Is body mass index a measure of adiposity in elderly women?

Obesity among postmenopausal women: what is the best anthropometric index to assess adiposity and success of weight-loss intervention?

OBJECTIVES

First, to establish the respective ability of body mass index (BMI), waist circumference (WC), and relative fat mass index (RFM), to estimate body fat (BF%) measured by DXA (DXA-BF%) and correctly identify postmenopausal women living with obesity (BF% > 35). Second, to identify the best indicator of successful weight-loss intervention in postmenopausal women living with obesity.

METHODS

A total of 277 women (age: 59.8 ± 5.3 y; BF%: 43.4 ± 5.3) from five weight-loss studies with complete data for anthropometric measurements [BMI = weight/height (kg/m2); WC (cm)] and BF% were pooled together. Statistical performance indicators were determined to assess ability of RFM [64-(20 × height/waist circumference) + (12 × sex)], BMI and WC to estimate BF% before and after weight-loss intervention and to correctly identify postmenopausal women living with obesity.

RESULTS

Compared with RFM (r = 0.51; r2 = 0.27; RMSE = 4.4%; Lin's CCC = 0.46) and WC (r = 0.49; r2 = 0.25; RMSE = 4.8%; Lin's CCC = 0.41), BMI (r = 0.73; r2 = 0.52; RMSE = 3.7%; Lin's CCC = 0.71) was the best anthropometric index to estimate DXA-BF% and correctly identify postmenopausal women living with obesity (sensitivity + specificity: BMI = 193; RFM = 152; WC = 158), with lower misclassification error, before weight-loss intervention. After weight-loss, the change in BMI was strongly correlated with change in DXA-BF%, indicating that the BMI is the best indicator of success weight-loss intervention.

CONCLUSION

In the absence of more objective measures of adiposity, BMI is a suitable proxy measure for BF% in postmenopausal women, for whom a lifestyle intervention is relevant. Furthermore, BMI can be used as an indicator to assess success of weight-loss intervention in this subpopulation.

Repository Describing an Aging Population to Inform Physiologically Based Pharmacokinetic Models Considering Anatomical, Physiological, and Biological Age-Dependent Changes

BACKGROUND

Aging is characterized by anatomical, physiological, and biological changes that can impact drug kinetics. The elderly are often excluded from clinical trials and knowledge about drug kinetics and drug-drug interaction magnitudes is sparse. Physiologically based pharmacokinetic modeling can overcome this clinical limitation but detailed descriptions of the population characteristics are essential to adequately inform models.

OBJECTIVE

The objective of this study was to develop and verify a population database for aging Caucasians considering anatomical, physiological, and biological system parameters required to inform a physiologically based pharmacokinetic model that included population variability.

METHODS

A structured literature search was performed to analyze age-dependent changes of system parameters. All collated data were carefully analyzed, and descriptive mathematical equations were derived.

RESULTS

A total of 362 studies were found of which 318 studies were included in the analysis as they reported rich data for anthropometric parameters and specific organs (e.g., liver). Continuous functions could be derived for most system parameters describing a Caucasian population from 20 to 99 years of age with variability. Areas with sparse data were identified such as tissue composition, but knowledge gaps were filled with plausible qualified assumptions. The developed population was implemented in Matlab^® and estimated system parameters from 1000 virtual individuals were in accordance with independent observed data showing the robustness of the developed population.

CONCLUSIONS

The developed repository for aging subjects provides a singular specific source for key system parameters needed for physiologically based pharmacokinetic modeling and can in turn be used to investigate drug kinetics and drug-drug interaction magnitudes in the elderly.

Anthropometric patterns of adiposity, hypertension and diabetes mellitus in older adults of Viçosa, Brazil: A population-based study

AIM

To identify anthropometric patterns of adiposity and estimate their association with hypertension and diabetes mellitus (DM) in older adults.

METHODS

A cross-sectional study with 537 older adults aged ≥60 years was carried out. Weight, height, and waist, hip and calf circumference were measured. The following indices were calculated: a body shape index, body roundness index, conicity index, body adiposity index, body mass index, waist-to-height ratio, waist-to-calf ratio, waist-to-hip ratio and waist-to-hip-to-height ratio. The anthropometric patterns of adiposity were obtained by factor analysis of principal components, and their association with hypertension and DM was identified by multiple Poisson regression with robust variance.

RESULTS

Two anthropometric patterns of adiposity were identified. Pattern 1 and 2 explained approximately 53% and 33% of the total variance, respectively, in both sexes. Pattern 1 indicated of global adiposity, and weight, body mass index and hip circumference were the variables most strongly correlated with this pattern in both sexes. Pattern 2 represented the body fat distribution, being a body shape index the most important variable in this factor. After adjustment by confounding factors, only the pattern 2 remained significantly associated with DM in women.

CONCLUSIONS

Only the anthropometric pattern of adiposity central was associated with DM in older women. Geriatr Gerontol Int 2018; 18: 584-591.

Waist-to-height ratio and sedentary lifestyle as predictors of metabolic syndrome in children in Ecuador

OBJECTIVE

To determine the predictors and prevalence of metabolic syndrome (MS) and the presence of vascular inflammation in apparently-normal children (10-15 years) of both sexes in Guayaquil, Ecuador.

STUDY DESIGN AND METHODS

We included 395 apparently-healthy students from a middle-income school in a cross-sectional survey. Informed consent was obtained from students and parents. Anthropometric measurements including blood pressure (BP), body mass index (BMI) and waist-to-height ratio (WHtR), and blood tests were recorded. Vascular inflammation parameters were assessed. Percentiles of the different parameters were used, and MS was defined according to National Cholesterol Education Program Adult Treatment Panel III criteria (NCEP-ATPIII). Waist circumference>P 75, blood pressure>P 90, glucose>100mg/dl, triglycerides>100mg/dl, HDL<45mg/dl. If 3 of the 5 criteria were present, this was considered MS.

RESULTS

The mean age was 12 years (186 boys, 209 girls). The overall prevalence of MS was 9.37% (6.33% in girls, 3.04% in boys). Sustained hypertension was detected in 6.6% of children and pre-hypertension in 7.1%. Obesity was found in 1.8% of subjects, and overweight in 15.2%. Triglycerides has a RR 2.34 (1.97-2.76); HOMA index has a RR 1.97(1.62-2.40); HDL cholesterol has a RR 1.84(1.58-2.13); Insulin level has a RR 1.53(1.40-1.67) and interleukin 6 has RR 1.83(1.20-2.79). Serum glucose, total cholesterol and LDL-Cholesterol had no association with the metabolic syndrome. HDL-Cholesterol<45mg/dl and triglyceride>100mg/dl were present in 70% of subjects with MS. The WHtR threshold≥0.5 was 100% sensitive in both sexes (67% specificity in boys and 69% in girls). There were significant associations between the WHtR and pre-hypertension and sedentary lifestyle (P<0.001 and P<0.003 respectively). A WHtR value of ≥0.50 indicated a 2.2-fold increased risk of MS compared with normal WHtR, and normal weight.

