Relation between body composition and age in healthy Japanese subjects

Blood-pool SUV analysis of 99mTc-galactosyl human serum albumin (99mTc-GSA) normalized by blood volume for prediction of short-term survival in severe liver failure: preliminary report

PURPOSE

This study evaluated the usefulness of SUV analysis of 99mTc-galactosyl human serum albumin (99mTc-GSA) scintigraphy including SUV analysis of the cardiac blood pool normalized by blood volume as a predictor of short-term survival in severe liver failure.

PATIENTS AND METHODS

We enrolled 24 patients with severe liver failure who underwent 99mTc-GSA scintigraphy and were admitted to the intensive care unit. Patients were divided into survival and non-survival groups at 7, 14, and 28 days from the performance of 99mTc-GSA scintigraphy. From SPECT images we calculated SUVs of the cardiac blood pool, performing normalization for body weight, lean body weight, Japanese lean body weight, and blood volume and we calculated SUVs of the liver, normalizing by body weight, lean body weight, and Japanese lean body weight. We also calculated the uptake ratio of the heart at 15 min to that at 3 min (HH15) and the uptake ratio of the liver at 15 min to the liver plus the heart at 15 min (LHL15) from planar images of 99mTc-GSA scintigraphy.

RESULTS

There were significant differences between the 7 day survival and non-survival groups for all SUVs of the heart and the liver and HH15, for 14 day survival groups in SUVs of the heart normalized by Japanese lean body weight and blood volume, and no significant differences between 28 day survival groups for any SUVs, HH15, or LHL15. Although the difference was not significant, SUV analysis of the heart normalized by blood volume showed the highest value for the area under the receiver-operating-characteristics curve for both 7 day and 14 day survival.

CONCLUSION

SUV analysis of 99mTc-GSA including SUV analysis of cardiac blood pool normalized by blood volume is of value for prediction of short-term survival in cases with severe liver failure.

Age-appropriate BMI cut-offs for malnutrition among older adults in India

With the increasing prevalence of obesity in India, body mass index (BMI) has garnered importance as a disease predictor. The current World Health Organization (WHO) body mass index (BMI) cut-offs may not accurately portray these health risks in older adults aged 60 years and above. This study aims to define age-appropriate cut-offs for older adults (60-74 years and 75 years and above) and compare the performance of these cut-offs with the WHO BMI cut-offs using cardio-metabolic conditions as outcomes. Using baseline data from the Longitudinal Ageing Study in India (LASI), classification and regression tree (CART) cross-sectional analysis was conducted to obtain age-appropriate BMI cut-offs based on cardio-metabolic conditions as outcomes. Logistic regression models were estimated to compare the association of the two sets of cut-offs with cardio-metabolic outcomes. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity were estimated. Agreement with waist circumference, an alternate measure of adiposity, was conducted. For older adults aged 60-74 years and 75 years and above, the cut-off for underweight reduced from < 18.5 to < 17.4 and < 13.3 respectively. The thresholds for overweight and obese increased for older adults aged 60-74 years old from >  = 25 to > 28.8 and >  = 30 to > 33.7 respectively. For older adults aged 75 years and above, the thresholds decreased for both categories. The largest improvement in AUC was observed in older adults aged 75 years and above. The newly derived cut-offs also demonstrated higher sensitivity and specificity among all age-sex stratifications. There is a need to adopt greater rigidity in defining overweight/obesity among older adults aged 75 years and above, as opposed to older adults aged 60-74 years old among whom the thresholds need to be less conservative. Further stratification in the low risk category could also improve BMI classification among older adults. These age-specific thresholds may act as improved alternatives of the current WHO BMI thresholds and improve classification among older adults in India.

Association of fat-to-muscle mass ratio with physical activity and dietary protein, carbohydrate, sodium, and fiber intake in a cross-sectional study

Higher fat-to-muscle mass ratio (FMR) is reported to be a risk factor for various diseases, including type 2 diabetes and cardiovascular diseases, and mortality. Although this association suggests that reducing FMR may help to prevent certain diseases and mortality, the relationship between FMR and lifestyle factors is unclear. Therefore, we performed a cross-sectional study with the aim to elucidate this relationship. This cross-sectional study included 1518 healthy Japanese adults aged 30 to 64 years. We measured FMR in the whole body, arms, legs, and trunk and assessed various lifestyle factors. Then, we performed forced entry multiple regression analyses for FMR with the following variables: sex, age, physical activity, dietary intake, sleep quality, cigarette smoking, stress levels, and body mass index. As a result, whole-body and regional FMRs were correlated with female sex (β = 0.71); age (β = 0.06); physical activity (β = - 0.07); dietary intake of protein (β = - 0.12), carbohydrate (β = 0.04), sodium (β = 0.13), and fiber (β = - 0.16); and body mass index (β = 0.70). The results suggest that in the Japanese middle-aged population, low FMR is associated with certain lifestyle factors, i.e. higher physical activity and a diet with higher protein and fiber and lower carbohydrate and sodium, independent of age, sex, and body mass index.

Cross-Sectional and Longitudinal Associations between Forearm Bone Mineral Density and Anthropometry in Adult Japanese Men and Women

BACKGROUND

No consensus exists regarding which anthropometric measurements are related to bone mineral density (BMD), and this relationship may vary according to sex and age. A large Japanese cohort was analyzed to provide an understanding of the relationship between BMD and anthropometry while adjusting for known confounding factors.

METHODS

Our cohort included 10,827 participants who underwent multiple medical checkups including distal forearm BMD scans. Participants were stratified into four groups according to age (≥50 years or <50 years) and sex. The BMD values were adjusted for confounding factors, after which single and partial correlation analyses were performed. The prevalence of osteopenia was plotted for each weight index (weight or body mass index [BMI]) class.

RESULTS

Cross-sectional studies revealed that weight was more favorably correlated than BMI in the older group (R=0.278 and 0.212 in men and R=0.304 and 0.220 in women, respectively), whereas weight and BMI were weakly correlated in the younger age groups. The prevalence of osteopenia exhibited a negative linear relationship with weight among older women ≥50 years of age, and an accelerated increase was observed with decreasing weight in older men weighing <50 kg and younger women weighing <60 kg. When weight was replaced with BMI, the prevalence was low in most subgroups classified by weight.

CONCLUSIONS

Weight, rather than BMI, was the most important indicator of osteopenia but it might not be predictive of future bone loss.

The Transcriptomic Landscape of Age-Induced Changes in Human Visceral Fat and the Predicted Omentum-Liver Connectome in Males

Aging causes alterations in body composition. Specifically, visceral fat mass increases with age and is associated with age-related diseases. The pathogenic potential of visceral fat accumulation has been associated with its anatomical location and metabolic activity. Visceral fat may control systemic metabolism by secreting molecules that act in distal tissues, mainly the liver, through the portal vein. Currently, little is known about age-related changes in visceral fat in humans. Aiming to identify molecular and cellular changes occurring with aging in the visceral fat of humans, we analyzed publicly available transcriptomic data of 355 omentum samples from the Genotype-Tissue Expression portal (GTEx) of 20-79-year-old males and females. We identified the functional enrichment of genes associated with aging, inferred age-related changes in visceral fat cellularity by deconvolution analysis, profiled the senescence-associated secretory phenotype of visceral adipose tissue, and predicted the connectivity of the age-induced visceral fat secretome with the liver. We demonstrate that age induces alterations in visceral fat cellularity, synchronous to changes in metabolic pathways and a shift toward a pro-inflammatory secretory phenotype. Furthermore, our approach identified candidates such as ADIPOQ-ADIPOR1/ADIPOR2, FCN2-LPR1, and TF-TFR2 to mediate visceral fat-liver crosstalk in the context of aging. These findings cast light on how alterations in visceral fat with aging contribute to liver dysfunction and age-related disease etiology.

