Background: Brown adipose tissue (BAT) was considered essentially nonexistent in adults until recent evidence obtained using 18-fluorodeoxyglucose (18-FDG) positron emission tomography/computed tomography. It seems to play a role in whole body metabolism, but it has not been evaluated in underweight conditions, such as in young females with constitutional leanness (CL) or anorexia nervosa (AN).
Subjects And Methods: Thirty-eight subjects were evaluated from October 2011 to March 2012 : 7 CL (21.7 ± 3.6 y, body mass index [BMI] 16.2 ± 1.0 kg/m(2)), 7 AN (23.4 ± 4.5 y, BMI 15.5 ± 0.8), 3 of the 7 AN after stable refeeding (R-AN, 21.3 ± 1.5 y, BMI 18.8 ± 1.1), and 24 normal weight (NW) women (25.6 ± 3.9 y, BMI 22.2 ± 1.5). Fasting resting metabolic rate and respiratory quotient were measured by indirect calorimetry, body composition by bioimpedentiometry (only in CL, AN, and refed AN), and BAT activity by 18-FDG positron emission tomography/computed tomography scan, all in standardized conditions.
Results: All CL (100%), none of the AN and refed AN (0%), and 3 of the 24 NW (12%) subjects showed FDG uptake. Average FDG maximum standardized uptake value was 11.4 + 6.7 g/mL in CL and 5.5 ± 1.2 g/mL (min 3.7, max 8.3) in the 3 NW subjects. In CL, the maximum standardized uptake value was directly correlated to resting metabolic rate, corrected for fat-free mass, and inversely correlated with respiratory quotient.
Conclusion: BAT activity has been shown in CL in resting thermoneutral conditions and may exert a role against adipose tissue deposition.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1210/jc.2012-2981 | DOI Listing |
Lancet Public Health
December 2024
Centre for Adolescent Health, Royal Children's Hospital, Parkville, VIC, Australia; Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC, Australia; Murdoch Children's Research Institute, Parkville, VIC, Australia.
Background: There are little recent data in China regarding contemporary nutritional inequities among children and adolescents, particularly in relation to urban-rural residence and regional socioeconomic status (SES). We aim to assess inequalities in thinness and obesity in Chinese children and adolescents.
Methods: Weight and height measurements for 1 677 261 children and adolescents aged 7-18 years were obtained from seven cycles of the Chinese National Surveys on Students Constitution and Health (1985, 1995, 2000, 2005, 2010, 2014, and 2019).
Metabolism
December 2024
Research Unit Analytical Pathology, Helmholtz Zentrum München, Neuherberg, Germany. Electronic address:
Eur J Appl Physiol
November 2024
Laboratory of the Metabolic Adaptations to Exercise Under Physiological and Pathological Conditions (AME2P), Clermont Auvergne University, CS 60026, 63178, Aubière Cedex, France.
Purpose: Individuals with constitutional thinness have been presented with a lower muscular energy metabolism at the cellular level but their effective aerobic capacities and exercise-related energy efficiency remains unexplored. The present study compares maximal and sub-maximal aerobic capacities between subjects with constitutional thinness and age-matched normal-weight ones.
Methods: Anthropometric measures, body composition (Dual-X-ray absorptiometry), physical activity and sedentary time (GT3x actigraphs), and maximal aerobic capacities (cycling test) were assessed in 18 constitutionally thin (CT-body mass index < 17.
Eur J Appl Physiol
November 2024
Laboratory of the Metabolic Adaptations to Exercise Under Physiological and Pathological Conditions (AME2P), Université Clermont Auvergne, CRNH, 63000, Clermont-Ferrand, France.
Purpose: While muscle mass and skeletal muscle fibers phenotype have been shown atypical in constitutional thinness (CT), force production capacities and its architectural determinants have never been explored. The present study compared muscle functionality and architecture between participants with CT and their normal-weight (NW) counterparts.
Methods: Anthropometry, body composition (Dual-X-ray Absorptiometry), physical activity/sedentary behavior (ActiGraph wGT3X-BT), ultrasound recording of the Vastus Lateralis (2D-ultrasound system), and functional capacities at maximal isometric and isokinetic voluntary contractions (MVC and MVC) during knee extension (isokinetic dynamometer chair Biodex) have been measured in 18 women with CT (body mass index < 17.
Appetite
April 2024
Université Clermont Auvergne, CRNH, AME2P, F-63000 Clermont-Ferrand, France. Electronic address:
While people with Constitutional Thinness (CT) declare a deep willingness to gain weight, there appetitive responses to energy balance manipulations remain unclear. The present work compares the effect of an acute exercise combined or not with an energy replacement load, on subsequent energy intake, appetite and food reward, between normal weight and women with CT. Anthropometric measurements, body composition (Dual X-ray absorptiometry-DXA) and aerobic capacity (VO2max) were assessed in 10 normal-weight (Body Mass Index-BMI): 20-25 kg/m) and 10 C T (BMI<17.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!