CONCLUSIONS

A WHtR≥0.5 was 100% sensitive in detecting MS in 10-15 year-old boys and girls in the normal or overweight range of the BMI. This assessment is a simple and practical tool for use in population-based studies of cardiovascular risk. When combined with pre-hypertension and a sedentary lifestyle, the WHtR is highly sensitive in predicting MS.

Relationships between cognitive function and body composition among community-dwelling older adults: a cross-sectional study

Background

Previous studies reported mixed results regarding the association between cognition and body weight in late life. We evaluated the relationships between cognitive function and body composition among community-dwelling older adults.

Methods

Three hundred twenty subjects (≥65 years, women 53%) with available data of cognitive function and body composition from 2010 Hallym Aging Study. Cognitive function was assessed using Korean Mini-Mental State Examination (K-MMSE). Dual-energy X-ray absorptiometry (DEXA) was used for measuring body composition including body fat and lean body mass. Anthropometric measurements and laboratory data were collected in clinical examination. Body composition variables were divided into sex-specific tertiles, and examined by multivariable logistic regression.

Results

Among female, the highest tertile group of fat mass and second tertile group of total lean body mass were associated with lower risk for cognitive impairment compared to the respective first tertile groups (odds ratios, 0.23 and 0.09, respectively; 95% confidence intervals, 0.04–0.88 and 0.01–0.44, respectively) after adjusting for confounding factors. In male, higher arm bone mineral content was associated with lower risk for cognitive impairment, but significance was lost after adjusting for adiponectin, age, and education.

Conclusions

Higher fat mass and lean body mass were associated with lower risk of cognitive impairment in older women. These observations suggest that body fat and lean mass later in life might be beneficial for cognition.

Electronic supplementary material

The online version of this article (10.1186/s12877-017-0651-9) contains supplementary material, which is available to authorized users.

Development of a Whole-Body Physiologically Based Pharmacokinetic Approach to Assess the Pharmacokinetics of Drugs in Elderly Individuals

Background

Because of the vulnerability and frailty of elderly adults, clinical drug development has traditionally been biased towards young and middle-aged adults. Recent efforts have begun to incorporate data from paediatric investigations. Nevertheless, the elderly often remain underrepresented in clinical trials, even though persons aged 65 years and older receive the majority of drug prescriptions. Consequently, a knowledge gap exists with regard to pharmacokinetic (PK) and pharmacodynamic (PD) responses in elderly subjects, leaving the safety and efficacy of medicines for this population unclear.

Objectives

The goal of this study was to extend a physiologically based pharmacokinetic (PBPK) model for adults to encompass the full course of healthy aging through to the age of 100 years, to support dose selection and improve pharmacotherapy for the elderly age group.

Methods

For parameterization of the PBPK model for healthy aging individuals, the literature was scanned for anthropometric and physiological data, which were consolidated and incorporated into the PBPK software PK-Sim^®. Age-related changes that occur from 65 to 100 years of age were the main focus of this work. For a sound and continuous description of an aging human, data on anatomical and physiological changes ranging from early adulthood to old age were included. The capability of the PBPK approach to predict distribution and elimination of drugs was verified using the test compounds morphine and furosemide, administered intravenously. Both are cleared by a single elimination pathway. PK parameters for the two compounds in younger adults and elderly individuals were obtained from the literature. Matching virtual populations—with regard to age, sex, anthropometric measures and dosage—were generated. Profiles of plasma drug concentrations over time, volume of distribution at steady state (V_ss) values and elimination half-life (t_½) values from the literature were compared with those predicted by PBPK simulations for both younger adults and the elderly.

Results

For most organs, the age-dependent information gathered in the extensive literature analysis was dense. In contrast, with respect to blood flow, the literature study produced only sparse data for several tissues, and in these cases, linear regression was required to capture the entire elderly age range. On the basis of age-informed physiology, the predicted PK profiles described age-associated trends well. The root mean squared prediction error for the prediction of plasma concentrations of furosemide and morphine in the elderly were improved by 32 and 49 %, respectively, by use of age-informed physiology. The majority of the individual V_ss and t_½ values for the two model compounds, furosemide and morphine, were well predicted in the elderly population, except for long furosemide half-lifes.

Conclusion

The results of this study support the feasibility of using a knowledge-driven PBPK aging model that includes the elderly to predict PK alterations throughout the entire course of aging, and thus to optimize drug therapy in elderly individuals. These results indicate that pharmacotherapy and safety-related control of geriatric drug therapy regimens may be greatly facilitated by the information gained from PBPK predictions.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-016-0422-3) contains supplementary material, which is available to authorized users.

Confiabilidade de indicadores antropométricos e fisiológicos para desenvolvimento de um índice de saúde para idosos

Objetivo Evaluar la fiabilidad de los indicadores antropométricos y fisiológicos para el desarrollo de un índice de salud para los ancianos.Métodos Estudio cuantitativo de corte transversal, con una muestra de 63 ancianos de ambos sexos, participantes del Proyecto Movimiento Cruz das Almas, como parte del Programa de Salud Familiar (PSF) de la ciudad de Cruz das Almas, Bahía. Con edades iguales o mayores de 60 años. Fueron 58 sujetos femeninos y cinco masculino. Se utilizaron procedimientos estadísticos multivariados de análisis de conglomerados y análisis de correlación de Spearman, para determinar la intensidad de la asociación; y la prueba de Kruskal-Wallis para medir las puntuaciones de nivel ordinal; p<0,05. Resultados La muestra tenía una edad media de 64,29±4,55 años, con un mayor número de personas de edad avanzada en un grupo pre-anciano (61,90 %), seguido por los ancianos recientes (26,37 %), los de edad media (10,47 %) y los ancianos de la edad avanzada (1,26 %). El procedimiento estadístico de análisis de cluster resultó viable para la identificación y validación de indicadores de salud de personas de edad avanzada. Al determinar el grado de correlación de variables, las pruebas no paramétricas, correlación de Spearman (p=0,0188) mostró una correlación estadísticamente significativa, y la prueba de Kruskal-Wallis (p=0,0018) fue altamente significativa (H=15,0230).Conclusión Los resultados muestran la eficacia y fiabilidad del uso de variables antropométricas y fisiológicas en el proceso de clasificación de los indicadores para la construcción de índices de salud.

