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Background & Aims: Investigating the effect of leptin on energy expenditure in undernutrition might lead to a better understanding of the role of leptin in regulating body weight in humans., Methods: 73 underweight female adolescents with anorexia nervosa (AN) were compared with 23 healthy normal weight (nwC), and 9 overweight girls (OW); 37 AN were followed during 7 months of weight recovery. Resting energy expenditure (REE, by indirect calorimetry), body composition (fat mass, FM; lean tissue mass, LTM; by Dual-Energy X-Ray Absorptiometry) and plasma hormones of leptin and 3,5,3'-Triiodothyronine (T(3)) were measured., Results: In underweight, leptin, T(3) and REE adjusted for lean tissue mass (REE(LTM)) were decreased; in OW, FM and leptin were increased at unchanged T(3) and REE(LTM). There was a significant positive relation between FM and leptin at low and normal (AN, r(2) = 0.26; nwC, r(2) = 0.51, p < 0.001), but not at high adiposity. Leptin and REE(LTM) were positively associated in underweight (r(2) = 0.14, p = 0.001) but not in normal or overweight subjects. T(3) was linearly related to REE(LTM) over the whole range of adiposity (r(2) = 0.42, p < 0.001). With weight gain in AN (5.0 ± 3.5 kg) the relationship between leptin and REE(LTM) changed toward the conditions seen in normal weight controls., Conclusions: At low adiposity the interrelated fall of leptin and REE reflect an adaptive mechanism to preserve body weight. High leptin production associated with excessive adiposity was without effect on metabolic adaptation., (Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Objective: Novelty and routinization-related information processing disturbances were examined in adolescent males with ADHD using an oddball paradigm and electrophysiological measurement of theta (4-7Hz) activity., Methods: Fifty-four unmedicated adolescent males (12-18years) with Attention Deficit Hyperactivity Disorder (ADHD) and matched controls performed an auditory oddball task. Theta activity was sub-averaged, and Fourier Integrals with simultaneous measurement of electrodermal activity (EDA) was used to index response to stimulus novelty and routinization., Results: ADHD participants showed an overall increase in theta activity to both novel and routine stimuli relative to controls. While controls showed increased theta activity in response to novel compared to routine targets across the brain, ADHD participants did not show this novelty-related increase in theta activity in the right anterior/frontal brain., Conclusions: The findings of this study are consistent with disturbances in theta activity and the brain substrates of novelty relative to routinization-related processing in ADHD., Significance: These findings show that there are distinct alterations in theta activity related to stimulus novelty and routinization during an auditory oddball task in ADHD, and they highlight the value of using an event-related approach to elucidate the neural substrates of stimulus processing in ADHD., (Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Background: Body weight provides limited information about nutritional status of patients with anorexia nervosa (AN)., Objectives: Our objectives were to determine body composition (BC) changes, to find clinical predictors and endocrine correlates of total body protein (TBPr) depletion, and to compare results on fat mass (FM) obtained with anthropometry (skinfold measurements) and dual-energy X-ray absorptiometry (DXA) in patients with AN., Design: Body weight, body mass index (BMI; in kg/m(2)), BC (with DXA and skinfold measurements), and TBPr [with in vivo neutron activation analysis (IVNAA)] was assessed in 50 AN patients (15.2 y) and 40 healthy sex- and age-matched controls. In 47 AN patients and 22 controls, hormone concentrations were measured., Results: In AN patients, body weight (44.4 +/- 5.5 kg), BMI (16.7 +/- 1.6), and FM(DXA) (7.0 +/- 3.4 kg) were lower than in controls. Lean tissue mass by DXA (LTM(DXA)) was similar in AN patients and controls (35.7 +/- 4.3 compared with 35.8 +/- 4.5 kg), but TBPr was 87% of that of controls (8.1 +/- 1.0 compared with 9.2 +/- 1.2 kg; P < 0.001). Cortisol was high, testosterone was unchanged, and estradiol and insulin-like growth factor I were low. Severe protein depletion measured by IVNAA seen in 17 AN patients could not be identified with simpler methods. All except 1 of 26 AN patients with a BMI > 16.5 had normal TBPr. The difference in individual percentage of body fat measured with DXA and skinfold measurements came up to 9%., Conclusion: The severe protein depletion in 34% of AN patients was not accurately identified by LTM(DXA) or simpler methods, but a BMI > 16.5 indicated normal TBPr. Future studies need to compare DXA and skinfold measurements with a reference technique to assess FM in AN patients.

