Effects of a single dose of rocuronium in patients with different body fat percentages: A randomised controlled trial.

The pharmacodynamics in patients with high body fat percentage might be similar to those in obese patients. This randomised controlled clinical trial observed the effects of rocuronium in patients with different percent body fats (PBFs). Fifty-four patients who underwent elective urological or pelvic surgery under general anaesthesia at Shanghai General Hospital were included in the present study; 51 patients were included for data analysis. Patients with normal PBF (<25%) were given a single dose of rocuronium calculated based on total body weight (N-TBW, control group). Patients with a higher PBF (≥25%) were given a single dose of rocuronium calculated based on total body weight (H-TBW). Patients with higher PBF and rocuronium were dosed based on fat-free mass (H-FFM). A train of four (TOF)-Watch acceleromyography monitor was used to measure the effects of the rocuronium. H-TBW (91.9 ± 28.8 s) had significantly shorter onset time than N-TBW and H-FFM (p = 0.003). H-TBW had significantly longer clinical duration time and pharmacological duration time than the other groups (p = 0.000 and 0.000, respectively); the TOF ratio0.25-0.9 time was significantly different among the three groups (p = 0.005). There were no significant differences in the recovery time (p = 0.103) or recovery index (p = 0.159) among the three groups. The effects of rocuronium dosed based on FFM in patients with high PBFs are similar to those in normal patients. A single dose of rocuronium calculated based on TBW might shorten the onset time, prolong the clinical and pharmacological duration times, and prolong the recovery time.

Associations among motor competence, health-related fitness, and physical activity in children: A comparison of gold standard and field-based measures.

This study compared the associations among motor competence, health-related fitness, and physical activity measured by gold standard and field-based methods in children. A total of 248 first-grade children (153 boys) aged 6-7 years participated in the study. Motor competence was assessed using the Test of Gross Motor Development, Second Edition (TGMD -2). Gold standard measures were percent body fat using dual-energy X-ray absorptiometry, peak oxygen uptake per weight using a gas analyser, and moderate-to-vigorous physical activity using accelerometers. Field-based measures were body mass index, maximum speed during progressive running on a treadmill, and a physical activity questionnaire. Multiple regression analysis adjusted for age and sex was used to examine the associations of motor competence with one of the health-related variables and compared differences by measurement method. The results indicated that field-based measures models showed lower associations (R2 = 0.02-0.17) than the gold standard (R2 = 0.21-0.27) and lower standardised regression coefficients for sex and motor competence, except for maximum speed. In conclusion, gold standard measures resulted in stronger associations between motor competence, and health-related fitness and physical activity in children. Examining the contribution of motor competence in children's health using field-based tests can underestimate it.

Comparison of four quick and reliable methods of assessing body fat appropriate for clinical settings among young, middle-age, and older healthy male and female adults.

[Purpose] Compare four quick (approximately 60 s), reliable methods of assessing %body-fat (%BF) among young (Y, 18-34 years), middle-age (M, 35-59 years), and older (O, 60-88 years) healthy-adults. [Participants and Methods] One-hundred-eighty healthy males-and-females were equally (n=30) divided into Y, M, and O age groups to assess %BF. The %BF methods were: 1) Bioelectrical-impedance-Inbody770 (IB)-criterion reference; 2) Body-mass-index (BMI); 3) Abdominal-and-hip circumferences (CIR); and 4) Skinfold (SF). [Results] %BF were significantly different among the four body-fat methods and among the three age-groups for both males-and-females. %BF among IB,BMI,CIR, and SF were, respectively, 15.7 ± 4.7%, 19.6 ± 3.2%, 17.3 ± 3.5%, and 12.1 ± 4.1% for Y-males; 18.3 ± 5.7%, 22.8 ± 3.6%, 19.6 ± 3.6%, and 15.6 ± 4.5% for M-males; 24.4 ± 6.5%, 25.8 ± 3.3%, 24.0 ± 4.5%, and 20.0 ± 4.1% for O-males; 24.9 ± 6.9%, 28.9 ± 4.1%, 29.4 ± 4.6%, and 22.4 ± 6.3% for Y-females; 25.1 ± 7.0%, 31.4 ± 4.7%, 33.0 ± 4.5%, and 25.0 ± 4.5% for M-females; 35.1 ± 6.3%, 35.5 ± 4.3%, 38.4 ± 4.8%, and 26.4 ± 3.7% for O-females. [Conclusion]The most accurate %BF-methods to use in clinical settings are CIR for Y-and-M-males, CIR and BMI for O-males, SF for Y-and M-females, and BMI for O-females. The least accurate %BF methods are BMI and SF for Y-males, BMI for M-males, SF for O-males, BMI and CIR for Y-and M-females, and SF for O-females. While all 4-methods of assessing %BF can easily and quickly be employed in clinical settings, some methods significantly underestimate or overestimate %BF and yield different results among varying age groups and sex. These findings help identify people at early health risk of cardiometabolic disease, with O-males and O-females at higher risk.