Why are there race/ethnic differences in adult body mass index-adiposity relationships? A quantitative critical review

Body mass index (BMI) is now the most widely used measure of adiposity on a global scale. Nevertheless, intense discussion centers on the appropriateness of BMI as a phenotypic marker of adiposity across populations differing in race and ethnicity. BMI-adiposity relations appear to vary significantly across race/ethnic groups, but a collective critical analysis of these effects establishing their magnitude and underlying body shape/composition basis is lacking. Accordingly, we systematically review the magnitude of these race-ethnic differences across non-Hispanic (NH) white, NH black and Mexican American adults, their anatomic body composition basis and potential biologically linked mechanisms, using both earlier publications and new analyses from the US National Health and Nutrition Examination Survey. Our collective observations provide a new framework for critically evaluating the quantitative relations between BMI and adiposity across groups differing in race and ethnicity; reveal new insights into BMI as a measure of adiposity across the adult age-span; identify knowledge gaps that can form the basis of future research and create a quantitative foundation for developing BMI-related public health recommendations.

Derivation and validation of simple anthropometric equations to predict adipose tissue mass and total fat mass with MRI as the reference method

The reference organ-level body composition measurement method is MRI. Practical estimations of total adipose tissue mass (TATM), total adipose tissue fat mass (TATFM) and total body fat are valuable for epidemiology, but validated prediction equations based on MRI are not currently available. We aimed to derive and validate new anthropometric equations to estimate MRI-measured TATM/TATFM/total body fat and compare them with existing prediction equations using older methods. The derivation sample included 416 participants (222 women), aged between 18 and 88 years with BMI between 15·9 and 40·8 (kg/m2). The validation sample included 204 participants (110 women), aged between 18 and 86 years with BMI between 15·7 and 36·4 (kg/m2). Both samples included mixed ethnic/racial groups. All the participants underwent whole-body MRI to quantify TATM (dependent variable) and anthropometry (independent variables). Prediction equations developed using stepwise multiple regression were further investigated for agreement and bias before validation in separate data sets. Simplest equations with optimal R (2) and Bland-Altman plots demonstrated good agreement without bias in the validation analyses: men: TATM (kg)=0·198 weight (kg)+0·478 waist (cm)-0·147 height (cm)-12·8 (validation: R 2 0·79, CV=20 %, standard error of the estimate (SEE)=3·8 kg) and women: TATM (kg)=0·789 weight (kg)+0·0786 age (years)-0·342 height (cm)+24·5 (validation: R (2) 0·84, CV=13 %, SEE=3·0 kg). Published anthropometric prediction equations, based on MRI and computed tomographic scans, correlated strongly with MRI-measured TATM: (R (2) 0·70-0·82). Estimated TATFM correlated well with published prediction equations for total body fat based on underwater weighing (R (2) 0·70-0·80), with mean bias of 2·5-4·9 kg, correctable with log-transformation in most equations. In conclusion, new equations, using simple anthropometric measurements, estimated MRI-measured TATM with correlations and agreements suitable for use in groups and populations across a wide range of fatness.

Does the visceral fat tissue show better correlation with the fatty replacement of the pancreas than with BMI?

OBJECTIVE

Obesity is a risk factor of fatty replacement of the pancreas. We aimed to investigate whether there is a better correlation between the visceral fat tissue and the fatty infiltration of the pancreas than with the BMI.

MATERIALS AND METHODS

One hundred-eighteen patients were visually divided into three groups according to the pattern of the fatty infiltration of the pancreas. Group 0 (n=70) has no fatty infiltration, Group 1 (n=23) has fatty infiltration on the head only, and Group 2 (n=25) has fatty infiltration on the entire pancreas. Additionally, the attenuation numbers (HU) were measured separately at the head, body and tail of the pancreas on contrast-enhanced Computed Tomography CT. The sum of the attenuation number of each part of the pancreas was calculated as the attenuation number of the pancreas. A CT-scan was used to calculate the visceral fat area (cm(2)). Correlation coefficients were determined between the visceral fat area and fatty infiltration of the pancreas and the BMI.

RESULTS

The visceral fat area showed a stronger correlation with the attenuation number of the pancreas than the BMI (r=-0.552, r=-0.345 and p=0.0001, p=0.0001, respectively). The difference existed between the Groups 0 and 1 (p=0.0001) or Groups 0 and 2 (p=0.0001) in terms of visceral fat area. The difference existed only between Group 0 and Group 2 in terms of BMI (p=0.006).

CONCLUSIONS

The visceral fat tissue area has a stronger correlation than the BMI in the fatty infiltration of the pancreas.

Validation study of the body adiposity index as a predictor of percent body fat in older individuals: findings from the BLSA

A new body adiposity index (BAI = (hip circumference)/((height)(1.5)) - 18) has been developed and validated in adult populations. We aimed to assess the validity of BAI in an older population. We compared the concordance correlation coefficient between BAI, body mass index (BMI), and percent body fat (fat%; by dual-energy X-ray absorptiometry) in an older population (n = 954) participating in the Baltimore Longitudinal Study of Aging. BAI was more strongly correlated with fat% than BMI (r of .7 vs .6 for BAI vs BMI and fat%, respectively, p < .01) and exhibited a smaller mean difference from fat% (-5.2 vs -7.6 for BAI vs BMI and fat%, respectively, p < .01) indicating better agreement. In men, however, BMI was in better agreement with fat% (r of .6 vs .7 for BAI vs BMI and fat%, respectively, p < .01) with a smaller mean difference from fat% (-3.0 vs -2.2 for BAI vs BMI and fat%, respectively, p < .01). Finally, BAI did not accurately predict fat% in people with a fat% below 15%. BAI provides valid estimation of body adiposity in an older adult population; however, BMI may be a better index for older men. Finally, BAI is not accurate in people with extremely low or high body fat percentages.

Waist circumference-to-height ratio predicts adiposity better than body mass index in children and adolescents

OBJECTIVE

Body mass index (BMI) is the surrogate measure of adiposity most commonly employed in children and adults. Waist circumference (WC) and the waist circumference-to-height ratio (WCHt) have been proposed as markers of adiposity-related morbidity in children. However, no study to date has compared WCHt, WC, BMI and skinfolds thickness for their ability to detect body adiposity.

AIM

To compare WCHt, WC, BMI and skinfolds for their accuracy in predicting percent body fat (PBF), percent trunk fat (PTF) and fat mass index (FMI) in a large sample of children and adolescents.