Sex Differences in the Association Between Body Mass Index and Dementia Risk in Community-Dwelling Japanese People Aged 40-74 Years

BACKGROUND

The association between body mass index (BMI) and dementia risk is heterogeneous across age groups and might be influenced by sex.

OBJECTIVE

This study aimed to clarify sex differences in the association between BMI and dementia risk in community-dwelling people.

METHODS

This cohort study with an 8-year follow-up targeted 13,802 participants aged 40-74 years at baseline in 2011-2013. A self-administered questionnaire requested information on body size, including height, weight, and waist circumference (the values of which were validated by direct measurement), socio-demographics, lifestyle, and disease history. BMI was calculated and categorized as < 18.5 (underweight), 18.5-20.6 (low-normal), 20.7-22.6 (mid-normal), 22.7-24.9 (high-normal), 25.0-29.9 (overweight), and≥30.0 kg/m2 (obese). Incident cases of dementia were obtained from the long-term care insurance database. A Cox proportional hazards model was used to calculate multivariable-adjusted hazard ratios (HRs).

RESULTS

The mean age of participants was 59.0 years. In men, higher BMI was associated with lower dementia risk (fully-adjusted p for trend = 0.0086). In women, the association between BMI and dementia risk was U-shaped; the "underweight," "low-normal," and "overweight" groups had a significantly higher risk (fully-adjusted HR = 2.12, 2.08, and 1.78, respectively) than the reference ("high-normal" group). These findings did not change after excluding dementia cases which occurred within the first four years of the follow-up period.

CONCLUSION

Overweight/obese women, but not men, had an increased risk of dementia, suggesting that sex differences in adiposity might be involved in the development of dementia.

Characteristics of total body and appendicular bone mineral content and density in Japanese collegiate Sumo wrestlers

The purpose of this study was to explore the characteristics of total body and appendicular bone mineral content (BMC, kg) and bone mineral density (BMD, g/cm²) in Japanese collegiate Sumo wrestlers. A total of 54 male college Sumo wrestlers were recruited for the study and assigned to two groups according to their body weight (middleweight, 85–115 kg, n = 23 and heavyweight, > 115 kg, n = 31). The BMC, BMD, fat mass, and lean soft tissue mass (LSTM) values were measured using dual-energy X-ray absorptiometry for the total body and appendicular regions. Heavyweight Sumo wrestlers had significantly higher body weight, fat mass, and LSTM compared to middleweight Sumo wrestlers. The mean total body and regional BMC values were significantly higher in heavyweight than in middleweight Sumo wrestlers. The total body and leg BMD was significantly higher in heavyweight than in middleweight Sumo wrestlers, and was significantly correlated with body weight, but not arm BMD. The present study indicates that BMC and BMD might not sharply elevate among even heavyweight athletes, although heavier Sumo wrestlers had a greater BMC and BMD.

Application of a Platform for Gluten-Free Diet Evaluation and Dietary Advice: From Theory to Practice

The present work aimed to analyze, through the GlutenFreeDiet digital platform, the evolution over one year of the nutritional status, dietary profile and symptoms present among celiac people on a gluten-free diet (GFD) while receiving individualized dietary advice. Twenty-seven adults and thirty-one celiac children/adolescents participated in the study. This was then followed up by three visits, at diagnosis, and after 3 and 12 months (vt0, vt3 and vt12). Participants filled out dietary and gastrointestinal symptoms questionnaires. All patients received written personalized dietary advice from dietitians who interpreted data from the platform. Results obtained indicated that participants consumed proteins and lipids in excess and carbohydrates in defect. Low intakes of cereals, fruit and vegetables and high meat intakes were observed. However, gluten-free product (GFP) consumption and that of ultra-processed foods was reduced after 1 year in adults. Symptoms decreased after vt3 but recurred in vt12. Changes in ultra-processed foods and GFP intake, but lack of changes in the rest of the parameters suggested that the platform support was not effective enough. Even though the platform represents a useful tool for monitoring celiac patients and giving dietary advice, modules that require more continuous attention and nutritional education of patients should be provided for interventions to be more effective.

Sex-related differences in the effects of nutritional status and body composition on functional disability in the elderly

Background

The aim of our study was to evaluate the influence of changes of nutritional status and body composition on the results of comprehensive geriatric assessment (CGA) in inpatients of a geriatric ward. Sex differences in these relationships were also investigated.

Methods

A total of 212 elderly patients (>65 years old) admitted to the geriatric ward at the University of Tokyo hospital between 2012 and 2019 were enrolled in this study. CGA (ADL, IADL, MMSE, GDS, Vitality Index) was performed, along with assessment of body compositions (appendicular muscle mass, abdominal muscle mass, body fat mass) and blood malnutrition biomarkers (serum albumin, pre-albumin, 25-hydroxy vitamin D, zinc, hemoglobin concentrations).

Results

Multiple linear regression analysis showed that upper, lower limbs and abdominal muscle masses were significantly associated with the score on ADL in men. On the other hand, abdominal muscle mass was negatively associated with the scores on GDS. Body fat mass was also negatively associated with the score on IADL. In contrast, in women, multiple linear regression analysis failed to show any significant associations between body composition parameters and scores on any domains of CGA. Unlike in men, however, blood malnutrition biomarkers were significantly associated with ADL, IADL, MMSE, and Vitality Index in women.

Conclusions

Our study findings revealed that the association of the nutritional status and body composition with the functional status in the elderly differs by sex. These results suggest that intensification of exercise in men and improvement of the nutritional status in women are particularly useful to maintain the functional status.

Estimation of radiation dose from ingested tritium in humans by administration of deuterium-labelled compounds and food

Radiation doses from organically bound tritium (OBT) in foods have been a major concern near nuclear facilities. The current dose coefficient for OBT is calculated using a standard model from the International Commission on Radiological Protection, in which some biokinetic values are not based on human metabolic data. Here, the biokinetics of ingested OBT, and radiation doses from them, were estimated by administering labelled compounds and foods to volunteers, using a deuterium (D) tracer as a substitute for tritium. After the administration of D-labelled glucose, alanine, palmitic acid, or soybean, the D/H ratios in urine were measured for up to 119 days, and the biokinetic parameter values were determined for OBT metabolism. The slow degradation rates of OBT could not be obtained, in many volunteers administered glucose and alanine. The estimated committed effective dose for 1 Bq of tritium in palmitic acid varied from 3.2 × 10^–11 to 3.5 × 10^–10 Sv Bq⁻¹ among volunteers and, for those administered soybean, it varied from 1.9 × 10^–11 to 1.8 × 10^–10 Sv Bq⁻¹. These results suggest that OBT, present in some ingested ingredients, gives higher doses than the current dose coefficient value of 4.2 × 10^–11 Sv Bq⁻¹.

Sex differences in the prevalence of obesity in 800,000 Chinese adults with type 2 diabetes

AIMS

To estimate the sex differences in the prevalence of overweight and obesity aged 20-89 in Chinese patients with type 2 diabetes (T2D).

METHODS

811,264 patients with T2D from six hospital-based, cross-sectional studies, and 46,053 subjects from the general population were included in our analysis. Prevalence of underweight, overweight, obesity were calculated in each sex.

