Fat distribution and end-expiratory lung volume in lean and obese men and women.
BACKGROUND
Although obesity significantly reduces end-expiratory lung volume (EELV), the relationship between EELV and detailed measures of fat distribution has not been studied in obese men and women. To investigate, EELV and chest wall fat distribution (ie, rib cage, anterior subcutaneous abdominal fat, posterior subcutaneous fat, and visceral fat) were measured in lean men and women (ie, < 25% body fat) and obese men and women (ie, > 30% body fat).


METHODS
All subjects underwent pulmonary function testing, hydrostatic weighing, and MRI scans. Data were analyzed for the men and women separately by independent t test, and the relationships between variables were determined by regression analysis.


RESULTS
All body composition measurements were significantly different among the lean and obese men and women (p < 0.001). However, with only a few exceptions, fat distribution was similar among the lean and obese men and women (p > 0.05). The mean EELV was significantly lower in the obese men (39 +/- 6% vs 46 +/- 4% total lung capacity [TLC], respectively; p < 0.0005) and women (40 +/- 4% vs 53 +/- 4% TLC, respectively; p < 0.0001) compared with lean control subjects. Many estimates of body fat were significantly correlated with EELV for both men and women.


CONCLUSIONS
In both men and women, the decrease in EELV with obesity appears to be related to the cumulative effect of increased chest wall fat rather than to any specific regional chest wall fat distribution. Also, with only a few exceptions, relative fat distribution is markedly similar between lean and obese subjects.
Babb
Tony G
TG
Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center/Presbyterian Hospital of Dallas, Dallas, TX. Electronic address: TonyBabb@TexasHealth.org.
Wyrick
Brenda L
BL
Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center/Presbyterian Hospital of Dallas, Dallas, TX.
DeLorey
Darren S
DS
Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB, Canada.
Chase
Paul J
PJ
Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center/Presbyterian Hospital of Dallas, Dallas, TX.
Feng
Mabel Y
MY
Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center/Presbyterian Hospital of Dallas, Dallas, TX.
D050153:Abdominal Fat; D000328:Adult; D050218:Body Fat Distribution; D015992:Body Mass Index; D016022:Case-Control Studies; D005105:Expiratory Reserve Volume / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009765:Obesity / Q000473:pathology* / Q000503:physiopathology*; D011237:Predictive Value of Tests; D035441:Thoracic Wall