Preoperative percent body fat in bioelectrical impedance analysis predicts pancreatic fistula after pancreaticoduodenectomy.

BACKGROUND: It is unclear which body composition affects postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy. In the present study, we evaluated the relationship between nutritional factors, body composition, and POPF. METHODS: This was a prospective observational cohort study. Patients who underwent pancreaticoduodenectomy between March 2018 and July 2021 were included in this study. Preoperative body composition was measured using a bioelectrical impedance analyzer. In addition, the predictive factors for POPF were analyzed using logistic regression model. RESULTS: The study included 143 patients. Among these patients, 31 had POPF (POPF group) and 112 did not (non-POPF group) after pancreaticoduodenectomy. For body composition, the percent body fat was significantly higher in the POPF group (26.90 vs 23.48, P = 0.022). Multivariate analysis revealed that alcohol consumption (odds ratio 2.95, P = 0.03), pancreatic duct < 3 mm (odds ratio 3.89, P < 0.01), and percent body fat (odds ratio 1.08, P = 0.01) were significantly independent predictive factors for POPF. When the patients were divided into three groups based on their percent body fat (< 25, 25-35, and ≥ 35), POPF occurred more frequently in the group with ≥ 35 percent body fat (47.1%) than in the < 25 group (15.5%) (P = 0.008). CONCLUSION: Predictive factors for POPF related to nutritional status, such as percent body fat, should be considered before proceeding to pancreaticoduodenectomy (ClinicalTrials.gov trial registration no. NCT5257434).

Assessment of body fat mass, anthropometric measurement and cardiometabolic risk in children and adolescents with achondroplasia and hypochondroplasia.

Achondroplasia is a rare skeletal dysplasia characterized by rhizomelic short stature, whose prevalence is about 1 per 25,000 births. For some patients with achondroplasia, excess body weight is one of the major concerns due to an impaired linear growth. Epidemiological studies revealed a premature onset of cardiovascular or cerebrovascular events in achondroplasia. An association between obesity and cardiometabolic risk factors related to cardiovascular events remains unknown in patients with achondroplasia/hypochondroplasia. This cross-sectional study investigated anthropometric measurements, body compositions and cardiometabolic risk factors in pediatric patients with achondroplasia/hypochondroplasia. Thirty-two patients with achondroplasia and ten with hypochondroplasia aged between 1.9 and 18.7 years were enrolled in this study. Half of the participants presented at least one cardiometabolic abnormality. Elevated systolic blood pressure was the most common abnormality. None of the participants developed metabolic syndrome or type 2 diabetes mellitus. Body mass index-standard deviation score and hip/height ratio were strongly correlated with percent body fat assessed by dual energy X-ray absorptiometry although no significant association was found between anthropometric measurements or body fat mass and any cardiometabolic risk factors. No significant difference in body fat mass, as well as body mass index-standard deviation score and hip/height, was found between cardiometabolically normal group and cardiometabolically abnormal groups. These results suggest that not only weight gain and hip/height changes should be monitored but also individual cardiometabolic risk factors should be evaluated to avoid cardiometabolic events in the healthcare management of pediatric patients with achondroplasia/hypochondroplasia.