RESULTS

In patients with T2D, the standardized prevalence of underweight (BMI <18.5 kg/m2), overweight (24 kg/m2 ≤ BMI < 28 kg/m2), and general obesity (BMI ≥28 kg/m2) were 2.2%, 43.2%, and 11.6%, respectively. Similar trend patterns of the prevalence of underweight and overweight were observed in general and T2D population, in males and females with T2D (all P for trend <0.01). In patients with T2D, patients at a younger age and older age were more likely to be underweight. The prevalence of overweight increased first, then stabilized or decreased with age. However, different trend patterns of the prevalence of obesity in males and females were found. In males, the prevalence of obesity decreased first, and then stabilized after 60 years of age. In females, the prevalence of obesity decreased first, then increased after 50 years of age. In the general population, the prevalence of obesity increased with age in females, while, the trend of prevalence of obesity with age in males was not obvious.

CONCLUSION

Different trends in the prevalence of obesity with age in different sex were found in Chinese patients with T2D.

Reference values of body composition parameters for Vietnamese men and women

BACKGROUND

Body composition parameters are linked to cardio-metabolic risk. However, high-quality reference values of body composition are scarce, particularly in Asian population. The aim of study was to construct sex- and age-specific normative reference values of body composition for the Vietnamese population.

METHODS

This study was designed as a cross-sectional investigation that involved 2700 women and 1459 men aged between 20 and 90 (average 48, SD 15) who were participants in the population-based Vietnam Osteoporosis Study. Whole-body composition parameters (e.g., fat mass and lean mass) and site-specific (head, arms, trunk, and legs) parameters were measured by dual-energy X-ray absorptiometry (Hologic Horizon). Reference curves for each parameter and anatomical site were constructed using the Generalized Additive Model for Location Scale and Shape modeling technique.

RESULTS

Overall, 8% of women and 11% of men were classified as obese (body mass index ≥ 27.5 kg/m²). Most fat mass was deposited at the trunk (~50%), followed by the leg (~33%). Women had ~10% more body fat (relative to body weight) than men. However, whole-body lean mass was higher in men than women, with the average difference being ~13 kg. Moreover, men had more bone mineral content than women (2110 vs. 1600 g). We also provided a comparison of age-related changes in body composition parameters between Vietnamese and US Whites.

CONCLUSION

These data provide gender- and age-specific reference values of body composition parameters for Vietnamese population. These normative values provide health professionals and the public with a resource for interpretation of body composition data.

Body mass index and all-cause mortality in older adults: A scoping review of observational studies

In older age, body composition changes as fat mass increases and redistributes. Therefore, the current body mass index (BMI) classification may not accurately reflect risk in older adults (65+). This study aimed to review the evidence on the association between BMI and all-cause mortality in older adults and specifically, the findings regarding overweight and obese BMI. A systematic search of the OVID MEDLINE and Embase databases was conducted between 2013 and September 2018. Observational studies examining the association between BMI and all-cause mortality within a community-dwelling population aged 65+ were included. Seventy-one articles were included. Studies operationalized BMI categorically (n = 60), continuously (n = 8) or as a numerical change/group transition (n = 7). Reduced risk of mortality was observed for the overweight BMI class compared with the normal BMI class (hazard ratios [HR] ranged 0.41-0.96) and for class 1 or 2 obesity in some studies. Among studies examining BMI change, increases in BMI demonstrated lower mortality risks compared with decreases in BMI (HR: 0.83-0.95). Overweight BMI classification or a higher BMI value may be protective with regard to all-cause mortality, relative to normal BMI, in older adults. These findings demonstrate the potential need for age-specific BMI cut-points in older adults.

Multifrequency Bioelectrical Impedance Analysis Compared With Computed Tomography for Assessment of Skeletal Muscle Mass in Primary Colorectal Malignancy: A Predictor of Short-Term Outcome After Surgery

BACKGROUND

Herein, we evaluate the accuracy and reliability of multifrequency bioelectrical impedance analysis (BIA) to assess skeletal muscle mass (SMM) in the colorectal cancer patient compared with computed tomography (CT) scan and also analyze the association between SMM of BIA and postoperative outcomes.

METHODS

From March to May 2017, the body composition of patients scheduled for elective surgery due to primary colorectal cancer in our institution was analyzed at the time of admission using BIA (InBody S20, Biospace Co Ltd, Seoul, South Korea). The relationship between the single cross-sectional area of skeletal muscle at the lumbar region using preoperative CT scan and the SMM determined via BIA were assessed. Postoperative outcomes were compared according to different status of SMM on BIA categorized into 3 groups (low, medium, or high).

RESULTS

Fifty patients were analyzed, and the length of hospital stay was shorter and the initiation of oral diet was significantly earlier in the group with high SMM than in other groups (P = 0.001 and 0.038, respectively). The SMM on BIA showed a very significant correlation with skeletal muscle index using CT scan (0.705 of correlation coefficients, P < 0.001) and also strongly correlated with skeletal muscle index after adjusting for age, weight, and BMI on multivariate analysis (β = 0.391 ± 0.057, P < 0.001).

CONCLUSION

SMM determined by BIA is strongly correlated with SMM estimated by CT scan. Authors suppose that BIA could be an alternative to CT scan for the assessment of SMM in colorectal cancer patients.

Relationship between plasma protein S levels and apolipoprotein C-II in Japanese middle-aged obese women and young nonobese women

: Protein S, a nonenzymatic cofactor to activated protein C, presents in two forms in plasma, free form and in a complex with C4b-binding protein. The aim of this study was to determine the association of plasma protein S levels with the variables related to cardiovascular disease risk. The relationships between plasma protein S levels with lipids, inflammation markers, and adiposity were first examined on middle-aged obese women (n = 62), then on young nonobese women (n = 160) to verify the findings in the obese women. Total and free protein S antigen levels in middle-aged obese women, approximately half being in a postmenopausal state and suffered from dyslipidemia, correlated negatively with estradiol and positively with triglycerides, total cholesterol, LDL cholesterol, apoA-II, apoB, apoC-II, apoC-III, apoE, hemoglobin A1c, and protein C, whereas there was no correlation with HDL cholesterol, apoA-I, BMI, visceral fat area, blood pressure, or factor VII activity. Multiple linear regression analyses revealed that protein C, apoC-II, and fibrinogen were significant predictors of total protein S antigen levels, accounting for 51.9% of variance, and apoC-II as a singular significant predictor for free protein S antigen levels (12.3% of variance). In young nonobese women, most being normolipidemic, apoC-II was also selected as a significant predictor of total protein S antigen levels, but not of free protein S antigen levels. The positive relationship between plasma protein S levels and apoC-II, a key regulator of triglycerides hydrolysis, may contribute to the pathogenesis of increased concentrations of plasma protein S.