DESIGN, SETTING AND PARTICIPANTS

We studied 2339 children and adolescents aged 8-18 years from the US National Health and Nutrition Examination Survey 2003/2004. Body fat was measured using dual-energy X-ray absorptiometry. Multivariable regression splines were used to model the association between PBF, PTF, FMI and the predictors of interest.

RESULTS

WCHt alone explained 64% of PBF variance as compared with 31% for WC, 32% for BMI and 72% for the sum of triceps and subscapular skinfolds (SF2) (P<0.001 for all). When age and gender were added to the predictors, the explained variance increased to 80% for the WCHt model, 72% for the WC model, 68% for the BMI model and 84% for the SF2 model. There was no practical advantage to add the ethnic group as further predictor. Similar relationships were observed with PTF and FMI.

CONCLUSIONS

WCHt is better than WC and BMI at predicting adiposity in children and adolescents. It can be a useful surrogate of body adiposity when skinfold measurements are not available.

Lifestyle factors of smoking, BMI and alcohol on the risk of Non-Melanoma Skin Cancer in adults: a systematic review

BACKGROUND

Non-melanoma skin cancer is the most common cancer in humans and the most important risk factors are thought to be age, skin type, and exposure to ultraviolet radiation. Lifestyle factors may also play a part. To date no systematic review has been performed to collate evidence of the effects of smoking, alcohol or body mass index.

OBJECTIVES

We performed a systematic review and meta-analysis to assess the effects of smoking, alcohol and body mass index on the risk of non-melanoma skin cancer and its subtypes.

INCLUSION CRITERIA

Adults (18+ years old) of either sex from any ethnicitySmoking, alcohol, or body mass index (including other anthropometric measurements, such as weight, waist to hip ratio, and the percentage body fat)Non-melanoma skin cancer, cutaneous squamous cell carcinoma, or basal cell carcinomaComparative observational epidemiological studies SEARCH STRATEGY: We performed a comprehensive search of MEDLINE, EMBASE, CINAHL, Cochrane Library and CAB Abstracts from inception to October 2010. We also scanned reference lists to identify further eligible studies.

METHODOLOGICAL QUALITY

Data from eligible studies were extracted and quality assessed using the Newcastle Ottawa Scale independently by two reviewers.

DATA COLLECTION

The titles, abstracts and full text identified from the search were assessed independently by two reviewers against pre-specified inclusion/exclusion criteria. Disagreements were resolved through discussion with a third reviewer.

DATA SYNTHESIS

For studies with similar exposures, a meta-analysis was performed using a random effects model and results were expressed as pooled odds ratio with 95% confidence intervals. Heterogeneity was assessed using I. Publication bias was assessed using funnel plots. Data were analysed using Review Manager.

RESULTS

Thirty studies were included of which 22 used a case control design and the remaining used a cohort design. The overall quality of the studies was variable with a Newcastle Ottawa Scale median score of 6 out of 9 stars. No evidence of asymmetry was detected in the funnel plots. Smoking was not significantly related to increased risks of non-melanoma skin cancer (Odds Ratio 0.62, 95% CI 0.21 to 1.79, I=34%, 2 studies) or basal cell carcinoma (Odds Ratio 0.95, 95% CI 0.82 to 1.09; I=59%, 14 studies). However, smoking was significantly associated with a 52% increase in the risk of cutaneous squamous cell carcinoma (95% CI 1.15 to 2.01; I=64%; 6 studies). Subgroup analysis found no significant difference in results based on the definition of smoking (current, former, or ever smoker) for basal cell carcinoma, cutaneous squamous cell carcinoma or non-melanoma skin cancer. Alcohol was not significantly related to increased risks of non-melanoma skin cancer (1 study), basal cell carcinoma (Odds Ratio 1.03, 95% CI 0.94 to 1.13, I=0%, 9 studies) or cutaneous squamous cell carcinoma (1 study). Similar results were found irrespective of the type of alcohol assessed (beer, wine, or spirits) for basal cell carcinoma and cutaneous squamous cell carcinoma. A pooled analysis of five studies found a non-significant decrease in the risk of basal cell carcinoma associated with a higher body mass index (Odds Ratio 0.94, 95% CI 0.84 to 1.04, I=40%). In a subgroup analysis based on sex, the potential reduction in risk of basal cell carcinoma appeared to be confined to males (Males: Odds Ratio 0.90, 95% CI 0.78 to 1.04, I=45%, 4 studies; Females: Odds Ratio 1.01, 95% CI 0.85 to 1.19, I=14%, 3 studies).

CONCLUSION

It is unclear at present if smoking modifies the risk of basal cell carcinoma; however, smoking clearly increases the risk of cutaneous squamous cell carcinoma. Limited evidence has been published about the risk of non-melanoma skin cancer with alcohol and body mass index; however there is some suggestion a high body mass index may be slightly protective of basal cell carcinoma, particularly in males.This study highlights the importance for clinicians to actively survey high risk patients, including current smokers.The majority of studies included in this systematic review assessed the associations between basal cell carcinoma and smoking, alcohol or body mass index. However, more evidence is needed before conclusive recommendations can be formed regarding the relationship between cutaneous squamous cell carcinoma and alcohol or body mass index.

Antioxidant biomarkers and food intake in elderly women

OBJECTIVE

To investigate the relationship between antioxidant biomarkers and food intake in elderly women.

DESIGN

Cross-sectional study.

SETTING

Recreation Center for the Elderly in the city of Itajaí, Santa Catarina, Brazil.

PARTICIPANTS

73 elderly women with an average age of 71 years, 93% caucasian, average body weight 68.7 ± 13.1 kg and average BMI 28.5 ± 2.3 kg/m².

MEASUREMENTS

Nutritional status was assessed based on the Body Mass Index (BMI). Data on food intake were obtained by applying the 24h diet recall method in three non-consecutive days, including Sunday. The assessment of antioxidant biomarkers was performed based on tests for total plasma thiols and phenolic compounds. The linear regression analysis was used to assess the effect of the consumption of food groups on antioxidant biomarkers.

RESULTS

A positive association was found between thiols and intake of carotenoid-rich vegetables (p=0.03), oils, fats and oilseeds (p=0.03); a negative association was observed between total concentrations of phenolic compounds and intake of cereals (p=0.04).

CONCLUSION

The intake of foods from the carotenoid-rich vegetables, oils, fats and oilseeds food groups increased the levels of plasma thiols, and the intake of foods from the group of cereals decreased the plasma concentration of phenols. Studies should be conducted to investigate the association between the intake of antioxidant-rich foods and the plasma antioxidant profile, as a way to protect against the aging process.

