Relation between body composition and age in healthy Japanese subjects

Excess accumulation of body fat is related to dyslipidemia in normal-weight subjects

OBJECTIVE

To assess the relationship of fat mass (FM) and its distribution to hypertension and dyslipidemia in normal-weight Japanese individuals.

DESIGN

Cross-sectional study.

SUBJECTS

Apparently healthy Japanese subjects with a body mass index (BMI) between 20 and 23.5 kg/m(2) (265 males and 741 females, age 21-69 y).

MEASUREMENTS

BMI, waist circumference (WC), waist-hip ratio (WHR), systolic and diastolic blood pressure, serum levels of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) were measured. Low-density lipoprotein-cholesterol (LDL-C) was calculated by the Friedewald formula. Percentage fat mass (%FM) and trunk fat mass-leg fat mass ratio (FM(trunk)/FM(legs)) were obtained by dual-energy X-ray absorptiometry.

RESULTS

WC, WHR, %FM and FM(trunk)/FM(legs) were significantly correlated with TC, LDL-C, HDL-C and TG with the tendency of FM(trunk)/FM(legs) to show the strongest correlations. For %FM and FM(trunk)/FM(legs) in both sexes, odds ratios (ORs) of the third tertiles with respect to the first tertiles increased for LDL-C elevation, TG elevation and dyslipidemia. In males, ORs of the third tertiles of WC were significantly high for LDL-C elevation and dyslipidemia whereas those of WHR were high for TG elevation and dyslipidemia. ORs of the third tertiles of WC and WHR were significantly high for TG elevation in females. BMI was not associated with the risk of abnormal lipid levels. ORs for hypertension showed significant increases in none of the variables of obesity.

CONCLUSIONS

Excess accumulation of FM, especially to the upper body, was related to dyslipidemia in normal-weight subjects. Simple anthropometric variables, WC and WHR, may be useful for screening and management of dyslipidemia in these subjects.

Body composition measurements: interpretation finally made easy for clinical use

PURPOSE OF REVIEW

This review presents the latest clinical applications of bioelectrical impedance analysis. It discusses the evaluation of nutritional status by using fat-free mass and body fat, percentiles of fat-free mass and body fat, height-normalized fat-free mass and body fat mass indices and a resistance/reactance vector graph.

RECENT FINDINGS

Fat-free mass and body fat can be used to evaluate nutritional status by comparing individuals or groups of individuals with themselves or with reference values. Percentile distributions are also useful in determining whether individuals or groups fall within the population range. Percentile ranks can also be used to define nutritional depletion and obesity. The use of the fat-free mass and body fat mass indices has the advantage of compensating for differences in body height. The use of low, normal, high and very high fat-free mass and body fat mass indices ranges that correspond to underweight, normal, overweight and obese body mass index categories further aid in the nutritional assessment process. With vector bioelectrical impedance analysis, an individual impedance vector is compared with the 50, 75, and 95% tolerance ellipses calculated in the reference, healthy population, allowing evaluation in any clinical condition. More accurate estimates of conventional bioelectrical impedance analysis equations might be obtained in individuals with a normal impedance vector.

SUMMARY

The assessment of fat-free mass and body fat provides valuable information about changes in body composition with weight gain or loss and physical activity, and during ageing. The use of percentiles and height-normalized fat-free mass and body fat permit the classification of patients as under or overnourished.

Detection of cardiovascular risk factors by indices of obesity obtained from anthropometry and dual-energy X-ray absorptiometry in Japanese individuals

OBJECTIVE

To determine the cut-off points of indices of obesity for detecting hypertension, dyslipidemia and diabetes mellitus in Japanese individuals.

DESIGN

Cross-sectional study.

SUBJECTS

A total of 2728 Japanese individuals (768 males and 1960 females, aged 20-79 y) who attended the Fukuoka Health Promotion Center, Japan for health check-up.