Objective: This study examines the utility of new measures of event-related spatio-temporal waves in the EEG as a marker of ADHD, previously shown to be closely related to the P3 ERP in an adult sample., Methods: Wave activity in the EEG was assessed during both an auditory Oddball and a visual continuous performance task (CPT) for an ADHD group ranging in age from 6 to 18 years and comprising mostly Combined and Inattentive subtypes, and for an age and gender matched control group., Results: The ADHD subjects had less wave activity at low frequencies ( approximately 1 Hz) during both tasks. For auditory Oddball targets, this effect was shown to be related to smaller P3 ERP amplitudes. During CPT, the approximately 1 Hz wave activity in the ADHD subjects was inversely related to clinical and behavioral measures of hyperactivity and impulsivity. CPT wave activity at approximately 1 Hz was seen to "normalise" following treatment with stimulant medication., Conclusions: The results identify a deficit in low frequency wave activity as a new marker for ADHD associated with levels of hyperactivity and impulsivity., Significance: The marker is evident across a range of tasks and may be specific to ADHD. While lower approximately 1 Hz activity partly accounts for reduced P3 ERPs in ADHD, the effect also arises for tasks that do not elicit a P3. Deficits in behavioral inhibition are hypothesized to arise from underlying dysregulation of cortical inhibition.

Background: Little recent and accurate information about body protein content in healthy adolescent girls is available., Objective: The objective was to assess the total body nitrogen (TBN) and total body protein (TBPr) contents of fat-free mass (P:FFM) in a group of healthy adolescent girls and to validate previously published TBN prediction equations., Design: TBN was measured with in vivo neutron activation analysis (TBNNAA). Bone mineral density and FFM were measured with dual-energy X-ray absorptiometry (FFMDXA), total body water and FFM were measured with bioimpedance analysis, and FFM was assessed by measuring skinfold thicknesses in 51 girls with a mean (+/- SD) age of 14.7 +/- 0.7 y. The validity of the TBN prediction equations was assessed with Bland-Altman analysis., Results: TBNNAA in our adolescent group was higher (1.49 kg) than values reported in earlier studies of women (1.25 and 1.31 kg), and P:FFM was slightly higher (23%) than that documented in adults (19-21%). Previously published TBN equations showed either systematic bias or wide limits of agreement., Conclusion: A predictive equation derived from the present study population based on FFMDXA improves the prediction of TBN for groups of young girls but may not be helpful for individuals in clinical settings.

Objective: Attention Deficit Hyperactivity Disorder (ADHD) occurs more frequently in male children and adolescents than in females, with a ratio of approximately 3 to 1. We determined whether psychophysiological differences are associated with the expression of ADHD in males and females, using simultaneously recorded electroencephalography (EEG) and electrodermal activity (EDA)., Methods: Quantitative EEG and EDA measures were acquired simultaneously and continuously (2min) during an eyes closed resting condition for 70 ADHD adolescents (48 males, 22 females) and their age- and sex-matched controls., Results: Males and females with ADHD were differentiated by both EEG theta activity and EDA. ADHD males showed increased theta (widespread), whereas ADHD females showed a localised frontal enhancement of theta with reduced rate of EDA decrement. These sex differences were unrelated to ADHD subtype., Conclusions: These findings suggest that different psychophysiological processes may underlie ADHD in each sex. The profile of theta enhancement in ADHD males is consistent with a developmental deviation model of ADHD, whereas ADHD in females may be better understood within an arousal model, which emphasizes both central and autonomic function., Significance: These findings highlight the potential for concurrent EDA measures to inform EEG studies of ADHD, particularly in regard to sex differences.

Background: Malnourished patients with anorexia nervosa have altered body composition characterized by depletion of fat and fat-free mass., Objectives: The objectives of this study were to assess the body composition of adolescents with anorexia nervosa compared with that of control subjects and to investigate the relation between simple anthropometric measures and reference techniques for measuring body composition., Design: Twenty-three adolescent females with anorexia nervosa aged 15.46 +/- 1.34 y (x +/- SD) were studied. Body composition was measured by anthropometry, dual-energy X-ray absorptiometry (DXA) (for body fat), and prompt gamma in vivo neutron activation analysis [for total body nitrogen (TBN)]. Twenty-five female subjects provided the control DXA data. TBN measurements were compared with prediction equations based on sex, height, age, and weight., Results: Anorexia nervosa patients had significantly lower weight (40.2 +/- 4.6 kg), body mass index (in kg/m(2): 15.3 +/- 1.2), percentage of body fat (DXA) (13.8 +/- 5.8%), percentage of TBN predicted for age (73 +/- 10%), trunk fat (2.1 +/- 1.0 kg), leg fat (2.6 +/- 1.1 kg), and trunk-to-leg fat ratio than did control subjects (P < 0.05). In anorexia nervosa patients, significant correlations were found between triceps skinfold thickness and percentage of body fat (r = 0.83), body mass index and percentage of body fat (r = 0.46), and body weight and TBN (r = 0.84, P < 0.05)., Conclusions: Hospitalized adolescent females with anorexia nervosa are depleted of total body fat and protein. We identified 3 simple anthropometric measures (triceps skinfold thickness, BMI, and body weight) that can be used to assess body composition and nutritional status in malnourished adolescents with anorexia nervosa.