Relationship of body mass index with frailty and all-cause mortality among middle-aged and older adults.

BACKGROUND: Parallel to growth of aging and obese populations, the prevalence of metabolic diseases is rising. How body mass index (BMI) relates to frailty and mortality across frailty levels is controversial. We examined the associations of high BMI with frailty and mortality and explored the effects of percent body fat on these associations. METHODS: We included 29,937 participants aged ≥50 years from the 2001-2006 National Health and Nutrition Examination Survey (NHANES) cohorts (N=6062; 53.7% females) and from wave 1 (2004) of Survey of Health, Ageing and Retirement in Europe (SHARE) (N=23,875; 54% females). BMI levels were categorized as: normal: 18.5-24.9 kg/m2, overweight: 25.0-29.9, obese grade 1: 30.0-34.9, and obese grade 2 or 3: >35.0. A frailty index (FI) was constructed excluding nutrition-related items: 36 items for NHANES and 57 items for SHARE. We categorized the FI using 0.1-point increments: FI ≤ 0.1 (non-frail), 0.1 < FI ≤ 0.2 (very mildly frail), 0.2 < FI ≤ 0.3 (mildly frail), and FI > 0.3 (moderately/severely frail). Percent body fat was measured using DXA for NHANES participants. All-cause mortality data were obtained until 2015 for NHANES and 2017 for SHARE to estimate 10-year mortality risk. All analyses were adjusted for age, sex, educational, marital, employment, and smoking statuses. RESULTS: Mean age of participants was 63.3±10.2 years for NHANES and 65.0±10.0 years for SHARE. In both cohorts, BMI levels ≥25 kg/m2 were associated with higher frailty, compared to normal BMI. In SHARE, having a BMI level greater than 35 kg/m2 increased mortality risk in participants with FI≤0.1 (HR 1.31, 95%CI 1.02-1.69). Overweight participants with FI scores >0.3 were at lower risk for mortality compared to normal BMI [NHANES (0.79, 0.64-0.96); SHARE (0.71, 0.63-0.80)]. Higher percent body fat was associated with higher frailty. Percent body fat significantly mediated the relationship between BMI levels and frailty but did not mediate the relationship between BMI levels and mortality risk. CONCLUSIONS: Being overweight or obese is associated with higher frailty levels. In this study, we found that being overweight is a protective factor of mortality in moderately/severely frail people and obesity grade 1 may be protective for mortality for people with at least a mild level of frailty. In contrast, obesity grades 2 and 3 may be associated with higher mortality risk in non-frail people. The relationship between BMI and frailty is partially explained by body fat.

Are patterns of family evening meal practices associated with child and parent diet quality and weight-related outcomes?

Family meal practices such as family member presence, fast food consumption and media usage have been associated with health outcomes. However, little is known about combinations of family meal practices and their effects on diet and health. This secondary data analysis aimed to identify patterns of family evening meal practices and examine their associations with family characteristics (e.g., demographics and chaos) and child and parent diet quality and weight-related outcomes. We used baseline data from a community-based randomized controlled trial with 7- to 10-year-old children and their parents in rural Minnesota (n = 114). Parent-reported structural (e.g. media usage) and interpersonal (e.g. mealtime routines) aspects of family evening meal practices were included in latent profile analyses to identify patterns. Diet quality was assessed by child Healthy Eating Index-2015 and parent fruit and vegetable intake. Weight-related outcomes were determined using measured body mass index (z-scores) and percent body fat. A 3-class model was the model of best-fit. The Unplanned Infrequent Family Evening Meals with Mixed Healthfulness class (C1) featured the least frequent family evening meals and the lowest scores for mealtime routines and planning skills. The Family Evening Meals with Fast Food class (C2) characterized having family evening meals four times a week, but fast food was often served. The Planful, Healthful and Frequent Family Evening Meals class (C3) reported the highest meal routine and planning scores as well as frequent family evening meals. Parents in C3 had higher consumption of fruits and vegetables and children in C3 had lower percent body fat, compared to those in other classes. Distinctly different patterns of family evening meal practices suggest a need for considering heterogeneity of family evening meal practices in developing tailored family-meal interventions.

