Measurement of body fat in healthy elderly men: a comparison of methods

BACKGROUND: Nutritional evaluation of elderly people is of great importance. Two-component methods for body composition assessment, such as anthropometry and bioelectrical impedance (BIA), are widely used in clinical practice, but their fundamental assumptions may be invalid in older people. Dual-energy X-ray absorptiometry (DXA) is a relatively new method for reliable and direct measurements of body mass in its three basic components: total body bone mineral content (TBBMC), mineral free lean tissue mass (LTM), and fat. In this study, percent body fat (%BF) estimates from anthropometry and BIA in men of various ages were compared with corresponding measurements by DXA. METHODS: Body fat percentage was estimated in 67 men aged 20-95 by anthropometric measurements (skinfold thickness, body mass index, or BMI), BIA, and DXA. Age-specific equations were used for anthropometry and BIA. Limits of agreement were calculated between DXA and the other methods. RESULTS: The equations based on BMI and BIA systematically overestimated %BF with respect to %BF measured by DXA in people of all ages. Intermethod difference between DXA and skinfold thicknesses was less marked, but in over-80-year-olds %BF predicted by skinfold measurements underestimated %BF measured by DXA. Interindividual and age-related variation in TBBMC and in fat-free mass mineralization could partly explain the intermethod differences found between DXA and the other methods. CONCLUSIONS: Because of practical constraints, anthropometry and BIA are often the only available options for body composition assessment in clinical routine; therefore, further research on the validity and improvement of these methods in older people is indicated.     

Interactions between serum leptin,the insulin-like growth factor-I system,and sex,age, anthropometric and body composition variables in a healthy population randomly selected

OBJECTIVE: Leptin secretion is influenced by many factors and the GH/IGF axis plays an important role in the regulation of body composition, but the physiological interactions between leptin and the IGF-I system remain unknown. In this study we investigated the relationship between leptin, the IGF-I system, and sex, age, anthropometric and body composition variables in a group of healthy adults randomly selected. DESIGN: A cross-sectional study. PATIENTS: The study included 268 subjects, representative of the whole population of the city of L'Hospitalet de Llobregat in sex and age distribution: 134 men aged 41.4 years, range 15-70 years; and 134 women, aged 40.7 years, range 15-70 years. MEASUREMENTS: Body mass index (BMI) was calculated, and body composition was determined by using a bioelectrical impedance analyser. Serum leptin concentrations were determined by using a radioimmunoassay (RIA). Serum total IGF-I concentrations, after acid-ethanol extraction, were also measured by RIA. Serum free IGF-I concentrations were determined by an enzymoimmunometric assay. Serum IGFBP3 concentrations were determined by RIA. Plasma basal TSH concentrations were determined by a specific electrochemiluminescence assay. RESULTS: In men the BMI was similar in all decades and waist/hip ratio increased in the last three decades. Fat-free mass decreased by decade. We observed an increase in leptin in the fourth decade with a decrease in IGF-I, free IGF-I and IGFBP3 throughout the decades. Basal TSH showed an increase in the last two decades. In women, BMI, waist/hip ratio and fat mass increased significantly in the last decades. Leptin concentrations increased in the last decades and total IGF-I, free IGF-I and IGFBP3 decreased by decade without changes in basal TSH concentration. In men, there was a positive correlation between leptin and BMI, waist/hip ratio, total body water, fat-free mass and fat mass, and these anthropometric and body composition variables showed a negative correlation with free IGF-I and IGFBP3, without any correlation with total IGF-I. In women, there was a positive correlation between leptin and BMI, waist/hip ratio, total body water, fat-free mass, and fat mass, which showed a negative correlation with total IGF-I and IGFBP3, without any correlation with free IGF-I. In men, total IGF-I was negatively correlated with waist/hip ratio without any correlation with the other variables and free IGF-I was negatively correlated with BMI and waist/hip ratio, and IGFBP3 did not show any correlation. In women, total IGF-I, free IGF-I and IGFBP3 were negatively correlated with BMI, waist/hip ratio and fat mass. The multiple linear regression analysis produced a model that explained 60.5% of leptin variability in men and 40% in women. Notably, only age, BMI, fat mass and waist/hip ratio brought an independent significant contribution to leptin variability. The final model also explained 28.2% and 60.4% of total IGF-I variability and 17.2% and 27.4% of free IGF-I variability in men and women, respectively. Age and leptin contributed to free IGF-I variability in men, and age and fat mass were significantly and independently associated with total IGF-I in women. CONCLUSIONS: In this well-characterized population of controls randomly selected without chronic disease or drug administration and with biochemically confirmed euthyroidism, we found that both men and women had a significant correlation between leptin levels and the IGF-I system, and anthropometric and body composition variables, but that leptin did not regulate the IGF-I system, and that the IGF-I system did not regulate leptin synthesis and secretion.     

