No abstract

Psychopathology in obese youth is well known in clinical samples but this study suggests that obese youth in the community may be at increased risk of developing body dissatisfaction, dietary restraint, and depressive symptoms compared with overweight or normal weight youth.

Background: Abdominal obesity, particularly visceral adipose tissue (VAT), is associated with an increased risk of coronary heart disease (CHD). Despite an elevated risk of CHD mortality in persons with spinal cord injury (SCI), neither abdominal adipose tissue accumulation nor the validity of waist circumference (WC) has been determined in persons with SCI. Objectives: The objectives of this study were to compare total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and the ratio of VAT to SAT (VAT:SAT) between adults with SCI and age-, sex-, and WC-matched ablebodied (AB) controls and to determine the relation between WC and VAT in both groups. Design: Thirty-one men and women (n ҃ 15 SCI and 16 AB) with a mean (ȀSD) age of 38.9 Ȁ 7.9 y participated in this cross-sectional study. Abdominal adipose tissue was quantified by computed tomography at L 4 -L 5 . WC was measured at 3 sites: lowest rib, iliac crest, and the midpoint between the lowest rib and iliac crest. Results: Persons with SCI had a 58% greater mean VAT (P ϭ 0.003), 48% greater mean VAT:SAT (P ҃ 0.034), and 26% greater mean TAT (P ҃ 0.055) than did matched AB controls after differences in weight were accounted for. Mean SAT was not significantly different between groups. WC at all sites was correlated with VAT in both groups (SCI: 0.905 ͨ r ͨ 0.925; AB: 0.838 ͨ r ͨ 0.877; both P 0.001). Conclusions: High levels of VAT exist in young people with SCI who classify themselves as active and healthy. WC may be a valid surrogate measure of VAT in this population and serve as a tool for clinicians to identify those at risk of CHD.Am J Clin Nutr 2008; 87:600 -7.

Bioelectrical impedance analysis (BIA) is the most commonly used body composition technique in published studies. Herein we review the theory and assumptions underlying the various BIA and bioelectrical impedance spectroscopy (BIS) models, because these assumptions may be invalidated in clinical populations. Single-frequency serial BIA and discrete multifrequency BIA may be of limited validity in populations other than healthy, young, euvolemic adults. Both models inaccurately predict total body water (TBW) and extracellular water (ECW) in populations with changes in trunk geometry or fluid compartmentalization, especially at the level of the individual. Single-frequency parallel BIA may predict body composition with greater accuracy than the serial model. Hand-to-hand and leg-to-leg BIA models do not accurately predict percent fat mass. BIS may predict ECW, but not TBW, more accurately than single-frequency BIA. Segmental BIS appears to be sensitive to fluid accumulation in the trunk. In general, bioelectrical impedance technology may be acceptable for determining body composition of groups and for monitoring changes in body composition within individuals over time. Use of the technology to make single measurements in individual patients, however, is not recommended. This has implications in clinical settings, in which measurement of individual patients is important.

Study design: Cross-sectional, non-experimental design. Objectives: (1) Determine the sensitivity and specificity of the general population body mass index (BMI) cutoff for obesity (30 kg m À2 ) in a representative sample of persons with spinal cord injury (SCI); (2) develop a more sensitive BMI cutoff for obesity based on percentage of fat mass (%FM) and C-reactive protein (CRP). Setting: Ontario, Canada. Methods: A total of 77 community-dwelling adults with chronic SCI underwent anthropometric measures (%FM by bioelectrical impedance analysis, length, weight, BMI (kg m À2 )) and provided blood samples to determine CRP. Sensitivity and specificity analyses, piecewise regression, non-linear regression, and receiver-operator characteristic curves were used to determine new BMI cutoffs.