Usefulness of standardized uptake value normalized by individual CT-based lean body mass in application of PET response criteria in solid tumors (PERCIST)

Our aim in this study was to verify the usefulness of the standardized uptake value (SUV) normalized by individual CT-based lean body mass (LBMCT) in application of PET response criteria in solid tumors (PERCIST).We retrospectively investigated 14 patients (4 male and 10 female) with malignant lymphoma who were undergoing chemotherapy. (18)F-FDG PET/CT examinations were performed before and after chemotherapy. The LBMCT was calculated by estimation of fat weight from CT data (from skull base to pelvis). The mean ± standard deviation (SD) and the Bland-Altman plot were used for comparison among body weight, LBMCT, and LBM derived from a predictive equation (LBMPE). Indices for FDG uptake in the liver were: SUV, SUV based on LBMPE (SULPE), and SUV based on LBMCT (SULCT). Overall differences between the uptake values were analyzed by one-way ANOVA. If the ANOVA showed significance, differences between uptake values were investigated further by use of the Tukey-Kramer test. The mean values of body weight, LBMPE, and LBMCT were: 55.4 ± 14.9 (39.0-112.0), 43.0 ± 10.5 (31.3-75.2), and 35.3 ± 9.8 (23.4-75.8) kg, respectively. There was a wide dispersion between LBMPE and LBMCT (differences, 7.6 ± 3.6 kg; 95 % CI, 6.42-8.85). LBMPE was higher than LBMCT in all the cases except in Case 11. The mean uptake values significantly differed among SUV, SULPE, and SULCT (F = 68.3, p < 0.05). Whereas SULPE deviated from PERCIST criteria in seven patients, SULCT satisfied the criteria except in one case. These results suggest that liver SULCT is useful for application of PERCIST.

Trend of Body Compositions with Aging among Chinese Adolescents, Adults and Elders

INTRODUCTION

Rare reports can be found about sex- and age-specific body composition survey among Chinese population. The aim of this study is to explore the change of sex-specific body compositions with aging among Chinese adolescents, adults and elders.

METHODS

In a large-scale population survey about physiological constants and health conditions, 75,714 subjects who aged from 8 to 80 completed body composition array. Body mass index (BMI), percentage body fat (PBF), water percentage of body weight (WPBW), water percentage of lean body mass (WPLBM), fat-free mass index (FFMI) and basic metabolic rate were examined with Biodynamics BI-310 body composition analyzer. General obesity is defined as BMI equal to or greater than 28 kg/m2.

RESULTS

The prevalence rates of general obesity were 9.4% for males and 7.7% for females respectively. With aging, PBF and FMI showed a U-shape curvilinear trend and WPBW showed a parabolic trend for males. At same age group: 18-19 age groups, PBF and FMI declined to the valley and WPBW rose to the peak. For females, PBF, WPBW and FMI changed in a linear trend. The values of WPLBM and FFMI showed same curvilinear trend for two genders. WPLBM changed in a U-shape trend and touched the valley in twenties for males and in 18-19 age groups for females. The value of FFMI was larger for older age groups in the younger generation but smaller in the older generation. A parabolic trend peaking was seen in the thirties for males and in the forties for females. Regression models with age as independent variable showed that the larger rate of increase of PBF and smaller rates of increase for WPBM and WPLBM with aging for males.

CONCLUSION

This study presents detailed data about sex-specific body composition conditions. Different change trend with aging was found about body composition conditions.

Bioimpedance Analysis as a Method to Evaluate the Proportion of Fatty and Muscle Tissues in Progressive Myopathy in Pompe Disease

During progressive myopathy, the space of atrophic muscle tissue is gradually filled by fatty tissue. The proportion of these two tissue types relative to body mass provides an indication of the extent of muscle tissue destruction, i.e., the progression and severity of the disease.In this study we use Pompe disease as an example to report the new possibility of using bioimpedance analysis (BIA) to assess the relative proportion of fatty and muscle tissue in diseases associated with muscle atrophy, thus enabling the assessment of disease progression and the effectiveness of treatment. Results from BIA analysis were compared with magnetic resonance images.The results of muscle magnetic resonance images and BIA analysis were similar, which suggests that BIA may provide valuable diagnostic guidance for the assessment of the progression of the disorder.

Reference Values and Age Differences in Body Composition of Community-Dwelling Older Japanese Men and Women: A Pooled Analysis of Four Cohort Studies

Objectives

To determine age- and sex-specific body composition reference values and investigate age differences in these parameters for community-dwelling older Japanese men and women, using direct segmental multi-frequency bioelectrical impedance analysis.

Methods

We conducted a pooled analysis of data collected in four cohort studies between 2008 and 2012: Kusatsu Longitudinal Study, Hatoyama Cohort Study, Itabashi Cohort Study, and Kashiwa Cohort Study. The pooled analysis included cross-sectional data from 4478 nondisabled, community-dwelling adults aged 65-94 years (2145 men, 2333 women; mean age: 72.9 years in men and 72.6 years in women). Body weight, fat mass (FM), percentage FM, fat-free mass (FFM), and appendicular lean soft tissue mass were measured using the InBody 720 and 430 (Biospace Co. Ltd, Seoul, Korea). The values were then normalized by height in meters squared to determine body mass index (BMI), FM index (FMI), FFM index (FFMI), and skeletal muscle mass index (SMI).

Results

Simple means (standard deviation) of BMI, percentage FM, FMI, FFMI, and SMI were 23.4 (2.9) kg/m², 24.9 (6.3)%, 5.96 (2.09) kg/m², 17.4 (1.5) kg/m², and 7.29 (0.76) kg/m², respectively, in men and 22.7 (3.3) kg/m², 31.7 (7.1)%, 7.40 (2.61) kg/m², 15.3 (1.2) kg/m², and 5.86 (0.67) kg/m², respectively, in women. We then calculated quartiles and quintiles for these indices after stratifying for sex and 5-year age group. FFMI and SMI decreased significantly with age in both sexes (P < 0.001 for trends), but FFMI remained constant among the women with only a 1% decrease up to age 84 years. Percentage FM increased significantly, with age (P < 0.001 in men and P = 0.045 in women for trends), but FMI was unchanged in both sexes (P = 0.147 in men and P = 0.176 in women for trends).

Conclusion

The present data should be useful in the clinical evaluation of body composition of older Japanese and for international comparisons. The small age-related decrease in FFMI may be a noteworthy characteristic of body composition change in older Japanese women.

Influence of age and gender on fat mass, fat-free mass and skeletal muscle mass among Australian adults: the Australian diabetes, obesity and lifestyle study (AusDiab)

BACKGROUND

Bioelectrical impedance (BIA) represents a simple, inexpensive and non-invasive method that is often used to assess fat-mass (FM) and fat-free mass (FFM) in large population-based cohorts.

OBJECTIVE

The aim of this study was to describe the reference ranges and examine the influence of age and gender on FM, FFM and skeletal muscle mass (SMM) as well as height-adjusted estimates of FM [fat mass index (FMI)], FFM [fat-free mass index (FFMI)] and SMM [SMM index (SMI)] in a national, population-based cohort of Australian adults.

DESIGN AND PARTICIPANTS

The analytical sample included a total of 8,582 adults aged 25-91 years of Europid origin with complete data involved in the cross-sectional 1999-2000 Australian, Diabetes, Obesity and Lifestyle (AusDiab) Study.

MEASUREMENTS

Bioelectrical impedance analysis was used to examine components of body composition. Demographic information was derived from a household interview.

RESULTS

For both genders, FFM, SMM and SMI decreased linearly from the age of 25 years, with the exception that in men SMI was not related to age and FFM peaked at age 38 years before declining thereafter. The relative loss from peak values to ≥75 years in FFM (6-8%) and SMM (11-15%) was similar between men and women. For FM and FMI, there was a curvilinear relationship with age in both genders, but peak values were detected 6-7 years later in women with a similar relative loss thereafter. For FFMI there was no change with age in men and a modest increase in women.

CONCLUSION

In Australian adults there is heterogeneity in the age of onset, pattern and magnitude of changes in the different measures of muscle and fat mass derived from BIA, but overall the age-related losses were similar between men and women.

How can waist circumference predict the body composition?