Foot-to-foot bioelectrical impedance analysis: a valuable tool for the measurement of body composition in children.

OBJECTIVE: To determine the accuracy of foot-to-foot bioelectrical impedance analysis (BIA) and anthropometric indices as measures of body composition in children. DESIGN: Comparison of foot-to-foot BIA and anthropometry to dual-energy X-ray absorptiometry (DEXA)-derived body composition in a multi-ethnic group of children. SUBJECTS:: Eighty-two European, NZ Maori and Pacific Island children aged 4.9-10.9 y. MEASUREMENTS: DEXA body composition, foot-to-foot bioelectrical impedance, height, weight, hip and waist measurements. RESULTS: Using a BIA prediction equation derived from our study population we found a high correlation between DEXA and BIA in the estimation of fat-free mass (FFM), fat mass (FM) and percentage body fat (PBF) (r=0.98, 0.98 and 0.94, respectively). BIA-FFM underestimated DEXA-FFM by a mean of 0.75 kg, BIA-FM overestimated DEXA-FM by a mean of 1.02 kg and BIA-PBF overestimated DEXA-PBF by a mean of 2.53%. The correlation between six anthropometric indices (body mass index (BMI), ponderal index, Chinn's weight-for-height index, BMI standard deviation score, weight-for-length index and Cole's weight-for-height index) and DEXA were also examined. The correlation of these indices with PBF was remarkably similar (r=0.85-0.87), more variable with FM (r=0.77-0.94) and poor with FFM (r=0.41-0.75). CONCLUSIONS: BIA correlated better than anthropometric indices in the estimation of FFM, FM and PBF. Foot-to-foot BIA is an accurate technique in the measurement of body composition.     

Superiority of skinfold measurements and waist over waist-to-hip ratio for determination of body fat distribution in a population-based cohort of Caucasian Dutch adults

OBJECTIVE: To determine which anthropometric measurement is the most reliable alternative for fat distribution as measured by dual-energy X-ray absorptiometry (DXA). DESIGN: Population-based survey carried out in Amsterdam, The Netherlands. SUBJECTS AND METHODS: A total of 376 individuals (200 women) with a mean age of 36.5 years and mean body mass index (BMI) of 24.0 (+/-3.1) kg/m2 underwent various anthropometric and DXA measurements of central (CFM) and peripheral fat mass (PFM). Furthermore, for the assessment of apple-shaped body composition, CFM-to-PFM ratio was calculated. Anthropometric measurements were waist and hip circumference, waist-to-hip ratio (WHR), BMI, waist/length and the skinfold thickness of biceps, triceps, suprailiacal (SI), subscapular (SS) and upper leg. We determined whether equations of combined anthropometrics were even more reliable for the assessment of fat mass. RESULTS: In both women and men, reliable alternatives for CFM are central skinfolds and waist (Pearson's correlation (r) >or= 0.8). Peripheral skinfolds are the best predictors of PFM (r >or= 0.8). In contrast, WHR correlated only marginally with any of the DXA measurements. Equations based on several anthropometric variables correlate with CFM even better (R2 >or= 0.8). CFM-to-PFM ratio has the highest correlation with the ratio (SS+SI)/BMI in women (r = 0.66) and waist/length in men (r = 0.71). Equations are reasonable alternatives of CFM-to-PFM ratio (R2 >or= 0.5). CONCLUSION: Waist and skinfolds are reliable alternatives for the measurement of body fat mass in a cohort of Caucasian adults. WHR is not appropriate for the measurement of fat distribution.     