Visceral fat area is the measure of obesity best associated with mobility disability in community dwelling oldest-old Chinese adults.

BACKGROUND: Although obesity can be clinically defined by body mass index (BMI), waist circumference, percent body fat, or visceral fat area, it is unclear which specific measure is best associated with mobility disability in oldest-old adults. METHODS: Among 589 Chinese participants aged 85 years and older in a population-based cohort in Singapore, we measured waist circumference, computed BMI, estimated appendicular skeletal muscle mass, percent body fat, and visceral fat area using bioelectrical impedance analysis, and evaluated mobility disability using the Loco-Check questionnaire. We computed areas under the receiver operating characteristic curves (AUCROC) to compare how well these measures discriminated between those with and without mobility disability. Logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (CI) for the associations between obesity defined by these measures and mobility disability. RESULTS: Compared to BMI, which had an AUCROC (95% CI) of 0.68 (0.64-0.72) for the discrimination of mobility disability, only visceral fat area had a significantly higher discriminative performance [AUCROC (95% CI) of 0.71 (0.67-0.75) (Padjusted = 0.002)]. The optimal cut-offs of visceral fat area for the discrimination of mobility disability were ≥ 104 cm2 in men and ≥ 137 cm2 in women. In fully adjusted models, only obesity defined by visceral fat area was significantly associated with mobility disability [OR (95% CI) of 2.04 (1.10-3.77)]; obesity defined by the other measures were not associated with mobility disability after adjusting for visceral fat. CONCLUSION: In oldest-old adults, visceral fat area was the best discriminator for obesity associated with mobility disability.

High body fat percentage is associated with primary aldosteronism: a cross-sectional study.

BACKGROUND: Excess aldosterone has been shown to be associated with obesity; however, there is currently a lack of data regarding the relationship between percentage of body fat and primary aldosteronism (PA), particularly pertaining to Asian populations. Furthermore, essential hypertension may mimic the condition of PA and there needs to be differentiation between the two. This study aimed to assess the association between percentage of body fat and PA. METHODS: A cross-sectional study was conducted in the outpatient department of the Endocrine and Metabolism Unit of the tertiary care medical center in Thailand. Data was obtained from 79 patients who had been screened for PA due to hypertension in young-onset, hypokalemia, adrenal incidentaloma or resistance hypertension. Essential hypertension was defined as patients who had high blood pressure and were negative for PA screening. Body fat percentage was assessed by bioelectrical impedance analysis. The relationship between percentage of body fat and a diagnosis of PA was assessed using logistic regression analysis, including adjustment for confounding factors. RESULTS: The participants were divided into a PA group (n = 41) and an essential hypertension group (n = 38). After controlling for confounding variables (age, sex, body mass index, cholesterol and insulin resistance status), the odds ratio of having PA in males with a percentage of body fat > 25% and females with percentage > 30% was 1.82 (95%CI = 1.79-1.86, p < 0.001). CONCLUSION: A higher percentage of body fat is associated with an increased risk of PA. Further studies need to be conducted to confirm the relationship between body fat percentage and PA.

Dry Electrode-Based Body Fat Estimation System with Anthropometric Data for Use in a Wearable Device.

