into 2 equal-sized subgroups: one used to derive prediction equations for whole-body fat tissue, whole-body lean tissue, and trunk fat tissue, and the other for independent validation. The estimates were compared with the actual measurements from the whole-body scans. In all analyses, prediction using the regional DXA scans outperformed prediction using BMI or its component variables, height and weight. When the predicted and actual measurements were compared in the validation cohort, regression slopes did not differ significantly from unity and the intercepts did not differ significantly from zero. We conclude that regional DXA scans of the spine and hip can be used to accurately measure body composition. Further research is needed to see whether these measures can in turn predict the metabolic complications associated with overweight and obesity.

Obesity and metabolic syndrome increase the risk of incident depression in older men: the health in men study

BACKGROUND

Obesity has been associated with increased risk of prevalent depression among young and middle-aged adults, but the association between obesity (and its various measures, including the metabolic syndrome [MetS]) and incident depression has not been examined adequately in the elderly.

OBJECTIVES

This study evaluated the association between various measures of obesity and incident depression over a 10-year period in a large cohort of community-based older men.

METHODS

The authors recruited 12,216 men aged 65-84 years living in Perth, Australia, between 1996 and 1998, and measured their height, weight, waist and hip circumference, and blood pressure. Participants also completed a questionnaire that included information about the clinical diagnosis and treatment for diabetes, hypertension, and high cholesterol or triglycerides. The authors then used the Western Australian Linked Data System to retrieve information about the following ICD-10 diagnoses between January 1, 1966, and December 31, 2006: depressive episode, recurrent depressive disorder, and dysthymia.

RESULTS

The authors excluded 150 men from these analyses because of prior history of depression or missing data. The mean age of our 12,066 participants was 72 +/- 4 years at the time of recruitment, and they were followed up for an average of 8 +/- 2 years. There were 3,623 deaths during follow-up, and 481 men received the diagnosis of depression. The incidence of depression was 5 per 1,000 person-years. Adjusted Cox proportional hazard models showed that men with body mass index (BMI) > or =30 had a 31% (95% confidence interval [CI] = 5%-64%) increase in the risk of depression compared with that of nonobese men (BMI <30). The association between depression and waist circumference > or =102 cm and waist/hip > or =1 did not reach statistical significance. Men with MetS at the time of recruitment had a 137% (95% CI = 60%-251%) increase in the adjusted risk of incident depression.

CONCLUSIONS

Our results indicate that obesity and MetS are associated with an increase in the risk of incident depression among older men. If this association is truly causal, reducing the prevalence of obesity and MetS could potentially lead to a decline in the prevalence and incidence of depression in later life.

Sagittal abdominal diameter is more predictive of cardiovascular risk than abdominal fat compartments in severe obesity

OBJECTIVE

To compare the predictive role of abdominal fat distribution by computed tomography (CT) with that of total abdominal fat by sagittal abdominal diameter (SAD) on cardiovascular risk in severe obesity.

DESIGN

A cross-sectional, clinical study.

SUBJECTS

64 males and 64 females, aged 42+/-15 years (mean+/-s.d.; range 18-75 years), BMI (kg/m(2)) 41.7+/-5.3 (30.2-57.6).

MEASUREMENTS

Blood glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides (TGLs), insulin (IRI), insulin resistance (HOMA-IR), slice areas (cm(2)) of total (tSAT), superficial (sSAT) and deep subcutaneous adipose tissue (dSAT), visceral adipose tissue (VAT) and SAD (mm) by CT.

RESULTS

The sSAT depot was negatively associated with blood glucose, HOMA-IR, LDL cholesterol and TGLs, whereas dSAT was negatively associated with HDL cholesterol. VAT was associated with blood glucose and HOMA-IR, whereas SAD was associated with all variables evaluated. In males, VAT was associated with blood glucose (r(2)=0.12, P<0.01), SAD was associated with blood glucose (r(2)=0.67, P<0.01), IRI (r(2)=0.65, P<0.05), and HOMA-IR (r(2)=0.67, P<0.01). In females, sSAT was negatively associated with blood glucose (r(2)=0.63, P<0.05), whereas VAT was associated positively with blood glucose (r(2)=0.21, P< 0.001), total cholesterol (r(2)=0.16, P<0.01), LDL cholesterol (r(2)=0.20, P<0.001) and TGLs (r(2)=0.12, P<0.01). SAD was associated positively with IRI (r(2)=0.52, P<0.05), HOMA-IR (r(2)=0.53, P<0.05), total cholesterol (r(2)=0.52, P<0.05), LDL cholesterol (r(2)=0.54, P<0.01), TGLs (r(2)=0.52, P<0.05) and negatively to HDL cholesterol (r(2)=0.51, P<0.001).

CONCLUSION

When compared with CT-based measures of abdominal fat compartments, SAD is a more predictive indicator of cardiovascular risk in severe obesity.

Abdominal adiposity and hot flashes among midlife women

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

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.

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.