Study design: Literature review. Background: Increased fat mass and coronary heart disease (CHD) are secondary complications of chronic spinal cord injury (SCI). In able-bodied populations, body mass index (BMI, body weight (kg)/height (m 2 )) is a widely used surrogate marker of obesity and predictor of CHD risk. Waist circumference, an accurate and reproducible surrogate measure of abdominal visceral adipose tissue, is also associated with CHD risk (more so than BMI) in able-bodied populations. Objective: To review the literature on the accuracy of BMI and waist circumference as surrogate measures of obesity and CHD risk in persons with chronic SCI. Setting: Ontario, Canada. Methods: Literature review. Results: In the SCI population, BMI is an insensitive marker of obesity, explains less of the variance in measured percent fat mass than in the able-bodied, and is inconsistently related to CHD risk factors. This may be due to potential measurement error, and to the inability of BMI to distinguish between fat and fat-free mass and to measure body fat distribution. Waist circumference has not been validated as a surrogate measure of visceral adipose tissue, however preliminary evidence supports a relationship between waist circumference and CHD risk in the SCI population. Conclusions: We recommend that SCI-specific BMI classifications be determined. We also recommend that accuracy and reliability of waist circumference as a surrogate measure of visceral adipose tissue and CHD risk be determined in men and women with long-standing paraplegia and tetraplegia. Body mass index (BMI) as a marker of obesity in chronic SCIObesity is defined as an excess accumulation of fat mass. Able-bodied men and women p40 years are considered obese when fat mass exceeds 22-25 and 35% of body weight, respectively. 1,2 As individuals age, fat mass accrues at the expense of fat-free mass, so that at older ages percentage fat mass is higher, even in individuals who do not gain weight. 3 Thus, obesity in 41-60-yearold able-bodied men and women can be defined as a fat mass 425 and 438% of body weight, respectively. 2 Mean percent fat mass (measured by dual energy X-ray absorptiometry (DXA), isotope dilution or the threecompartment model) reported in cross-sectional studies of persons (mostly men) with chronic spinal cord injury (SCI) ranges from 23 to 35%. [4][5][6][7][8][9][10][11] The percentage of body weight as fat mass is 8-18% higher in SCI versus age-, height-and/or weight-matched able-bodied control subjects. These values are often consistent with the above definitions of obesity, and are summarized in Table 1. Accurate classification of an individual as normal weight, overweight or obese requires measurement of body composition. However, measuring fat mass can be difficult and expensive, and no accurate method is easily available for routine clinical use. Therefore, the body mass index (BMI) is widely used. Expressed as weight (kg) divided by height (m 2 ), BMI allows classification of able-bodied adults as underweight, normal we...

BUCHHOLZ, ANDREA C., COLLEEN F. MCGILLIVRAY, AND PAUL B. PENCHARZ. Physical activity levels are low in free-living adults with chronic paraplegia. Obes Res. 2003;11:563-570. Objectives: To compare physical activity levels (PALs) of free-living adults with chronic paraplegia with World Health Organization recommendations and to compare energy expenditure between persons with complete vs. incomplete paraplegia. Research Methods and Procedures: Twenty-seven euthyroid adults (17 men and 10 women) with paraplegia (12.5 Ϯ 9.5 years since onset; 17 with complete lesions and 10 with incomplete lesions) participated in this cross-sectional study. Resting metabolic rate was measured by indirect calorimetry and total daily energy expenditure (TDEE) by heart rate monitoring. PAL was calculated as TDEE/resting metabolic rate. Total body water was measured by deuterium dilution and fat-free mass (FFM) and fat mass (FM) by calculation (FFM ϭ total body water/0.732; FM ϭ weight Ϫ FFM). Obesity was defined using the following percentage FM cutoffs: men 18 to 40 years Ͼ22% and 41 to 60 years Ͼ25%; and women 18 to 40 years Ͼ35% and 41 to 60 years Ͼ38%. Results: Nineteen subjects (70.4%; 13 men and six women) were obese. Fifteen subjects (56%) engaged in structured physical activity 1.46 Ϯ 0.85 times during the observation period for a mean of 49.4 Ϯ 31.0 minutes per session. Despite this, mean PAL of the group was 1.56 Ϯ 0.34, indicative of limited physical activity. TDEE was 24.6% lower in subjects with complete paraplegia (2072 Ϯ 505 vs. 2582 Ϯ 852 kcal/d, p ϭ 0.0372). Discussion: PAL of the group was low, indicating that persons with paraplegia need to engage in increased frequency, intensity, and/or duration of structured physical activity to achieve a PAL Ն1.75 and, thereby, to offset sedentary activities of daily living.

FFM, BCM, and RMR, but not obligatory TEF, are lower in paraplegics than in control subjects. RMR does not differ between control and paraplegic subjects after adjustment for FFM, indicating similar metabolic activity in the fat-free compartment of the body.