BACKGROUND

Waist circumference (WC) is used as a risk assessment for metabolic syndrome, diabetes, and cardiovascular disease (CVD). WC consists of visceral fat area (VFA), subcutaneous fat area (SFA), muscle, intramuscular fat, viscera, and bone. Each component of the WC may differ between the sexes and generations, even if they have the same WC. However, this has not been measured in an epidemiological study.

METHODS

Between 2004 to 2009, employees and their spouses working at a Japanese company underwent a health examination after more than 12 hours of fasting. We analyzed the data of 11,570 subjects (9,874 men and 1,696 women), aged from 20 to 76 years, who underwent a computed tomography (CT) examination. VFA, SFA, WC, muscle, intramuscular fat, viscera, and bone were measured using a CT scanner. We conducted stratified analyses by generational age, and calculated the Pearson's correlation coefficients between the VFA and WC, BMI, and VFA plus SFA. To establish the equations for converting the WC to the corresponding VFA and VFA plus SFA, linear regression analyses were used to obtain the regression coefficients and intercepts.

RESULTS

As the generations increased in age, the VFA tended to increase. However, the differences in the WC values of each generation did not coincide with the VFA values in men (r = -0.275 and 0.979 for men and women, n = 5 generations), but did correlate with the difference in the sum of the VFA plus SFA for both sexes (r = 0.915 and 0.996 for men and women, n = 5 generations). Older generations had lower WC values when they had the same VFA values as the younger generations.

CONCLUSIONS

The WC value corresponding to a certain VFA value differed significantly by generational age. Thus, revised optimal cutoff values for the WC may be needed for each generation.

Testosterone replacement therapy to improve secondary sexual characteristics and body composition without adverse behavioral problems in adult male patients with Prader-Willi syndrome: an observational study

Prader-Willi syndrome (PWS), a complex genetic disorder, arises from suppressed expression of paternally inherited imprinted genes on chromosome 15q11-q13. Characteristics include short stature, intellectual disability, behavioral problems, hypogonadism, obesity, and reduced bone and muscle mass. Testosterone replacement (TR) remains controversial due to concerns regarding behavioral problems. To evaluate the effects of TR on secondary sexual characteristics, body composition, and behavior in adult males with PWS, 22 male PWS patients over the age of 16 with behavioral scores of less than grade 4 on the Modified Overt Aggression Scale (MOAS) underwent monthly intramuscular TR (125 mg). Pubertal change, body composition and behavior were evaluated before and after 24 months of therapy. Serum testosterone, LH, and FSH did not change. Increased pubic hair was observed in 16 of 22 patients (72.7%). Percent body fat decreased from 47.55 ± 2.06% to 39.75 ± 1.60% (n = 18) (P = 0.018). Bone mineral density increased from 0.8505 ± 0.0426 g/cm(2) to 0.9035 ± 0.0465 g/cm(2) (n = 18) (P = 0.036), and lean body mass increased from 18093.4 ± 863.0 g to 20312.1 ± 1027.2 g (n = 18) (P = 0.009). The MOAS was unchanged, from 4.5 ± 2.0 at the beginning of the study to 3.0 ± 1.7 at the end of study indicating no increase in aggression. No behavioral problems were observed. Based on this pilot study, TR with 125 mg monthly is a potentially safe and useful intervention for adult males with PWS.

Six-year longitudinal changes in body composition of middle-aged and elderly Japanese: age and sex differences in appendicular skeletal muscle mass

AIM

Little is known about longitudinal changes of body composition measured by dual-energy X-ray absorptiometry (DXA) in middle-aged and elderly individuals. We evaluated longitudinal changes of body composition, and age and sex differences in appendicular skeletal muscle mass.

METHODS

Participants were 1454 community-dwelling Japanese men and women aged 40-79 years. Body composition at baseline and 6-year follow up was measured by DXA.

RESULTS

Fat increased significantly in men of all ages, and in women aged in their 40s and 50s. Among men, arm lean tissue mass (LTM) changed by 0.9%, -0.5%, -1.4% and -3.7%, respectively, for the 40s to the 70s, and decreased significantly in the 60s and 70s. Leg LTM in men changed by -0.4%, -1.3%, -1.7% and -3.9%, respectively, and decreased significantly from the 50s to the 70s. Compared with the preceding age groups, significant differences were observed between the 60s and 70s in arm and leg LTM change in men. Among women, arm LTM changed by 0.7%, 0.2%, 1.6% and -1.5%, respectively, which was significant in the 60s and 70s. Leg LTM decreased significantly in all age groups of women by -2.0%, -2.8%, -2.4% and -3.9%, respectively. With respect to sex differences, leg LTM loss rates were significantly higher in women than men at the 40s and 50s.

CONCLUSIONS

Longitudinal data suggest that arm and leg LTM decreased markedly in men in their 70s, and leg LTM had already decreased in women in their 40s.

Sex differences in the impact of diabetes on the risk of geriatric conditions

AIM

To examine whether sex differences exist in the relationship between diabetes and geriatric conditions.

METHODS

This was a cross-sectional analysis of 2629 community-dwelling older adults, drawn from the 2003 wave of the "Survey of Health and Living Status of the Elderly in Taiwan." Selected geriatric conditions included cognitive impairment, depression, falls and urinary incontinence (UI). Diabetes and comorbid conditions (heart disease, hypertension, chronic lung disease, stroke, hip fracture, arthritis, chronic kidney disease and cancer) were assessed using questionnaires.

RESULTS

A greater proportion of older women, compared with men, had cognitive impairment (15.8% vs 7.3%), depression (22.6% vs 10.4%), falls (26.7% vs 16.3%), and UI (20.9% vs 15.1%). After adjustment for basic demographics and comorbid conditions, diabetes was associated with increased risk for cognitive impairment (RR 1.85 [CI 1.12-3.05], P=0.017), depression (RR 2.03 [CI 1.39-2.97], P=0.0003) and falls (RR 1.72 [CI 1.2-2.48], P=0.003), but not UI (RR 1.4 [CI 0.9-2.1], P=0.067) among older women. However, we did not find any associations in men.

CONCLUSIONS

Diabetes was associated with excessive risk for geriatric conditions among older women, but not men. The effect of sex differences on the relationship between diabetes and geriatric conditions requires further exploration.

Age-related changes of body composition and abdominal adipose tissue assessed by bio-electrical impedance analysis and computed tomography

Only scarce information is available on body composition changes with age measured simultaneously by electrical impedance and computed tomography.

AIM

We aimed to describe the age-related changes of the body composition and adipose tissue distribution in Bulgarians.

MATERIAL AND METHODS

This cross-sectional study included 130 participants (mean age 53±9.8 years, range 35-65), divided according to their body mass index (BMI): BMI <25.0 kg/m(2) (18 women, 12 men); BMI 25.0-34.9 kg/m(2) (50 women, 50 men). Body composition was assessed by bioelectrical impedance on a Tanita TBF-215 analyzer (Tanita Corp., Tokyo, Japan). The abdominal fat was measured by computed tomography on a CT/L scanner (GE Medical Systems, USA).

RESULTS

Increasing age was associated with a mean decrease in body weight by 268 g per year in the normal weight subjects and by 390 g in the overweight ones as well as with a fat-free mass decrease of 321 g and of 291 g per year respectively (p<0.001). One year of increasing age was associated with a mean increase of visceral adipose tissue by 2.43 cm(2) in the overweight group and by 2.68 cm(2) in the normal weight subjects and with a decrease of the subcutaneous adipose tissue by 2.30 cm(2) per year in the latter group (p<0.001). The association of fat mass and fat-free mass with age in men and women was best described by quadratic equations (both increased until the age of 45-50 and decreased thereafter).