The bioelectrical impedance analysis (BIA) method is widely used to predict percent body fat (PBF). However, it requires four to eight electrodes, and it takes a few minutes to accurately obtain the measurement results. In this study, we propose a faster and more accurate method that utilizes a small dry electrode-based wearable device, which predicts whole-body impedance using only upper-body impedance values. Such a small electrode-based device typically needs a long measurement time due to increased parasitic resistance, and its accuracy varies by measurement posture. To minimize these variations, we designed a sensing system that only utilizes contact with the wrist and index fingers. The measurement time was also reduced to five seconds by an effective parameter calibration network. Finally, we implemented a deep neural network-based algorithm to predict the PBF value by the measurement of the upper-body impedance and lower-body anthropometric data as auxiliary input features. The experiments were performed with 163 amateur athletes who exercised regularly. The performance of the proposed system was compared with those of two commercial systems that were designed to measure body composition using either a whole-body or upper-body impedance value. The results showed that the correlation coefficient ( r 2 ) value was improved by about 9%, and the standard error of estimate (SEE) was reduced by 28%.

Adiposity in Adolescents: The Interplay of Sleep Duration and Sleep Variability.

OBJECTIVE: To assess whether adiposity measures differed according to joint categories of sleep duration and sleep variability in a sample of Mexican adolescents. STUDY DESIGN: A sample of 528 Mexico City adolescents aged 9-17 years wore wrist actigraphs for 6-7 days. Average sleep duration was categorized as age-specific sufficient or insufficient. Sleep variability, the standard deviation of sleep duration, was split at the median into stable versus variable. Adiposity measures-body mass index (BMI)-for-age Z score (BMIz), triceps skinfolds, waist circumference, and percent body fat-were collected by trained assistants. We regressed adiposity measures on combined sleep duration and variability categories. Log binomial models were used to estimate prevalence ratios and 95% CI for obesity (>2 BMIz) by joint categories of sleep duration and variability, adjusting for sex, age, and maternal education. RESULTS: Approximately 40% of the adolescents had insufficient sleep and 13% were obese. Relative to sufficient-stable sleepers, adolescents with insufficient-stable sleep had higher adiposity across all 4 measures (eg, adjusted difference in BMIz was 0.68; 95% CI, 0.35-1.00) and higher obesity prevalence (prevalence ratio, 2.54; 95% CI, 1.36-4.75). Insufficient-variable sleepers had slightly higher BMIz than sufficient-stable sleepers (adjusted difference, 0.30; 95% CI, 0.00-0.59). CONCLUSIONS: Adolescents with consistently insufficient sleep could be at greater risk for obesity. The finding that insufficient-variable sleepers had only slightly higher adiposity suggests that opportunities for "catch-up" sleep may be protective.

Use-of-time and health-related quality of life in 10- to 13-year-old children: not all screen time or physical activity minutes are the same.

PURPOSE: To investigate associations between aspects of time use and health-related quality of life (HRQoL) in youth. METHODS: 239 obese and healthy-weight 10- to 13-year-old Australian children completed the Pediatric Quality of Life Inventory (PedsQL™) quantifying their health-related quality of life. Time use was evaluated over four days using the Multimedia Activity Recall for Children and Adolescents (MARCA), a validated 24 h recall tool. The average number of minutes/day spent in physical activity (divided into sport, active transport and play), screen time (divided into television, videogames and computer use), and sleep were calculated. Percent fat was measured using dual-energy X-ray absorptiometry, Tanner stage by self-report, and household income by parental report. Sex-stratified analysis was conducted using Partial Least Squares regression, with percent fat, Tanner stage, household income, and use-of-time as the independent variables, and PedsQL™ total, physical and psychosocial subscale scores as the dependent variables. RESULTS: For boys, the most important predictors of HRQoL were percent fat (negative), videogames (negative), sport (positive), and Tanner stage (negative). For girls, the significant predictors were percent fat (negative), television (negative), sport (positive), active transport (negative), and household income (positive). CONCLUSION: While body fat was the most significant correlate of HRQoL, sport was independently associated with better HRQoL, and television and videogames with poorer HRQoL. Thus, parents and clinicians should be mindful that not all physical activity and screen-based behaviours have equivocal relationships with children's HRQoL. Prospective research is needed to confirm causation and to inform current activity guidelines.

Effects of moderate and vigorous physical activity on fitness and body composition.