Direct relationship of body mass index and waist circumference with body tissue distribution in elderly persons

OBJECTIVES

To explore the relationship of BMI and WC with muscle/adipose tissue mass ratios and with trunk adipose tissue distribution, based on an anatomical 5-compartment model, by dissection of cadavers of elderly persons.

DESIGN

Cross-sectional explorative study.

SETTING

Brussels Cadaver Analysis Study.

PARTICIPANTS

Cadavers of twenty-nine white Caucasian elderly persons (17 females and 12 males, aged 78.1±6.9 years).

MEASUREMENTS

Whole body and trunk composition were determined at the anatomical tissue-system level by direct dissection.

RESULTS

BMI and WC were significantly and positively related to absolute tissue masses in both sexes. Muscle tissue mass, adipose tissue mass and trunk internal adipose tissue mass correlated better with BMI (r-values between 0.68 and 0.89) than with WC (r-values between 0.49 and 0.71). BMI was significantly and inversely related with various muscle/adipose tissue ratios in both sexes (r-values between -0.54 and -0.68). WC correlated with muscle/adipose tissue ratios in females only (r-values between -0.55 and -0.64). BMI was also significantly related to trunk adipose tissue distribution in elderly females, but not in males. When comparing individual tissue proportions within and between adjacent BMI-classifications or WC categories, body composition varied considerably.

CONCLUSION

Our results show that BMI and WC are significantly related with adipose tissue mass and with several ratios of muscle to adipose tissue in elderly subjects. However, cautious clinical interpretation is warranted since important differences in tissue mass proportions were found in subjects with similar BMI and/or WC values.

Obesity and medicare expenditure: accounting for age-related height loss

To determine the relationship between BMI and Medicare expenditure for adults 65-years and older and determine whether this relationship changes after accounting for misclassification due to age-related height loss. Using a cross sectional study design, the relationship between BMI and fee-for-service Medicare expenditure was examined among beneficiaries who completed the Medicare Current Beneficiary Survey (MCBS) in 2002, were not enrolled in Medicare Health Maintenance Organization, had a self-reported height and weight, and were 65 and older (n = 7,706). Subjects were classified as underweight, normal weight, overweight, obese (obese I), and severely obese (obese II/III). To adjust BMI for the artifactual increase associated with age-related height loss, the reported height was transformed by adding the sex-specific age-associated height loss to the reported height in MCBS. The main outcome variable was total Medicare expenditure. There was a significant U-shaped pattern between unadjusted BMI and Medicare expenditure: underweight $4,581 (P < 0.0003), normal weight $3,744 (P < 0.0000), overweight $3,115 (reference), obese I $3,686 (P < 0.0039), and obese II/III $4,386 (P < 0.0000). This pattern persisted after accounting for height loss: underweight $4,640 (P < 0.0000), normal weight $3,451 (P < 0.0507), overweight $3,165 (reference), obese I $3,915 (P < 0.0010), and obese II/III $4,385 (P < 0.0004) compared to overweight. In older adults, minimal cost is not found at "normal" BMI, but rather in overweight subjects with higher spending in the obese and underweight categories. Adjusting for loss-of-height with aging had little affect on cost estimates.

[Obesity prevalence and associated factors in the elderly in Pelotas, Rio Grande do Sul State, Brazil: obesity classification according to two cutoff points for body mass index]

The aim of this study was to estimate obesity prevalence and associated factors in the elderly, according to two cutoff points for body mass index (BMI). This was a cross-sectional, population-based study of a sample of 596 elderly residents in Pelotas, southern Brazil. Nutritional status was evaluated through BMI based on self-reported weight and stature. Poisson multiple regression with hierarchical analysis was applied, with two dependent variables for definition of obesity: BMI > 27 kg/m(2) and BMI > or =30 kg/m(2), the cutoff points proposed by Lipschitz and the World Health Organization, respectively. Prevalence of obesity was 48.7% (95%CI: 44.6-52.7) for BMI > 27 kg/m2 and 25.3% (95%CI: 21.9-29.0) for BMI > or =30 kg/m(2). Two multiple regression models showed an association between obesity and female gender and age. BMI > 27 kg/m(2) showed an association with age and smoking and BMI > or =30 kg/m(2) with sedentary lifestyle. Obesity prevalence was high in this group of elderly. For the Brazilian elderly population and from a public health perspective, the study suggests the use of a more sensitive cutoff point, namely BMI > 27 kg/m(2).

Obesity in the Elderly

OBJECTIVE

Clinical review of the epidemiology, morbidity, mortality, medical and economic costs of being overweight or obese; recommendations on obesity from the National Institutes of Health; and how these factors relate to the elderly.

DATA SOURCES

Medline search was used to identify relevant articles. Additional references were found in review articles and consensus guidelines.

STUDY SELECTION

Fifty-nine articles were identified and 40 were selected based on findings related to geriatric patients or obesity overall. Studies done in the United States as well as in European populations were included.

DATA EXTRACTION

Data were abstracted per findings for: epidemiology of being overweight and obese for adults and elderly, mortality and morbidity of being overweight or obese, issues with weight loss in the elderly, changes in physiology with aging that may impact on weight, whether increased body mass index (BMI) is directly associated with mortality in the elderly, whether the National Institutes of Health guidelines for BMI in obesity should be applied to elderly persons, mortality associated with weight, and costs of obesity.

DATA SYNTHESIS

The main findings suggest that being underweight results in a higher mortality for elderly persons as compared with being overweight.

CONCLUSION

The primary conclusion is that it is still not yet defined if the elderly should be held to the NIH standards for "overweight" and "obesity." More research is needed to determine if overweight and obese elderly benefit from weight loss measures or if they should be kept at their current weight.

Change in body mass index is a stronger predictor of change in fat mass than lean mass in elderly black and white women

The aim of this study was to determine the relation between change in body mass index (BMI) and changes in fat mass (FM), lean soft tissue (LST), and percentage body fat (%Fat) in elderly (67.6 +/- 6.0 years) women varying in race (53 black, 144 white) who underwent measurements of BMI, FM, LST, and %Fat at baseline and after 2 years. The group did not markedly change body composition over 2 years (BMI = -0.1 +/- 1.5 kg/m(2), P = 0.53; FM = 0.0 +/- 2.8 kg, P = 0.95; LST = -0.4 +/- 1.7 kg, P < 0.001; %Fat = 0.3 +/- 2.0%, P = 0.06). Change in BMI predicted change in FM (r = 0.90, SEE = 1.19 kg FM, P < 0.001) but was less predictive of change in %Fat (r = 0.64, SEE = 1.54%Fat, P < 0.001). Change in BMI was curvilinearly related to change in LST adjusted for change in height (R = 0.76, SEE = 1.10 kg LST, P < 0.001). Change in BMI more strongly predicts change in FM than LST and could be used to monitor change in FM in community-dwelling women.