Fat distribution in European men: a comparison of anthropometric measurements in relation to cardiovascular risk factors.

It has been proposed that subcutaneous fat patterning assessed by skinfolds is measuring different aspects of fat distribution compared to circumferences and circumference ratios. In this study in 510 men born in 1950 selected from six European towns we compared the associations between five skinfolds, eight circumferences and several skinfold and circumference ratios and metabolic risk factors after adjustment for body mass index (BMI). All skinfolds were independently of BMI positively related to diastolic blood pressure. Waist circumferences at most levels were independently of BMI positively related to blood pressure and triglycerides and negatively to HDL-cholesterol. Circumferences at the levels of chest, hips, thigh and arm were not related to any of the risk factors studied. Waist/thigh ratios were generally more strongly and more consistently related to risk factors than waist/hip ratios. The partial correlations of anthropometric variables with risk factors were relatively weak and never exceeded r = 0.20. The results give an indication, however, that subcutaneous fat patterning is related to different risk factors compared to waist/hip ratios. Moreover, waist/thigh and waist circumference alone (measured either as the minimal circumference or midway between the lower rib margin and the iliac crest) were stronger correlates of cardiovascular risk factors compared to waist/hip ratio.     

Body fat distribution reference standards in Spanish adolescents: the AVENA Study

OBJECTIVE: To present body fat patterning reference standards to identify children with a predominant distribution of body fat in the abdominal or truncal region of the body. DESIGN: Cross-sectional study in a representative sample of Spanish adolescents aged 13-18 years. SUBJECTS: A total of 2160 adolescents with a complete set of anthropometric measurements (1109 males and 1051 females). MEASUREMENTS: Weight, height, body mass index, skinfold thickness (biceps, triceps, subscapular, suprailiac, thigh, calf) and waist and hip circumferences. RESULTS: In the majority of the age groups, subscapular/triceps skinfolds ratio, trunk-to-total skinfolds percent (TTS%)and waist circumference values were significantly higher in males than in females; hip circumference was higher in females than in males, except at 15.5 years. In males, age showed a significant effect for all the body fat distribution indices; however, in females, the effect was only significant for triceps skinfold, waist and hip circumferences and waist-to-hip ratio. Smoothed age- and sex-specific triceps skinfold, subscapular skinfold, subscapular/triceps skinfolds ratio, TTS%, waist circumference and hip circumference, waist-to-hip and waist-to-height ratio percentile values for male and female adolescents have been established. CONCLUSION: These reference data for waist circumference and the other fat patterning indices, together with data from other countries, will help to establish international central obesity criteria for adolescents. The presented percentile values will give the possibility to estimate the proportion of adolescents with high or low regional adiposity amounts.     

Comparison of methods for estimating body composition in young and elderly women

Estimates of percent body fat and fat-free mass (FFM) were made in healthy young and elderly female subjects using five different methods: bioelectrical impedance analysis (BIA); regression equations involving skinfold measurements at two (Durnin and Womersley; SKF-DW) or three (Jackson and Pollack; SKF-JP) sites; the body mass index (BMI); and an equation relating height and weight to total body water (TBW). Three of the five methods indicated that the percent body fat was significantly greater in the elderly age group. Similarly, three methods estimated FFM values that were significantly lower in the elderly group. In the young group the SKF-DW and TBW methods produced percent fat estimates significantly higher than the other three methods. In the elderly group the percent fat estimates were as follows: SKF-DW greater than BIA greater than SKF-JP = TBW greater than BMI. FFM estimates in both age groups were in inverse rank order to the percent fat estimates. In elderly subjects SKF-DW produced results closest to those from BIA, whereas in young subjects SKF-JP provided the best agreement with the BIA procedure.     