CONCLUSIONS

Our data showed a significant association between age and decreasing fat-free mass, increasing fat mass and abdominal fat accumulation.

A proposed method for the evaluation of body fat in Japanese adults that predicts obesity

The present study was designed to develop a simple predictive equation for the percent body fat (%BF) in Japanese adults based on variables collected during health examinations. We hypothesized that a benchmark for defining metabolic syndrome and obesity could be based on %BF, which was measured by underwater weighing (UW) as a gold standard for body composition assessment. Thus, we developed a predictive equation for %BF derived from UW that may contribute to the assessment of obesity status, characterized by an excess accumulation of visceral or subcutaneous fat. The subjects were 810 Japanese participants (283 men, 527 women, ages 18-59 years). Anthropometric variables, including height, weight, 7 circumferences, and 8 skinfold thicknesses, were measured. The developed predictive equation was as follows: %BF = 10.558 × sex (1 for men; 2 for women) + 0.069 × age + 0.667 × body mass index + 0.314 × abdominal circumference - 35.881.The coefficient of determination (r(2)) was 0.69. The predicted %BF derived from this equation was highly correlated with UW-measured values and did not show underestimation or overestimation in either sex. These data suggested that this predictive equation for %BF can be used for all Japanese adults and does not require the use of medical equipment and special measurement techniques. By combining the equation for %BF developed in this study with a %BF cutoff value of metabolic syndrome and obesity (>25.0% in men and >30.0% in women), all Japanese adults can easily and conveniently assess obesity status.

Associations between energy demands, physical activity, and body composition in adult humans between 18 and 96 y of age

BACKGROUND

Associations between body composition and the energy expended on basal metabolism and activity are complex and age dependent.

OBJECTIVE

The objective was to examine associations between body composition and daily (DEE), basal (BEE), and activity energy expenditure (AEE) throughout the adult life span.

DESIGN

A cross-sectional study was conducted in 529 adults aged 18-96 y. DEE was measured by using doubly labeled water, BEE by using respirometry, and body composition by isotope dilution. AEE was calculated as DEE - BEE, and physical activity level (PAL) was calculated as DEE/BEE.

RESULTS

Up to age 52 y, fat-free mass (FFM) and fat mass (FM) were positively associated with age in men, but no significant effect was observed in women. No effects of age on DEE and AEE were observed. The average DEE in men (14.1 MJ/d) was 27% greater than that in women (10.7 MJ/d). PAL averaged 1.84 in men and 1.75 in women. Above and including the age of 52 y, FFM, FM, DEE, BEE, and AEE were all negatively associated with greater age. The effect of age on AEE was greater than on BEE; consequently, PAL by the age of 95 y was only 1.36. PAL and AEE were both unrelated to FFM (both age adjusted).

CONCLUSIONS

PAL and AEE were not associated with age in subjects aged <52 y. AEE, BEE, and PAL were all negatively associated with age in subjects aged ≥52 y. An absence of a relation between age-adjusted PAL and FFM suggested that greater physical activity was not associated with higher FFM in the elderly.

Changes of muscular load with aging in the motion of pulling up disposable diapers

To elucidate how aging affects the muscular load required for pulling up pants-style disposable diapers, and why some elderly people cannot pull up the rear of their disposable diapers well, we evaluated the electromyogram (EMG) of 8 young subjects (21.5+/-1.5 years) and 7 elderly subjects (71.6+/-6.1 years). EMG was measured for four muscles--biceps brachii, deltoid, brachioradialis, and flexor carpi ulnaris. We evaluated the muscular load during a series of motions for pulling a disposable diaper up at the front and the rear of the body using an EMG-Video Synchronous Split Method. The analysis revealed that the front and the rear integral EMG of elderly subjects were both significantly larger than those of young subjects for all four muscles. For the deltoid and flexor carpi ulnaris muscles, the maximum amplitude of EMG when pulling up the rear of the disposable diapers was significantly larger in the elderly subjects than the young ones. These results suggest that the muscular load involved in pulling up the rear of disposable diapers may increase due to changes in body habitus caused by aging. Since muscular strength decreases with age, it seems likely that the elderly individuals will eventually be unable to pull up the rear of their diapers.

Age-related changes in total and regional fat distribution

Aging is associated with progressive changes in total and regional fat distribution that have negative health consequences. Indeed, a preferential increase in abdominal fat, in particular visceral fat, combined with a decrease in lower body subcutaneous fat are commonly cited in the literature. These age-related changes in body composition can occur independent of changes in total adiposity, body weight or waist circumference, and represent a phenotype closely associated with increased morbidity and mortality risk. Tissues such as the heart, liver and skeletal muscle in the elderly have increased fat deposition, which increases risk for insulin resistance and cardiovascular disease. Furthermore, aging is associated with increased fat content within bone marrow, which exposes the elderly to fracture risk beyond that associated with low bone mineral density alone. Many of the age-associated body compositional changes cannot be detected by simple anthropometric measures alone, and the influence of gender, race or ethnicity, and physical activity patterns on these changes is unclear. This review will explore some of these age-related changes in total and regional fat distribution. Consideration will also be given to the strengths and limitations associated with some of the anthropometric methodologies employed for assessing these changes.

Metabolic syndrome and insulin resistance significantly correlate with body mass index

BACKGROUND

Metabolic syndrome (MetS) is a cluster of metabolic risk factors for cardiovascular disease. This study aimed to compare the prevalence of MetS and its components in different degrees of obesity in Iranian subjects.

METHODS

A total of 2309 adults were divided into four groups according to their body mass index (BMI): 1511 subjects were non-obese (BMI <30 kg/m(2)); 535 were moderately obese (BMI > or =30-<35); 176 were severely obese (BMI > or =35-<40) and 87 were morbidly obese (BMI > or =40). Fasting blood samples were obtained and plasma glucose, lipids, insulin and HbA1c were measured. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. The prevalence of MetS, according to the definitions of the International Diabetes Federation (IDF) and National Cholesterol Education Program Adult Treatment Panel III (ATPIII), was compared across increasing grades of BMI.

RESULTS

Prevalence of MetS gradually rose with increasing grades of obesity (p<0.001), from 31.9% in the non-obese to 69.0% in the morbidly obese according to the IDF criteria and from 31.2% to 62.1% according to the ATPIII criteria. After controlling for age and sex, one grade increase in the BMI category was associated with 2.5-3 times higher risk of MetS depending on the definition used. In addition, HOMA-IR was significantly correlated with BMI in all subjects (r=0.343, p<0.001) and in moderately (r=0.184, p<0.01), severely (r=0.147, p<0.01) and morbidly (r=0.101, p<0.05) obese participants separately.

CONCLUSIONS

MetS and its components, including high blood pressure, central obesity, hyperglycemia, IR, hypertriglyceridemia and low high-density lipoprotein-cholesterol increase in parallel with increasing obesity grades.

Total and regional bone mineral content in healthy Spanish subjects by dual-energy X-ray absorptiometry

DESIGN

This is an observational cross-sectional study.

OBJECTIVE

The aim of the present study was to describe and analyze patterns of change in total and regional bone mineral content in relation to age and gender in a sedentary Spanish sample population (from the Community of Madrid). The age range of the sample population was from birth to 80 years.

MATERIALS AND METHODS

One thousand one hundred twenty healthy subjects were recruited and divided into 16 groups according to age. Each subject underwent whole-body densitometry using dual-energy X-ray absorptiometry. An analysis was made of the amount of bone mineral content (BMC) in the whole body and in different regions: the head, trunk, upper limbs, and lower limbs.