Current physical activity (PA) guidelines indicate that moderate-intensity (MPA) and vigorous intensity (VPA) PA provide similar benefits when total volume is equal. The present study examined the associations of MPA and VPA with body composition and cardiorespiratory fitness in free-living young adults. A total of 197 young adults (52.8 % male) were followed over a period of 15 months. Body composition was assessed via dual X-ray absorptiometry and time spent in various PA intensities was determined with a multi-sensor device every 3 months. Cardiorespiratory fitness was assessed with a graded exercise test at baseline and 15-months follow-up. Change in VPA was positively associated with cardiorespiratory fitness while MPA had beneficial associations with percent body fat. In overweight/obese participants the association with VO2peak was similar for MVPA bouts and VPA. Even though MPA and VPA have positive associations with overall health, their associations on key health parameters differ.

Effects of high-intensity interval training on cardiometabolic risk factors in overweight/obese women.

The purpose of this study was to evaluate two practical interval training protocols on cardiorespiratory fitness, lipids and body composition in overweight/obese women. Thirty women (mean ± SD; weight: 88.1 ± 15.9 kg; BMI: 32.0 ± 6.0 kg · m(2)) were randomly assigned to ten 1-min high-intensity intervals (90%VO2 peak, 1 min recovery) or five 2-min high-intensity intervals (80-100% VO2 peak, 1 min recovery) or control. Peak oxygen uptake (VO2 peak), peak power output (PPO), body composition and fasting blood lipids were evaluated before and after 3 weeks of training, completed 3 days per week. Results from ANCOVA analyses demonstrated no significant training group differences for any primary variables (P > 0.05). When training groups were collapsed, 1MIN and 2MIN resulted in a significant increase in PPO (∆18.9 ± 8.5 watts; P = 0.014) and time to exhaustion (∆55.1 ± 16.4 s; P = 0.001); non-significant increase in VO2 peak (∆2.36 ± 1.34 ml · kg(-)(1) · min(-)(1); P = 0.185); and a significant decrease in fat mass (FM) (-∆1.96 ± 0.99 kg; P = 0.011). Short-term interval exercise training may be effective for decreasing FM and improving exercise tolerance in overweight and obese women.

Association of body composition with bone mineral density in northern Chinese men by different criteria for obesity.

UNLABELLED: With impressive economic development, obesity has emerged as a critical public health issue in China. Recently it was reported that obesity has taken an adverse effect on osteoporosis. Because there is different body mass index (BMI) for obesity globally, studies based on BMI levels on association of obesity with osteoporosis were quite few. Therefore, we discussed the relationship of body composition with skeletal BMD according to WHO BMI and BMI on Working Group on Obesity in China (WGOC). METHODS: A total of 502 adult men aged 20-89 were enrolled as healthy subjects for osteoporosis study at Qianfoshan Hospital, Shandong University between September 2008 and August 2010. According to WHO BMI, all subjects were divided into three groups: normal weight (18.5 ≤ BMI < 25 kg/m(2), n = 202), overweight (25 ≤ BMI < 30 kg/m(2), n = 242), and obesity (BMI ≥ 30 kg/m(2), n = 58). According to WGOC BMI, normal weight (18.5 ≤ BMI < 24 kg/m(2), n = 137), overweight (24 ≤ BMI < 28 kg/m(2), n = 225), and obesity (BMI ≥ 28 kg/m(2), n = 140). Total body and regional BMD, lean mass (LM), lean body mass index (LBMI), fat mass (FM), percent body fat (%BF) and fat mass index (FMI) were measured by dual-energy X-ray absorptiometry. Age-partial Pearson correlation analyses between body composition-related parameters and BMD. Multiple regression analyses were performed to explore the associations of BMD with LM, LBMI, FM, %BF and FMI. RESULTS: Fat mass (FM), %BF, FMI, LM and LBMI were positively correlated with BMD at almost sites (P < 0.001) in all subjects. However, the relationship was not different among groups. LM, LBMI, FM and FMI were positively correlated with BMD (P < 0.01) in normal weight. LM and LBMI appeared significantly positive with BMD in overweight and obesity according to WHO and WGOC criteria. %BF and FMI were negative significance with BMD at total body and some regional BMD according to WHO criteria in overweight (P < 0.05). In two obese groups, %BF appeared negatively significant with BMD (P < 0.05) according to WGOC criteria, and %BF and FMI appeared negatively significant with BMD (P < 0.05) according to WHO criteria. In regression of independent variables as FM and LM, LM showed statistically positively significant relations with BMD at almost sites (P < 0.05) in all groups. FM appeared positively significant with BMD in normal groups and overweight group according to WGOC criteria. In regression of independent variables as %BF and FMI, %BF and FMI appeared statistically negatively significant relations with BMD in overweight and obesity, but %BF and FMI were inconsistent in same site. CONCLUSIONS: Lean mass (LM) and LBMI could help to determinant of BMD, and %BF and FMI were adverse to BMD in overweight and obesity. Comparing with two criteria, we found the differences in fat-related parameters and BMD according to WHO criteria were more obvious than that according to WGOC criteria. We also found that %BF and FMI were useful to research the relationship between osteoporosis and obesity at the same time.