Comparison of ultrasonographic and anthropometric methods to assess body fat in childhood obesity

BACKGROUND: Pattern of fat distribution rather than obesity is of importance for cardiovascular morbidity and mortality. The accurate measurement of total and regional fat mass requires sophisticated and often expensive methods that have limited applicability in the clinical setting. OBJECTIVE: The aim of this study is to evaluate body fat distributions by ultrasound (US) as a gold standard method for measuring visceral, preperitoneal and subcutaneous fat layers and comparing with anthropometric results, and then to find the most reliable anthropometric measurement in childhood obesity. MATERIALS AND METHODS: Study group of 51 obese children (21 F, 30 M) (mean age+/-s.d.: 11.5+/-2.6 years) and control group of 33 non-obese children (17 F, 16 M) (mean age+/-s.d.: 12.2+/-2.7 years) were recruited for this study. Anthropometric measurements as body mass index (BMI), waist circumference (WC), waist/hip ratio (WHR), triceps and subscapular skinfold thicknesses were taken from all the participants. Abdominal preperitoneal (P), subcutaneous (S) fat at their maximum (max) and minimum (min) thickness sites, visceral (V), triceps (TrUS) and subscapular (SsUS) fat thicknesses were also measured ultrasonographically. RESULTS: In the obese group, BMI was significantly correlated with US measurements of fat thicknesses, except Pmin and SsUS, whereas in the control group, BMI was significantly correlated with all US fat measurements. The relation of US measurements with skinfold thickness and WC was more significant in the control than in the obese group. No relation between WHR and US fat thickness measurements was found in both groups. Multiple regression analysis, using V as the dependent variable and anthropometric parameters, gender and the group as the independent variables, revealed BMI was the best single predictor of V (R(2): 0.53). CONCLUSION: This study suggests that the validity of the anthropometric skinfold thickness in the obese children is low. Despite the limitations reported in the literature, in our study, BMI provides the best estimate of body fat. WHR in children and adolescents is not a good index to show intra-abdominal fat deposition.     

Anthropometry and body composition in ethnic Japanese and Caucasian adolescent girls: considerations on ethnicity and menarche

OBJECTIVE: This study aimed to compare the various anthropometric and body composition parameters based on the ethnicity and the absence or presence of menarche. DESIGN: A cross-sectional study with incomplete sampling, using the subject as the evaluation unit. SUBJECTS: The final sample of 550 subjects was composed of 122 Japanese and 179 Caucasian premenarcheal adolescents, and 72 Japanese and 177 Caucasian postmenarcheal adolescents. METHODS: The variables of body composition were measured through the following methods: bioelectrical impedance analysis, near-infrared interactance (NIR), Slaughter cutaneous skinfold equations and body mass index. Weight, height and sitting height were also evaluated. RESULTS: The Japanese pre- and postmenarcheal girls presented lower weight and height values when compared with the Caucasian girls. In general, the Japanese premenarcheal girls presented less fat and fat-free mass than the premenarcheal Caucasian girls. This fact was demonstrated through NIR results. Conversely, the Japanese postmenarcheal adolescents accumulated more fat than their Caucasian counterparts. However, significant differences were solely encountered in the values of cutaneous skinfold percent body fat. With regard to menarche, it was verified that, regardless of ethnicity, all the anthropometric and body composition variables reached higher values among postmenarcheal adolescents when compared with premenarcheal adolescents. CONCLUSION: Different results of weight and height between the ethnic groups may bring back the discussion concerning separate growth curves for different ethnic groups. The results of the body composition analysis indicated high adiposity levels among postmenarcheal adolescents.     