MEASUREMENTS

Body mass index (BMI), waist circumference (WC) and waist-hip ratio (WHR) were measured. Percentage fat mass (%FM), trunk fat mass (FM(trunk)) and trunk fat mass-leg fat mass ratio (FM(trunk)/FM(legs)) were obtained by dual-energy X-ray absorptiometry (DXA). Cardiovascular risk factors were determined by blood pressure, serum lipids, fasting blood glucose and hemoglobin A(1C).

RESULTS

The cut-off points of BMI, WC and WHR were around 23.5 kg/m(2), 84 cm and 0.9 for males, and 22.5 kg/m(2), 72 cm and 0.8 for females. The cut-off points of %FM, FM(trunk) and FM(trunk)/FM(legs) were around 24%, 8 kg and 1.6 for males, and 35%, 9 kg and 1.4 for females. WHR and FM(trunk)/FM(legs) most accurately detected the risk factors.

CONCLUSIONS

For Japanese individuals, the cut-off points for detecting cardiovascular risk factors are lower than the criteria by the World Health Organization. Indices of fat distribution detected the cardiovascular risk factors more accurately than those of overall adiposity. The accuracy of detecting the risk factors was comparable between the anthropometric indices and indices obtained by DXA.

A adiposidade corporal e a idade prejudicam a capacidade funcional para realizar as atividades da vida diária de mulheres acima de 47 anos

Este estudo teve como objetivo verificar o efeito da idade, peso, altura, índice de massa corporal e adiposidade corporal na capacidade funcional de mulheres acima de 47 anos para realizar as atividades da vida diária. Para tanto, a amostra foi constituída por 129 mulheres na faixa etária de 47 a 77 anos de idade. A adiposidade total (Adp T) foi considerada por meio do somatório das dobras cutâneas bíceps (BI), tríceps (TRI), subescapular (SB), axilar média (AM), supra-ilíaca (SI), abdominal (ABD), coxa anterior (CA) e panturrilha medial (PM). A adiposidade central (Adp C) representou o somatório de SB, AM, SI e ABD, e a adiposidade periférica (Adp P), o somatório de BI, TRI, CA e PM. A capacidade funcional para realizar as atividades da vida diária foi predita mediante os testes: velocidade para se levantar de uma posição sentada (VLPS) e para se levantar de uma posição deitada (VLPD), velocidade para calçar e amarrar o tênis (VCAT) e velocidade para subir escada (VSE). Foi calculado o quartil (Q) para todas as variáveis independentes (idade, peso, altura, índice de massa corporal e adiposidade corporal [total, central e periférica]). A análise estatística utilizada foi a ANOVA one way e os coeficientes de correlação linear de Pearson e Spearman rank-order. As diferenças estatisticamente significativas ocorreram principalmente entre os quartis das extremidades (Q1 x Q4) para VLPS e VLPD (exceção para peso e IMC), enquanto para VSE foi entre Q2 x Q4 (idade). As variáveis independentes exerceram efeito nulo sobre VCAT. A magnitude de variação percentual ocorreu entre a amplitude de 14,1% (idade [VLPD: Q3 x Q4]) e 36,1% (Adp T [VLPS: Q2 x Q4]). Em ordem, as variáveis independentes que exerceram maior repercussão negativa sobre a performance nos testes de capacidade funcional (VLPS, VLPD, VSE) para realizar as atividades da vida diária foram Adp C, idade, Adp T, Adp P, IMC e peso.

Body composition: what's new?

PURPOSE OF REVIEW

Body mass index has been shown to be an imprecise measurement of fat-free and fat mass, and provides no information if weight changes occur as a result of a decrease in fat-free mass or an increase in fat mass.

RECENT FINDINGS

Non-invasive body composition methods (i.e. bioelectrical impedance analysis, air displacement plethysmography) can now be used to monitor fat-free and fat mass with weight gain and loss, and during aging. This review discusses body composition measurements in terms of ethnic differences, physical activity, and age, and the limitations of bedside techniques in obesity and abnormal hydration status.

SUMMARY

An assessment of the fat-free and fat mass provides valuable information about changes in body composition with weight gain or loss and physical activity, and during aging. Non-invasive bedside techniques can now be used to evaluate the nutritional status of healthy and ill individuals.