RESULTS

Gender differences in mean values for upper limbs and lower limbs are statistically significant between 16 and 70 years of age. For the head and trunk, the mean BMC values show the most significant gender differences between 16 and 25 years of age (p <or= 0.001). Total bone mineral content (TBMC) and TBMC-to-height ratio show significant gender differences between 16 and 70 years of age. In females, TBMC values increase up to 20 years of age and in males up to 25 years of age.

CONCLUSION

We have determined an evolutionary normal pattern of bone mineral content in urban Spanish people.

Lifestyle factors associated with age-related differences in body composition: the Florey Adelaide Male Aging Study

BACKGROUND

Age-related change in body composition is associated with adverse health outcomes, including functional decline, disability, morbidity, and early mortality. Prevention of age-related changes requires a greater understanding of the associations among age, lifestyle factors, and body composition.

OBJECTIVE

We aimed to comprehensively determine lifestyle factors associated with age-related differences in body composition assessed by using dual-energy X-ray absorptiometry.

DESIGN

We analyzed baseline (cross-sectional) data collected from 2002 to 2005 for approximately 1200 men in the Florey Adelaide Male Aging Study, a regionally representative cohort of Australian men aged 35-81 y.

RESULTS

Mean values for whole-body lean mass (LM) and areal bone mineral density (aBMD) decreased, whereas mean values for abdominal fat mass (FM) and whole-body and abdominal percentage FM (%FM) increased with age. No significant age-related differences were found for whole-body FM. Multiple adjusted odds of being in the highest tertiles for whole-body and abdominal %FM decreased for smokers (63-71%) but increased with age group and for lowest energy (43-50%), carbohydrate (92-107%), and fiber (107%) intake tertiles. Multiple adjusted odds of being in the highest aBMD tertile decreased for lowest body mass (92%) and carbohydrate intake (63%) tertiles and for men aged > or = 75 y (78%) but increased for Australian birth (58%) and for participation in vigorous physical activities (82%).

CONCLUSIONS

Age-related differences in body composition indicate that whole-body FM remains stable but increases viscerally and that whole-body %FM is confounded by LM, whereas aBMD decreases with age. Age-related differences in %FM and aBMD are associated with demographic and lifestyle factors.

Waist circumference is the main determinant of elevated C-reactive protein in metabolic syndrome

BACKGROUND

Metabolic syndrome (MetS) is known to increase the risk of cardiovascular disease. C-reactive protein (CRP) has been reported to be elevated in subjects with MetS. However, which component of MetS contributes mostly to the elevation has not been studied in detail.

METHODS

We studied 628 apparently healthy Japanese subjects (men 262, women 366, age 19-85 years). Body mass index, waist circumference (WC), blood pressure, lipids, glucose, insulin and CRP were measured. MetS was defined according to the National Cholesterol Education Program's Adult Treatment Panel III report.

RESULTS

In partial correlation analysis, WC showed the strongest correlation with CRP among the variables related to MetS. CRP increased as the number of MetS components increased. The mean CRP value adjusted for demographic variables was higher in subjects with MetS than those without MetS, and further adjustments with variables related to MetS revealed that the significant difference between the two groups disappeared only when further adjustment was made for WC. In multiple linear regression analysis, the independent variable that most strongly explained the CRP level was WC, which was followed by HDL-cholesterol. Finally, comparison of the CRP levels in groups stratified by abdominal obesity and the number of MetS components revealed that those with abdominal obesity tended to show higher CRP levels compared with those without abdominal obesity regardless of the number of MetS components other than WC.

CONCLUSIONS

Subjects with MetS showed higher levels of CRP and the main determinant of the CRP elevation was WC.

Evaluating the correlation and prediction of trunk fat mass with five anthropometric indices in Chinese females aged 20-40 years

BACKGROUND AND AIMS

Obesity is a worldwide problem, and excess trunk fat mass (FM(trunk)) has been associated with an increased risk of diseases. The early measurement of FM(trunk) has potential importance to evaluate trunk obesity. We sought to evaluate the correlation and predication of FM(trunk) with five anthropometric indices in Chinese females.

METHODS AND RESULTS

A sample of 850 China females aged 20-40 years were recruited and divided into four age groups with a 5-year range in each group. Five anthropometric indices were measured or calculated. FM(trunk) in kg was measured using a dual-energy X-ray absorptiometry scanner. Principal component analysis (PCA) and multiple regression analysis were performed to develop prediction equations. There was an increasing trend of FM(trunk) and five anthropometric indices in successively older age groups. Four formed principal components (PCs) interpreted over 99% of the total variation of five relative anthropometric indices in all age groups. Regression analyses showed that four PCs combined explained a greater variance (R(2)=45.2-81.6%) in FM(trunk) than did each of the five indices alone (R(2)=2.4-72.2%).

CONCLUSIONS

Our results suggested that there is an increasing trend of FM(trunk) and five anthropometric indices with aging; that age obviously influences the relationship of FM(trunk) and the anthropometric indices studied; and that the accuracy of predicting the FM(trunk) using five anthropometric indices combined is greater than using the five indices alone.

Effect of growth hormone treatment on trunk fat accumulation in adult GH-deficient Japanese patients: a randomised, placebo-controlled trial

OBJECTIVE

Patients with growth hormone deficiency (GHD), both Japanese and Caucasian, have an abnormal body composition with pronounced abdominal obesity. This study aimed to evaluate changes in trunk fat with GH treatment.

DESIGN

Double-blind, placebo-controlled study.

PATIENTS AND MEASUREMENTS

Sixty-one Japanese adult GH deficient patients (mean age 37 years) were randomised to either GH, titrated to 0.012 mg/kg/day, (n = 30) or placebo (n = 31) for 24 weeks. Body composition, by dual-energy X-ray absorptiometry (DXA), was evaluated at a central laboratory for trunk fat, total body fat and lean body mass. Serum lipid levels were also determined centrally.

RESULTS

At baseline, 26 (42.6%) patients had a body mass index (BMI) > or = 25 kg/m(2), the threshold for obesity-related complications for Japanese subjects. Median trunk fat mass (FM) was > or = 9.0 kg for each treatment and gender group, higher than the cut-off for increased age-adjusted risk for cardiovascular complications reported in the normal Japanese population. After 24 weeks of GH treatment, the change in percentage trunk FM was -3.4 +/- 0.6%, versus 0.4 +/- 0.6% with placebo (p < 0.001). Change in total body FM was -2.8 +/- 0.5% with GH and 0.0 +/- 0.5% with placebo, indicating that the decrease in trunk fat was more pronounced than for total body fat. Total and low density lipoprotein (LDL)-cholesterol were both significantly (p < 0.001) decreased compared with placebo. One patient discontinued due to a subdural haematoma and one had GH dose reduced due to hyperglycaemia.

CONCLUSIONS

Japanese patients with GHD have abnormal central fat accumulation, which is reduced by GH treatment over 24 weeks. This may reduce cardiovascular risk but the GH dose should be individualised to maintain IGF-I in the normal range.