Body fat distribution in relation to serum lipids and blood pressure in 38-year-old European men: the European fat distribution study

A study on 512 38-year-old European men selected from 6 different towns was conducted. There were significant differences between the centers in averages of anthropometric variables (except for thigh circumference), serum lipids (except for LDL-cholesterol), and blood pressure. In the pooled material, body mass index (BMI) as well as waist circumference, waist/hip ratio and waist/thigh ratio and subscapular skinfold were positively correlated to serum triglycerides, total cholesterol, LDL-cholesterol, and blood pressure and negatively with HDL-cholesterol. After adjustment for BMI, waist, waist/hip, and waist/thigh were all still significantly correlated with serum triglycerides (P less than 0.001). In addition, waist/hip and waist/thigh ratio showed significant partial correlations with total cholesterol (r = 0.16, P less than 0.001, r = 0.10, P less than 0.05 respectively), and diastolic blood pressure (r = 0.10, P less than 0.05, r = 0.09, P less than 0.05 respectively). In addition, waist/hip was, independently of BMI, correlated to LDL-cholesterol (r = 0.12, P less than 0.01), and waist/thigh ratio with HDL-cholesterol (r = -0.12, P less than 0.01). The partial association between waist/thigh with HDL cholesterol became insignificant after adjustment for smoking habits and physical activity. Adjustment for differences in anthropometric measurements did not explain the differences in serum lipids and blood pressure between the centers. The authors conclude that indicators of body fat distribution are associated with unfavorable risk profiles for cardiovascular disease in European men covering a large geographical and cultural variety and a wide range of body measurements and cardiovascular risk factors.     

Do anthropometric indices accurately reflect directly measured body composition in men and women with chronic heart failure?

How well anthropometric indices such as body mass index (BMI), waist circumference, waist-stature ratio, and waist index correlate with direct measures of body composition (lean body mass, body fat) in men and women with chronic heart failure (CHF) has not been reported. Body composition was assessed by dual-energy x-ray absorptiometry in 140 patients with CHF. Age-adjusted Pearson correlations between each index and measures of body composition for men and women were calculated. Diagnostic accuracy of detecting obesity or high central fat was also examined. In men, all of the anthropometric indices except waist index were just as strongly correlated with lean body mass (correlation coefficients varied between 0.56 for waist-stature ratio to 0.74 for BMI) as with percentage of body fat (correlation coefficients varied between 0.72 for BMI to 0.79 for waist circumference). In women, all 4 anthropometric measures were unable to significantly differentiate between body fat and lean body mass. The positive likelihood ratios for the detection of obesity varied between 2.26 for waist circumference and 3.42 for BMI, waist-stature ratio, and waist index. Anthropometric indices do not accurately reflect body composition in patients with CHF, especially in women. When accurate assessment of body composition is required, direct measurements should be obtained.     

Can anthropometric measures be used as proxies for body composition and physical function in geriatric outpatients?

ObjectivesThe study aimed to evaluate the associations between anthropometric measures with body composition, in particular skeletal muscle mass, and with physical function in a cohort of geriatric outpatients.MethodsWe included 572 outpatients who attended geriatric clinics at Amsterdam UMC, location VUmc, Netherlands from January 2014 to December 2015. Anthropometric measures (height, weight, body circumferences, body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR)), and physical function measures (handgrip strength (HGS), Short Physical Performance Battery (SPPB) and Timed Up and Go test (TUG)) were obtained. Body composition was analysed using bioimpedance analysis (BIA) in a subgroup of 78 patients. Gender-stratified regression analyses were performed to test associations between anthropometric measures with body composition and physical function, adjusted for age.ResultsIn females, BMI, WHtR and all measured body circumferences were positively associated with body fat mass (BFM) (all β≥0.64, all p≤0.001). BMI and mid-upper arm circumference were also associated with fat-free mass (FFM) (β=0.49, p=0.001; β=0.53, p=0.01), skeletal muscle mass (SMM) (β=0.39, p=0.01; β=0.44, p=0.02) and skeletal muscle index (SMI) (β=0.44, p=0.003; β=0.44, p=0.02). In males, BMI, WHR, WHtR and waist circumference were positively associated with BFM (all β≥0.54, all p≤0.02). Calf circumference was associated with FFM (β=0.46, p=0.01), SMM (β=0.47, p=0.01) and SMI (β=0.50, p=0.01). BMI and central fat anthropometric measures were inversely associated with physical function.ConclusionsMid-upper arm circumference and calf circumference could serve as practical proxy measures for skeletal muscle mass in geriatric outpatient setting, but their associations with physical function were weak.     