Avaliação nutricional e prevalência de doenças crônicas não transmissíveis em idosos pertencentes a um programa assistencial

Objetivou-se avaliar o estado nutricional e a prevalência de doenças crônicas não transmissíveis em idosos que participavam de um programa assistencial da Universidade Federal de Alfenas (UNIFAL-MG), Alfenas, MG, Brasil. Foram coletadas variáveis socioeconômicas, antropométricas, bioquímicas e pressão arterial sistêmica de 82 indivíduos de 60 a 87 anos, sendo 90,2% do sexo feminino. Encontrou-se 52,4% de sobrepeso, 28,0% de eutrofia e 19,5% de baixo peso pelo IMC e 37,8% apresentaram percentual de gordura corpórea (%GC) elevada. Relacionando-se Índice de Massa Corpórea (IMC) com %GC, 63,4% dos idosos com sobrepeso, 12,5% dos eutróficos e 11,8% dos com baixo peso apresentavam %GC elevado. A razão da circunferência da cintura e do quadril (RCQ) revelou 40,2% em risco alto e 12,2% em risco muito alto para o desenvolvimento de doenças cardiovasculares. Quanto à pressão arterial, 22,0% eram hipertensos. Em relação aos exames bioquímicos, observou-se que 39,3%, 39,3% e 3,3% dos idosos apresentavam valores plasmáticos elevados de colesterol, triglicerídeos e glicose, respectivamente. Programas de educação nutricional continuada e de monitoramento do estado nutricional e de saúde são necessários para melhoria da qualidade de vida destes indivíduos estudados.

[Nutritional risk in surgery evaluated by body mass index adjusted or not to elderly patients]

BACKGROUND

Standard body mass index cut-off points for malnutrition are routinely used for adults independently of their age. The hypothesis of this study was that a cut-off point higher than the usual for the diagnosis of malnutrition might be more precise to access the nutritional risk of aged surgical patients.

AIM

To evaluate the morbimortality in aged surgical patients and its association with nutritional status assessed by body mass index using either the standard and a higher cut-off point for malnutrition.

PATIENTS AND METHODS

All patients admitted for operative procedures (n = 1,912) were allocated to either two groups: <65 years (n = 1,627) or >65 years old (n = 285). The body mass index was used to access the nutritional status. Two different cut-off points for malnutrition (18.5 or 24 kg/m(2)) were used in the group of older patients. Endpoints of the study were length of stay, morbidity and mortality.

RESULTS

Length of stay was higher in patients over 65 years (6 [1-75] days vs. 4 [1-137] days). Both postoperative complications (37/285; 13.0% vs. 109/1627; 6.7%; OR 2.1; IC95% 1.40-3.09) and deaths (15/285; 5.3% vs. 34/1627; 2.1%; OR 2.6; IC95% 1.40-4.84) were most common in the older group. Using a higher cut-off (24 kg/m(2)), the length of stay (8 [1-75] days vs. 4 [1-43] days), postoperative complications (28/152; 18.4% versus 9/133; 6.8%; OR 3,1; IC95% 1.41-6.86) and re-operations (16/152; 10.5% versus 3/133; 2.2%; OR 5.1; IC95% 1.45-17.91) were greater in malnourished patients. However these correlations were not statistically significant with the cut-off point for malnutrition in 18.5 kg/m(2).

CONCLUSIONS

Morbimortality is higher in surgical patients over 65 years old. In these, the cut-off point set in 24 kg/m(2) was most associated with the occurrence of postoperative complications, re-operations and length of stay.

Evaluation of air-displacement plethysmography and bioelectrical impedance analysis vs dual-energy X-ray absorptiometry for the assessment of fat-free mass in elderly subjects

OBJECTIVE

To evaluate air-displacement plethysmography (ADP) and bioelectrical impedance analysis (BIA) vs dual-energy X-ray absorptiometry (DXA) for the assessment of fat-free mass (FFM) in healthy elderly subjects.

SUBJECTS

Forty-two women and twenty-six men aged 60-84 years.

METHODS

FFM was measured by DXA and ADP. Body impedance (Z) was measured by four-polar BIA and the impedance index (ZI) was calculated as stature(2)/Z. Selection of predictors (gender, age, weight and ZI at 5, 50 and 100 kHz) for BIA algorithms was carried out using bootstrapped stepwise linear regression on 1000 samples of 68 subjects. Limits of agreement were used as measures of interchangeability of ADP and BIA with DXA.

RESULTS

The limits of agreement of ADP vs DXA were -11.0 to 2.4 kg in males and -4.8 to 2.2 kg in females. Gender, weight and ZI(100) were selected as predictors of FFM by bootstrapped stepwise linear regression. In males, ZI(100) (-12.2 to 12.2 kg) was much less accurate than weight (-6.0 to 6.0 kg) at predicting FFM and their combination did not improve the estimate (-6.0 to 6.0 kg). In females, ZI(100) (-6.8 to 6.8 kg) was less accurate than weight (-5.6 to 5.6 kg) at predicting FFM and their combination improved the estimate only slightly (-5.0 to 5.0 kg).

CONCLUSIONS

In healthy elderly subjects, (1) ADP and DXA are not interchangeable for the assessment of FFM, especially in males; and (2) ZI(100) is not superior to weight for the prediction of FFM and their combination is of little advantage and only in females.

Measurement of the distance and angle between the aorta and superior mesenteric artery: normal values in different BMI categories

AIM

The purpose of the study was to reveal the values of the distance and angle between the superior mesenteric artery (SMA) and aorta according to body mass index in normal population.

MATERIAL AND METHODS

The study was performed on 524 routine abdominal CT examinations. On axial and reformatted sagittal-oblique sagittal images, the distance and the angle between superior mesenteric artery (SMA) and aorta were measured at the location where the duodenum crosses. Body mass index (BMI, Kg/m(2)) was calculated. The cases were divided into four groups according to the BMI categories (Group 1: BMI<18.5, Group 2: BMI 18.5-24.9, Group 3: BMI 25-29.9, Group 4: BMI>30) in both genders. For each gender group, mean values of distance and angle measurements were calculated with standard deviations and 95% confidence intervals. For each gender group, Pearson correlation coefficients were calculated between the distance and BMI, as well as between the angle and BMI. Spearman correlation coefficients were calculated between the distance and BMI category, as well as between the angle and BMI category.

