PMID- 17392701
OWN - NLM
STAT- MEDLINE
DCOM- 20080701
LR  - 20080305
IS  - 0954-3007 (Print)
IS  - 0954-3007 (Linking)
VI  - 62
IP  - 3
DP  - 2008 Mar
TI  - Changes in thoracic gas volume with air-displacement plethysmography after a 
      weight loss program in overweight and obese women.
PG  - 444-50
AB  - OBJECTIVE: This study was designed to compare measured and predicted thoracic gas 
      volume (V (TG)) after weight loss and to analyze the effect of body composition 
      confounders such as waist circumference (WC) on measured V (TG) changes. DESIGN: 
      Prospective intervention study. SETTING: Outpatient University Laboratory, 
      Lisbon, Portugal. SUBJECTS: Eighty-five overweight and obese women (body mass 
      index = 30.0+/-3.5 kg/m(2); age = 39.0+/-5.7 years) participating in a 16-month 
      university-based weight control program designed to increase physical activity 
      and improve diet. METHODS: Body weight (Wb), body volume (Vb), body density (Db), 
      fat mass (FM), percent fat mass (%FM) and fat-free mass (FFM) were assessed by 
      air-displacement plethysmography (ADP) at baseline and at post-intervention (16 
      months). The ADP assessment included a protocol to measure V (TG) and a 
      software-based predicted V (TG). Dual-energy X-ray absorptiometry (DXA) (Hologic 
      QDR 1500) was also used to estimate FM, %FM and FFM. Maximal oxygen uptake (VO(2) 
      max) was assessed with a modified Balke cardiopulmonary exercise testing protocol 
      with a breath-by-breath gas analysis. RESULTS: Significant differences between 
      the baseline and post-weight loss intervention were observed for body weight and 
      composition (Vb, Db, %FM, FM and FFM), and measures of V (TG) (measured: 
      Delta=0.2 l, P<0.001; predicted: Delta=0.01 l, P<0.010) variables. Measured V 
      (TG) change was negatively associated with the change in the WC (P=0.008), 
      controlling for VO(2) max and age (P=0.007, P=0.511 and P=0.331). Linear 
      regression analysis results indicated that %FM and FM using the measured and 
      predicted V (TG) explained 72 and 76%, and 86 and 90% respectively, of the 
      variance in %FM and FM changes using dual-energy x-ray absorptiometry. 
      CONCLUSIONS: After weight loss, measured V (TG) increased significantly, which 
      was partially attributed to changes is an indicator of body fat distribution such 
      as WC. Consequently, measured and predicted V (TG) should not be used 
      interchangeably when tracking changes in body composition. The mechanisms 
      relating the reduction of an upper body fat distribution with an increase 
      measured V (TG) are worthy of future investigation.
FAU - Minderico, C S
AU  - Minderico CS
AD  - Exercise and Health Laboratory, Faculty of Human Movement-Technical University of 
      Lisbon, Estrada da Costa, Portugal.
FAU - Silva, A M
AU  - Silva AM
FAU - Fields, D A
AU  - Fields DA
FAU - Branco, T L
AU  - Branco TL
FAU - Martins, S S
AU  - Martins SS
FAU - Teixeira, P J
AU  - Teixeira PJ
FAU - Sardinha, L B
AU  - Sardinha LB
LA  - eng
PT  - Journal Article
DEP - 20070328
PL  - England
TA  - Eur J Clin Nutr
JT  - European journal of clinical nutrition
JID - 8804070
SB  - IM
MH  - Absorptiometry, Photon
MH  - Adult
MH  - Body Composition/*physiology
MH  - Body Fat Distribution
MH  - Body Mass Index
MH  - Diet, Reducing
MH  - Exercise/physiology
MH  - Female
MH  - Humans
MH  - Obesity/*physiopathology/therapy
MH  - Overweight/*physiopathology/therapy
MH  - *Oxygen Consumption
MH  - Plethysmography/*methods
MH  - Predictive Value of Tests
MH  - Prospective Studies
MH  - Weight Loss/*physiology
EDAT- 2007/03/30 09:00
MHDA- 2008/07/02 09:00
CRDT- 2007/03/30 09:00
PHST- 2007/03/30 09:00 [pubmed]
PHST- 2008/07/02 09:00 [medline]
PHST- 2007/03/30 09:00 [entrez]
AID - 1602709 [pii]
AID - 10.1038/sj.ejcn.1602709 [doi]
PST - ppublish
SO  - Eur J Clin Nutr. 2008 Mar;62(3):444-50. doi: 10.1038/sj.ejcn.1602709. Epub 2007 
      Mar 28.