Leptin concentrations in relation to overall adiposity, fat distribution, and blood pressure in a rural Chinese population

OBJECTIVE: To examine the associations between leptin levels and body mass index (BMI), fat distribution (reflected by waist to hip ratio and skinfold measurements), and blood pressure in a rural Chinese population. DESIGN AND SUBJECTS: A cross-sectional study of 294 participants who provided blood samples. MEASUREMENTS: Plasma concentrations of leptin, BMI, waist to hip ratio, skinfold thickness, and blood pressure. RESULTS: The average leptin concentration was 5.2 microg/l (3.1 for men and 7.3 for women). In univariate analyses, leptin levels were significantly correlated with BMI (r=0.47), abdominal skinfold thickness (r=0.53), triceps skinfold thickness (r=0.56), waist circumference (r=0.41), hip circumference (r=0.51), waist to hip ratio (r=0.17), and diastolic blood pressure (r=0.13). In multivariate analyses controlling for age, sex, education, current smoking, and alcohol use, independent associations between leptin levels and BMI, waist to hip ratio, waist circumference, and abdominal skinfold thickness remained. However, the significant association between leptin and blood pressure disappeared after adjusting for BMI, whereas the association between BMI and blood pressure persisted after adjusting for leptin level. CONCLUSIONS: We observed a strong positive relationship between overall adiposity and leptin levels in both men and women in a rural Chinese population. In addition, leptin concentrations were significantly associated with central obesity measured by waist to hip ratio and abdominal skinfold, independent of overall obesity. The observed positive association between leptin and blood pressure was largely explained by BMI. International Journal of Obesity (2001) 25, 121-125     

Body size and composition in Polynesians

OBJECTIVES: To compare the relationship between body size and body composition in New Zealanders of Polynesian and European descent and to develop specific regression equations for fat mass for Polynesians. SUBJECTS: 189 Maori (93 males, 96 females), 185 Samoans (88 males, 97 females) and 241 Europeans (89 males, 152 females) aged 20-70 y. MEASUREMENTS: Height, weight, four skinfold thicknesses, bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA). RESULTS: At higher body mass index levels, Polynesians (Maori and Samoans combined) had a significantly higher ratio of lean mass:fat mass compared with Europeans. Four multiple regression equations incorporating resistance and reactance, height and weight, sum of four skinfolds or sum of two skinfolds were developed in two-thirds of the Polynesian participants using DXA fat mass as the dependent variable. In the remaining one-third of participants, the mean difference between fat mass predicted by these equations (r2 range 0.89-0.93) and DXA fat mass ranged from -0. 06 to +0.25 kg (s.d. -3.67 to +3.71 kg). CONCLUSION: At higher BMI levels, Polynesians were significantly leaner than Europeans, implying the need for separate BMI definitions of overweight and obesity for Polynesians. The regression equations using BIA, height and weight or skinfold thicknesses were good predictors of body composition in Polynesians.     

Body composition and muscle strength in women scheduled for a knee or hip replacement. A comparative study of two groups of osteoarthritic women