RESULTS

For both genders, there was a moderate and significant positive correlation between the distance and BMI. The correlation between the angle and BMI was low, but significant and positive (P < 0.001). The correlations between the BMI category and aortomesenteric distance or angle were moderate and significantly positive, as well (P < 0.001).

CONCLUSION

The aortomesenteric angle and distance significantly correlate with BMI in normal population. The mean values, we report, may be used as normal values to help reach the diagnosis of superior mesenteric artery syndrome.

The Fatty Liver Index: a simple and accurate predictor of hepatic steatosis in the general population

Background

Fatty liver (FL) is the most frequent liver disease in Western countries. We used data from the Dionysos Nutrition & Liver Study to develop a simple algorithm for the prediction of FL in the general population.

Methods

216 subjects with and 280 without suspected liver disease were studied. FL was diagnosed by ultrasonography and alcohol intake was assessed using a 7-day diary. Bootstrapped stepwise logistic regression was used to identify potential predictors of FL among 13 variables of interest [gender, age, ethanol intake, alanine transaminase, aspartate transaminase, gamma-glutamyl-transferase (GGT), body mass index (BMI), waist circumference, sum of 4 skinfolds, glucose, insulin, triglycerides, and cholesterol]. Potential predictors were entered into stepwise logistic regression models with the aim of obtaining the most simple and accurate algorithm for the prediction of FL.

Results

An algorithm based on BMI, waist circumference, triglycerides and GGT had an accuracy of 0.84 (95%CI 0.81–0.87) in detecting FL. We used this algorithm to develop the "fatty liver index" (FLI), which varies between 0 and 100. A FLI < 30 (negative likelihood ratio = 0.2) rules out and a FLI ≥ 60 (positive likelihood ratio = 4.3) rules in fatty liver.

Conclusion

FLI is simple to obtain and may help physicians select subjects for liver ultrasonography and intensified lifestyle counseling, and researchers to select patients for epidemiologic studies. Validation of FLI in external populations is needed before it can be employed for these purposes.

Dual energy X-ray absorptiometry body composition and aging in a population-based older cohort

OBJECTIVE

The aims of this cross-sectional study were (1) to examine the effect of age on body composition in older adults using dual-energy X-ray absorptiometry (DXA) and (2) to evaluate the agreement of DXA with standard indirect anthropometric measures (body mass index (BMI), waist circumference and waist-to-hip ratio (WHR)).

RESEARCH METHODS AND PROCEDURES

A population-based sample of 731 adults aged between 50 and 79 years underwent measurement of BMI, waist circumference, WHR, DXA total body fat mass, DXA % total body fat, DXA % trunk fat and DXA lean body mass. Linear regression was used to test for trend in measures of body composition between age categories in men and women. Partial correlations and Bland-Altman analysis were used to examine the agreement of DXA measures with indirect measures.

RESULTS

DXA lean body mass decreased significantly with increasing age in both sexes (P<0.05). In males, BMI (P=0.01) and body weight (P<0.01) decreased with age, and in females, WHR (P=0.05), DXA % total fat (P=0.02) and DXA % trunk fat (P=0.05) increased with age. There was good agreement between DXA measures of fatness and indirect anthropometric measures, except for WHR, which showed greater variability in its comparisons with DXA.

CONCLUSION

Using the highly sensitive and direct DXA method of measuring body composition, a decline in lean body mass and an increase in adiposity was observed with aging. Except for WHR, indirect anthropometric measures generally showed high levels of agreement with DXA fat measures in this older cohort.

Waist circumference correlates with metabolic syndrome indicators better than percentage fat

OBJECTIVE

Percent fat is often considered the reference for establishing the magnitude of adipose tissue accumulation and the risk of excess adiposity. However, the increasing recognition of a strong link between central adiposity and metabolic disturbances led us to test whether waist circumference (WC) is more highly correlated with metabolic syndrome components than percent fat and other related anthropometric measures such as BMI.

RESEARCH METHODS AND PROCEDURES

BMI, WC, and percent fat, measured by DXA, were evaluated in 1010 healthy white and African-American men and women [age, 48.3 +/- 17.2 (standard deviation) years; BMI, 27.0 +/- 5.3 kg/m(2)]. The associations of BMI, WC, and percent fat with age and laboratory-adjusted health risk indicators (i.e., serum glucose, insulin, triglycerides, high-density lipoprotein cholesterol, blood pressure) in each sex and ethnicity group were examined.

RESULTS

For 18 of 24 comparisons, the age- and laboratory-adjusted correlations were lowest for percent fat and in 16 of 24 comparisons were highest for WC. Fifteen of the between-method differences reached statistical significance. With health risk indicator as the dependent variable and anthropometric measures as the independent variable, the contribution of percent fat to the WC regression model was not statistically significant; in contrast, adding WC to the percent fat regression model did make a significant independent contribution for most health risk indicators.

DISCUSSION

WC had the strongest associations with health risk indicators, followed by BMI. Although percent fat is a useful measure of overall adiposity, health risks are best represented by the simply measured WC.

Definition of needle length required for intramuscular deltoid injection in elderly adults: an ultrasonographic study

An ultrasound study in elderly patients (> or =65 years) showed that body mass index (BMI) was strongly correlated with deltoid subcutaneous layer thickness in males (r = 0.69 dominant arm, 0.71 non-dominant arm) and females (r = 0.79 both arms). Females with the same BMI as males had significantly thicker subcutaneous layers (p = 0.0001) and thinner muscle layers (p = 0.0003). Minimal needle length required for deltoid intramuscular injection where the needle was entered at 90 degrees to the long axis of the humerus was defined by BMI group. In all BMI males and females, BMI <35, intramuscular injection could be achieved with a 25 mm long needle, whilst in females BMI >35, a 32 mm long needle is required. These data will be used in studies to resolve the clinical equipoise regarding the optimal route of administration (intramuscular versus subcutaneous) of vaccines (e.g. influenza and pneumococcal vaccines), which are provided through public health programs for the elderly.

Is the current BMI obesity classification appropriate for black and white postmenopausal women?

OBJECTIVE

To evaluate the relation between body fatness (%Fat) and body mass index (BMI) and to evaluate the validity of the BMI standards for obesity established by the NIH in older black and white postmenopausal women.

RESEARCH METHODS

Height, weight, BMI, and %Fat, assessed by DXA, were determined for 296 healthy, independently living women ranging in age from 50 to 80 years (M+/-s.d.; 64.4+/-7.8 years).