Comparison of body composition measurements obtained by two fan-beam DXA instruments

Although dual-energy X-ray absorptiometry (DXA) has been widely used for measuring body composition, discrepancies have been reported to exist among results obtained from different instruments. In the course of longitudinal studies lasting for many years, old instruments may be required to be replaced with new ones, necessitating comparison and validation between the values obtained by the old and new instruments. We compared the data obtained by the two fan-beam DXA instruments, QDR-2000 (Hologic, Waltham, MA) and Delphi (Hologic). Body composition was first measured by the Hologic QDR-2000 and next by the Delphi W within 30 days in 99 healthy subjects. Whole-body fat mass (FM), percentage of FM, arm FM, and leg FM measured by the Hologic QDR-2000 were significantly larger than those measured by the Delphi W. Lean tissue mass (LTM), bone mineral content, and bone mineral density of the whole body, trunk FM, arm LTM, and leg LTM measured by the QDR-2000 were significantly smaller than those measured by the Delphi W. After converting the QDR-2000 values by equations developed by multiple regression analysis, they were not significantly different from the corresponding Delphi values. Measurements by the QDR-2000 and the Delphi W were not interchangeable and the conversion equations reduced the discrepancy to a level that enabled direct comparison of the data obtained by the two instruments. However, cautious interpretation is necessary when the conversion equations are applied to other instruments even of the same type or when evaluating data of individual subjects.

Discordance in the decline in regional lean and bone mass with advancing age

AIM

To investigate whether regional mineral-free lean mass (lean mass) and bone mineral density (BMD) decrease equally with advancing age.

METHODS

Subjects were 420 premenopausal women and 239 postmenopausal women with right-side dominance. Age, height, weight, and body mass index were recorded. Lean mass of the arms, trunk and legs were measured by dual-energy X-ray absorptiometry (DEXA). BMD of the same segmental regions was measured by DEXA.

RESULTS

Trunk and bilateral leg lean mass were inversely correlated to age (r = -0.240, P < 0.0001, -0.167, P < 0.0001, and -0.183, P < 0.0001, respectively), but arm lean mass did not decrease with aging. Regional lean mass was positively correlated to regional BMD (r = 0.284-0.449, P < 0.0001). BMD was inversely correlated to age in all segmental regions (r = -0.586 to -0.449, P < 0.0001).

CONCLUSIONS

Decline in regional lean mass and decline in BMD with advancing age are discordant. Arm lean mass may not contribute to 'age-related decline' in arm BMD, because arm lean mass does not decrease with advancing age in the general population of women.

Do centrally obese Chinese with normal BMI have increased risk of metabolic disorders?

BACKGROUND

Body mass index (BMI) and waist circumference are highly correlated. One or the other predicts the metabolic syndromes better, depending on characteristic of the population studied, such as age, gender, and ethnicity. We examined the impact of isolated central obesity, isolated BMI elevation, and the combined type of obesity on metabolic disorders, in order to shed lights on the strategy of obesity screening.

METHODS

The study subjects were Chinese aged 20 or above residing in Taiwan. Their data were derived from two large-scale studies: the Nutrition and Health Survey in Taiwan (NAHSIT 1993-1996) and the Cardiovascular Disease Risk Factor Two-township Study (CVDFACTS, 1994-1997). In evaluating the relations between obesity and health risks, the cut-points of BMI (> or =24 kg/m(2) for overweight) and waist circumference (> or =80 cm for women and > or =90 cm for men) recommended by Department of Health in Taiwan for Taiwanese people were used to define various types of obesity.

RESULTS

We found that there was a small but nontrivial proportion (1.7% for men and 4.0% for women) of Taiwanese people for whom BMI was in the normal range but their waist circumferences were above normal. These people were at a higher risk of developing metabolic syndromes than those with isolated BMI elevation. Their risks were close to that of the combined type.

CONCLUSIONS

In order to screen out high-risk obese individuals, isolated centrally obese subjects should not be overlooked. Therefore, we recommend to assess waist circumference in parallel to, not just sequential to the measurement of BMI in Chinese.

Favourable association of leg fat with cardiovascular risk factors

OBJECTIVES

To assess the association of trunk and leg fat mass (FM) and leg lean tissue mass (LTM) with conventional cardiovascular risk factors.

DESIGN

Cross-sectional study.

SETTING AND SUBJECTS

We studied 1249 men and 3007 women (age 20-79 years) who attended a research institute for a health checkup between October 1995 and February 2004.

MAIN OUTCOME MEASURES

Body mass index, waist circumference (WC), hip circumference (HC), systolic and diastolic blood pressure, total cholesterol, HDL cholesterol, triglycerides, glucose and haemoglobin A(1C) were measured. Trunk FM, leg FM and leg LTM were obtained by dual-energy X-ray absorptiometry. We evaluated the associations between the indices for regional body composition and cardiovascular risk factors, which included hypertension, hypercholesterolaemia, hypo-HDL cholesterolaemia, hypertriglyceridaemia, dyslipidaemia and diabetes mellitus.

RESULTS

Increase in WC and HC respectively showed increase and decrease in odds ratios of cardiovascular risk factors. Increase in trunk FM by 1 kg significantly increased the risk of the cardiovascular risk factors with the odds ratios ranging between 1.11 and 1.45. Increase in leg FM by 1 kg significantly decreased the risk with the odds ratios ranging between 0.52 and 0.90, except for the nonsignificant results for hypercholesterolaemia and hypo-HDL cholesterolaemia in men. Odds ratios of 1 kg increase in leg LTM were only significant for dyslipidaemia in men and hypercholesterolaemia in women (both 0.93).

CONCLUSIONS

WC and HC showed opposite and independent associations with cardiovascular risk factors. The favourable association of HC was mainly attributable to that of leg FM.

Obesity over the life course

Obesity in middle-aged humans is a risk factor for many age-related diseases and decreases life expectancy by about 7 years, which is roughly comparable to the combined effect of all cardiovascular disease and cancer on life span. The prevalence of obesity increases up until late middle age and decreases thereafter. Mechanisms that lead to increased obesity with age are not yet well understood, but current evidence implicates impairments in hypothalamic function, especially impairments in the ability of hypothalamic pro-opiomelanocortin neurons to sense nutritional signals. The rapid increase in the prevalence of obesity at all ages in the past decade suggests that, in the next two or three decades, diseases associated with obesity, especially diabetes, will begin to rise rapidly. Indeed, these trends suggest that for the first time in modern history, the life expectancy of people in developed societies will begin to decrease, unless the rapid increase in the prevalence of obesity can be reversed.

Sarcopenia and increased adipose tissue infiltration of muscle in elderly African American women

BACKGROUND

Aging is associated with metabolic, physiologic, and functional impairments, in part through age-related changes in body composition. During the later adult years, skeletal muscle mass decreases and body fat becomes centralized.

OBJECTIVE

The goal of the study was to investigate body composition over time ( +/- SD: 2.04 +/- 0.6 y) in healthy, ambulatory, elderly African American women. The hypothesis that a reduction in total-body skeletal muscle (SM) and increases in visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) are ongoing in healthy, weight-stable elderly was tested.

DESIGN

The study was a longitudinal evaluation of 26 women (age at baseline: 75.5 +/- 5.1 y) with a body mass index (in kg/m(2)) of 27.0 +/- 4.0. Body composition was measured by using whole-body magnetic resonance imaging for the quantification of SM, total adipose tissue (TAT), VAT, SAT, and IMAT.

RESULTS

SM (P < 0.001) and bone (P < 0.05) masses decreased, and regional analyses showed a decrease in dual-energy X-ray absorptiometry-derived leg SM (P < 0.05). VAT (P = 0.011) and IMAT (P < 0.001) increased. No changes occurred in TAT (P = 0.45), SAT (P = 0.96), physical function, or food intake.

CONCLUSION

These data show an age-related remodeling of body composition with reductions in SM and corresponding increases in VAT and IMAT. Changes in the previously unstudied depot of IMAT may be involved in the deterioration of metabolic values frequently observed during aging.