Summary It is unclear whether patients with knee osteoarthritis (OA) and hip OA differ regarding soft tissue composition and bone mineral density (BMD). A total of 42 women waiting for a replacement of the hip (n=20) or the knee (n=22) due to OA were examined. Fat mass (FM), percent body fat (%fat), lean mass (LM) and BMD were measured by dual energy X-ray absorptiometry (DEXA). Knee extensor and flexor strength was measured by an isokinetic dynamometer. No significant differences in age, height, disease duration, Lequesne score or pain scores were found between the groups. Comparing the radiographic changes of the knees with those of the hips, changes were most severe in the joints which were to be replaced. Body weight, body mass index, total and regional FM, and %fat were more than 15% higher in patients waiting for a knee replacement (p<0.001). Also lean mass tended to be higher in the knee patients. Differences in BMD did not remain statistically significant after correction for body weight. Muscle strength was similar in the two groups but was reduced by 20% in the legs in which the joint was to be replaced compared to the contralateral legs. However, the mean difference in lean mass between the two legs was only 3% (p<0.05). The scores for pain felt during strength testing were significantly higher for the involved legs than for the contralateral legs. In conclusion, fat mass values were considerably higher in patients scheduled for a knee replacement. Impaired strength performance in OA may be more strongly associated with pain than with reduced muscle mass.     

Associations of leptin with body fat distribution and metabolic parameters in non-insulin-dependent diabetic patients: no effect of apolipoprotein E polymorphism

Leptin levels have been shown previously to be associated with anthropometric parameters such as the body mass index (BMI), total body fat, and subcutaneous fat. Since apolipoprotein E (apoE) polymorphism is known to be a genetic marker affecting the relationship between certain anthropometric and metabolic parameters, we evaluated whether the leptin level and/or associations between the leptin level and body composition in non-insulin-dependent diabetic patients could be determined by apoE polymorphism. In 171 type 2 diabetic patients (105 male and 66 female), body composition (BMI, waist to hip ratio [WHR], fat mass, and visceral fat) was measured and fasting blood samples were obtained to determine the apoE genotype, leptin, glucose, and insulin levels, and the lipid profile. The mean leptin level for the whole group was 11.7 +/- 9.3 ng/mL, with a significant difference (P < .001) between men (7.1 +/- 4.9 ng/mL) and women (19.0 +/- 10.1 ng/mL). No difference was found for leptin levels or anthropometric variables between the 3 different apoE genotypes (E3/E3 homozygotes, E2 carriers, and E4 carriers). Only low-density lipoprotein (LDL) cholesterol was significantly different between the 3 apoE subgroups. The correlations of leptin with anthropometric variables, especially visceral fat, tended to be different between the 3 apoE groups, but this was not independent and no effect was found after controlling for the other parameters in the model. A multiple regression model containing gender, subcutaneous fat, fasting glucose, triglycerides, and high-density lipoprotein (HDL) cholesterol explained 81% of the variance in leptin levels. We conclude that apoE polymorphism has no effect on the leptin level or its associations with other anthropometric and metabolic parameters.     

人体测量指标与血脂、血糖及血压水平的典型相关

目的：探讨人体测量指标与心血管危险因素水平的相互关系，确定与心血管危险因素相关最密切的人体测量指标。方法：在江苏省金坛县农村抽取３５～５９岁自然人群（男４９２名；女６０６名），测量身高、体重、腰围、腹围、臀围和血胆固醇、高密度脂蛋白胆固醇、血糖、收缩压、舒张压，计算出体重指数（ＢＭＩ）、腰／臀比（ＷＨＲ）、腹／臀比（ＡＨＲ）和锥削度指数（ＣＩ）后，与血脂、血糖及血压水平作典型相关分析。结果：人体测量指标与心血管危险因素指标呈典型相关（典型相关系数为０．３１～０．５０）；人体测量指标中，体重指数的贡献最大，与心血管危险因素的相关最密切；血压是心血管危险因素中与人体测量相关最密切的指标。结论：体重指数是本组人群中最简单但最有价值的人体测量指标；而血压是受肥胖影响最大的心血管危险因素指标。     

New cutoff values for fat mass index,fat-free mass index and percent body fat in overweight and obese men living in Riyadh,SA