RESULTS

Per NIH guidelines, 32% were classified as obese (> or = 30 kg/m2, mean BMI = 28.1+/-5.5 kg/m2). In contrast, using the %Fat criterion of 38% advocated by Lohman to define obesity, 47% of our sample was obese (mean %Fat=37.3+/-6.2%). A moderately high curvilinear relation existed between BMI and %Fat (R = 0.82, SEE = 3.57 %Fat, P<0.05). Race added meaningfully to the prediction of %Fat (P<0.05) such that for the same BMI, black women will have 1% lower body fatness than white women. Based on a %Fat > or = 38 as the criterion for obesity, receiver operating characteristic (ROC) analysis, performed separately by race, indicated that the currently accepted BMI cutpoint for obesity produced low sensitivity (69% and 61% for black and white women, respectively). Alternatively, BMI values > or = 28.4 kg/m2 for black women and > or = 26.9 kg/m2 for white women to define obesity maximized classification accuracy.

CONCLUSION

We conclude that current BMI categories may not be appropriate for identifying obesity among postmenopausal women. Furthermore, the relation between BMI and %Fat is different in black compared to white women but remains constant from the sixth through the eighth decade of life.

Rapid automated measurement of body fat distribution from whole-body MRI

OBJECTIVE

The purpose of this article is to determine the feasibility of using computer-assisted diagnosis (CAD) techniques to automatically identify, localize, and measure body fat tissue from a rapid whole-body MRI examination.

CONCLUSION

Whole-body MRI in conjunction with CAD allows a fast, automatic, and accurate approach to body fat measurement and localization and can be a useful alternative to body mass index. Whole-body fat analysis can be achieved in less than 5 min.

[Body mass index and measures of adiposity among elderly adults]

OBJECTIVE

To evaluate the nutritional status of elderly persons and to compare the correlation between the body mass index (BMI=kg/m2) with measures of adiposity and fat distribution among elderly and middle-aged adults.

METHODS

Elderly persons (N=699; 60 years or older) and middle-aged adults (N=1,306; 40-59.9 years) participating in a population-based survey conducted in 1996 in the municipality of Rio de Janeiro were evaluated as to body mass index, arm, waist, and hip circumferences, skinfolds, and arm fat and muscle areas using standardized procedures. The cutoff points proposed by the World Health Organization for waist circumference, waist-to-hip ratio, and body mass index were used. Analyses were performed using the Spearman correlation coefficient and linear regression adjusted for age.

RESULTS

About 50% of elderly subjects were classified as overweight and more than 50% of women in all age groups had waist circumference and waist-to-hip ratio outside the normal range. Among men, these percentages were about 40% for waist circumference and 20% for waist-to-hip ratio. Among elderly subjects, the partial correlation (adjusted for age) between body mass index and measures of adiposity (waist circumference, skinfolds, and arm fat area) ranged from 0.45 to 0.85 for men and 0.55 to 0.86 for women. Weight and waist circumference were the variables more strongly correlated with body mass index among both elderly persons and adults.

CONCLUSIONS

The prevalence of overweight among elderly persons was high for both men and women. Body mass index shows a similar relationship with adiposity regardless of ageing.

Prevalence and Secular Trends of Excess Body Weight and Impact on Outcomes After Myocardial Infarction in the Community

OBJECTIVES

To determine the trends in the prevalence of overweight and obese individuals among patients with myocardial infarction (MI), and to assess the association between weight and outcomes after MI.

DESIGN

Population-based cohort study.

METHODS

MIs occurring in Olmsted County, MN, between 1979 and 1998 were validated using standardized criteria. Clinical characteristics and outcomes were ascertained from community medical records. The prevalence and trends of excess weight and its association with outcomes were analyzed.

RESULTS

Sixty-four percent of the 2,277 subjects with incident MI were overweight or obese. The prevalence of overweight/obese patients increased from 58% in the period from 1979 to 1983, to 72% in the period from 1994 to 1998 (p < 0.001), while the prevalence of class 3 obesity (body mass index >or= 40) increased from 0.6 to 4.4%. Overweight and obese patients were more likely to have diabetes, hypertension, familial coronary disease, and hyperlipidemia than persons with normal weight but less likely to have comorbidities (obstructive lung disease, heart failure, cancer, renal failure, and stroke) [all p values < 0.05]. When compared to patients with normal weight, after adjusting for age and other confounders, overweight and obese patients had a lower mortality (risk ratio [RR], 0.84; 95% confidence interval [CI], 0.73 to 0.96 for overweight; and RR, 0.85; 95% CI, 0.72 to 1.02 for obese) and a similar risk of cardiac events.

CONCLUSION

The prevalence of overweight and obese individuals among patients with MI is high and increased over time. Despite a higher prevalence of other cardiovascular risk factors among patients with excess weight, these patients did not experience worse outcomes, underscoring the need to further study the paradoxical relation between weight and post-MI outcomes.

Assessing the validity of body mass index standards in early postmenopausal women

OBJECTIVE

To examine the relationship between percentage of total body fat (%Fat) and body mass index (BMI) in early postmenopausal women and to evaluate the validity of the BMI standards for obesity established by the NIH.

RESEARCH METHODS AND PROCEDURES

Three hundred seventeen healthy, sedentary, postmenopausal women (ages, 40 to 66 years; BMI, 18 to 35 kg/m(2); 3 to 10 years postmenopausal) participated in the study. Height, weight, BMI, and %Fat, as assessed by DXA, were measured. Receiver operating characteristic analysis was performed to evaluate the ability of BMI to discriminate obesity from non-obesity using 38%Fat as the criterion value.

RESULTS

A moderately high relationship was observed between BMI and %Fat (r = 0.81; y = 1.41x + 2.65) with a SE of estimate of 3.9%. Eighty-one percent of other studies examined fell within 1 SE of estimate as derived from our study. Receiver operating characteristic analysis showed that BMI is a good diagnostic test for obesity. The cutoff for BMI corresponding to the criterion value of 38%Fat that maximized the sum of the sensitivity and specificity was 24.9 kg/m(2). The true-positive (sensitivity) and false-positive (1--specificity) rates were 84.4% and 14.6%, respectively. The area under the curve estimate for BMI was 0.914.

DISCUSSION

There is a strong association between %Fat and BMI in postmenopausal women. Current NIH BMI-based classifications for obesity may be misleading based on currently proposed %Fat standards. BMI >25 kg/m(2) rather than BMI >30 kg/m(2) may be superior for diagnosing obesity in postmenopausal women.