Cortisol reactivity, delay discounting and percent body fat in Chinese urban young adolescents.

The purpose of this study is to test the relation of cortisol reactivity, delay discounting and percent body fat (PBF) in adolescents aged 12-13 years (N=87), and evaluate the delay discounting as potential components in models of adolescent obesity. Anthropometry and body composition measurements were assessed in adolescents. The cortisol reactivity to Trier Social Stress Test for Children (TSST-C) and delay discounting were measured. The result showed increased cortisol reactivity and greater delay discounting were associated with higher PBF in girls. Structural equation modeling supported greater delay discounting as a mediator of relations between increased cortisol reactivity and PBF in adolescent girls. The proposed mediation model indicated that cortisol reactivity is linked to PBF through delay discounting, thereby supporting a significant indirect relationship. The direct relationship between increased cortisol reactivity and higher PBF was significant in a model that did not include delay discounting, and was still significant in the mediation model that included delay discounting. This study provides the first evidence that greater delay discounting may partially account for the relationship of hyperactivity of the HPA-axis and higher PBF in girls.

Body composition of women and men with complete motor paraplegia.

OBJECTIVES: To examine body composition, including the relationship between body mass index (BMI) and total body fat, in women and men with complete motor paraplegia and to make comparisons with able-bodied controls. METHODS: In 13 subjects with traumatic, complete motor paraplegia (six women, seven men) and 39 sex-, age-, and BMI-matched controls from the community (18 women, 21 men), we measured total and regional (upper extremities, trunk, and lower extremities) lean and fat mass using total body dual-energy X-ray absorptiometry. RESULTS: Both women and men with paraplegia had significantly lower lean mass in their lower extremities, as would be expected, and in their total body when compared with controls. However, they had significantly greater lean mass in their upper extremities than controls (4.4 kg vs. 3.6 kg, P = 0.004 and 8.6 kg vs. 6.7 kg, P < 0.001 in women and men, respectively); all subjects with paraplegia studied used manual wheelchairs. Although total body fat mass was significantly greater in women (P = 0.010) and men (P = <0.001) with paraplegia compared with controls, for the equivalent total body fat mass, BMI was actually lower in women and men with paraplegia than controls (e.g. 20.2 kg/m² vs. 25.0 kg/m², respectively). CONCLUSION: We report on body composition in persons with complete motor paraplegia, including women on whom limited information is currently available. Our results support the need to define better assessments of obesity in both women and men following spinal cord injury, particularly of central body fat distribution, as BMI underestimates adiposity in this population.

Percent body fat more associated with perioperative risks after total joint arthroplasty than body mass index.