The frequent clinical use of bioelectrical impedance analysis (BIA) devices has made clinical evaluations of BIA-based parameters mandatory. This study was performed to define new cutoff points for the fat mass index, fat-free mass index, and percent body fat for overweight and obese men living in Riyadh, KSA. Three hundred sixty-two male subjects aged 18 to 62 years were enrolled in this cross-sectional study. The participants were divided into two groups; one group was assessed with an InBody 720 (n?=?179) device, and the other group was assessed with a Tanita BC-418 (n?=?183) device. Fat mass, fat mass index (FMI), fat-free mass, fat-free mass index (FFMI), and percent body fat (PBF) were measured. In addition, anthropometric measures, including weight, height, body mass index (BMI), waist circumference, hip circumference, waist hip ratio, and mid-arm circumference were included. Pearson correlation coefficients, Kappa analyses, and ROC curves were used. FMI exhibited the strongest positive correlation with BMI among all of the measured BIA-based parameters in both the InBody and Tanita groups (r?=?0.916 and 0.958, respectively, P?<?0.00001). ROC curves indicated that FMI was the most accurate parameter for the diagnosis of obesity in both groups (AUCs?=?0.970 and 0.980). The FMI, FFMI, and PBF cutoff values with the best sensitivities and specificities in both groups were 7.8 vs. 6.7 kg/m², 19.2 vs. 20.7 kg/m², and 27.8 vs. 24 %, respectively, based on the WHO criteria for the diagnosis of obesity in Asian population. FMI was the best predictor of obesity among all of the BIA-based parameters. Considerable differences were noted between the different machines. Knowledge of device-specific cutoff points would increase the clinical value of BIA in the diagnosis of obesity.     

Impact of body mass index on the predictive ability of body fat distribution for Type 2 diabetes risk in Koreans

Aims The optimal anthropometric measure of obesity or body fat distribution that best predicts the risk of Type 2 diabetes in Asians is unclear. Moreover, it has not been determined whether BMI modifies the effect of body fat distribution on diabetes risk in Asians. Methods We analysed the anthropometric and laboratory data of 7658 non‐diabetic Korean adults (5061 men and 2597 women, aged 20–79 years) who underwent routine medical check‐ups at 5‐year intervals. BMI, waist circumference, waist‐to‐height ratio, and bioelectrical impedance (to calculate fat mass and per cent body fat) were measured at baseline. Results Of the 7658 participants, 278 subjects (3.6%) developed diabetes over 5 years. Each of the anthropometric measures of general obesity (BMI, fat mass, per cent body fat) and central body fat distribution (waist circumference and waist‐to‐height ratio) was a good predictor of Type 2 diabetes. However, when the areas under the receiver‐operating characteristic curves were compared, BMI (0.697; 95% CI, 0.669–0.725), waist circumference (0.709, 0.682–0.736) and waist‐to‐height ratio (0.718, 0.692–0.743) were better predictors of diabetes risk than fat mass (0.672, 0.643–0.700) or per cent body fat (0.657, 0.628–0.686). In the low‐ (< 23 kg/m²) and mid‐ (23–27 kg/m²) BMI groups, the addition of waist‐to‐height ratio or waist circumference to BMI could improve the prediction of diabetes risk. Conclusions BMI, waist circumference and waist‐to‐height ratio were good predictors of Type 2 diabetes risk in Koreans. In non‐obese or less obese subjects, measures of central body fat distribution can help improve the prediction of Type 2 diabetes risk when added to measures of general obesity.     

Studies in the distribution of body fat: I. Effects of age, sex, and obesity

The pattern of body fat distribution has been shown to be related to a large number of variables of clinical importance. A variety of indices have been devised, many of them simple enough to be useful in large-scale clinical studies. Relationships among these several indices and systematic information on the effects of age, sex, and obesity have, however, not been systematically studied. Five anthropometric ratios that classify individuals into different body types have been computed for 1179 men and women aged 17-96 years. These are: waist hip ratio, arm thigh ratio, waist thigh ratio, waist arm ratio, and subscapular triceps skinfold ratio. In general, the age patterns show progressive trends toward increasing upper and central body fat deposition with age. In women there tends to be a postmenopausal acceleration of this trend. The ratios are distinctly higher in men than in women and are also independently influenced by the body mass index. Predictive equations that take age and BMI into account for each of the indices for men and women have been provided.