Understanding the impact of obesity on elective total joint arthroplasty (TJA) remains critical. Perioperative outcomes were reviewed in 316 patients undergoing primary TJA. Higher percent body fat (PBF) was associated with postoperative blood transfusion, increased hospital length of stay (LOS) >3 days, and discharge to an extended care facility while no significant differences existed for BMI. Additionally, PBF of 43.5 was associated with a 2.4× greater likelihood of blood transfusion, PBF of 36.5 with a 1.9× greater likelihood for LOS >3 days, and PBF of 36.0 with a 1.4× greater likelihood for discharge to an extended care facility. PBF may be a more effective measure than BMI to use in screening for perioperative risks and acute outcomes associated with obese total joint patients.

A More Comfortable Method for Hydrostatic Weighing: Head above Water at Total Lung Capacity.

Hydrostatic weighing (HW) requires full submersion with the lungs at residual volume (RV) which is uncomfortable. Therefore, the purpose of this study was to find a more comfortable way to complete HW. A HW system was used to complete three comparisons: comparison 1: change in head position (head above water vs. head below water (HAW vs. HBW)), comparison 2: change in lung volume (total lung capacity (TLC) vs. RV), and comparison 3: change in head and lung volume changes. Participants were separated by males (n = 64) and females (n = 58). Comparison 1: HAW resulted in higher mean percent body fat (PBF) than HBW (4.5% overall, 3.8% in males, 5.4% in females, p < 0.05). Comparison 2: TLC resulted in lower mean PBF than RV (5.1% overall, 5.3% in males, 4.8% in females, p < 0.05). Comparison 3: HAW@TLC resulted in significantly lower (1.5% lower, p = 0.003) mean PBF for males but was not significantly lower for females or overall (0.6% higher, p = 0.39, 0.6% lower, p = 0.18, respectively) compared to HBW@RV. In conclusion, keeping the head above water and taking a deep inhale makes HW a more enjoyable, and accessible experience for everyone while still producing accurate PBF results.

Body composition in early pubescent children with obesity: effects following 1 year of nonintervention.

Little is known about whether body composition changes differently between children with and without obesity following 1 year of nonintervention. Therefore, we investigated body composition in early pubescent children (8-12 yr) with and without obesity before and after a period of 1 year of nonintervention. Early pubescent children (8-12 yr; Tanner stage ≤ 3) with (body mass index, BMI ≥ 95th percentile) and without obesity (15th < BMI < 85th percentile) were recruited. At baseline, 88 children (n = 25 without obesity) completed dual-energy X-ray absorptiometry imaging (DXA) for body composition measurements [%body fat, fat mass, fat-free mass (FFM)]. One year later, 47 participants (n = 15 without obesity) returned for repeat testing. The children without obesity were older (11.0 ± 1.0 vs. 10.0 ± 1.2 yr; means ± SD) (P = 0.013). There was no group difference in height, and both groups increased in height similarly after 1 year (147.7 ± 8.9 to 154.5 ± 9.2 cm without vs. 145.6 ± 5.8 to 152.5 ± 5.9 cm with obesity) (P < 0.001). Weight was greater (P < 0.001) in children with obesity at baseline as was the increase in weight after 1 yr (9.25 vs. 5.82 kg) (interaction, P = 0.005). Fat mass increased by 4.4 kg in children with obesity and by 1.1 kg in children without obesity (interaction, P < 0.001). However, there was no difference in fat-free mass between those with and without obesity at baseline (29.9 ± 5.9 vs. 31.6 ± 4.8 kg) (P = 0.206) with both groups increasing similarly over 1 year (gain of 4.87 vs. 4.85 kg with and without obesity, respectively). Without intervention, the increase in fat mass is four times greater in children with obesity after 1 year as compared with children without obesity.NEW & NOTEWORTHY Little is known about changes in body composition in children with and without obesity following 1 year of nonintervention. We report that without intervention, fat mass gain is significantly greater in children with obesity after 1 year compared with those without obesity. Body mass index (BMI) and %body fat measurements after 1 year yielded no significant increase suggesting that BMI and %fat alone are not suitable measures for tracking changes in adiposity among children.