Effects of Changes in Regional Body Composition on Physical Function in Older Adults: A Pilot Randomized Controlled Trial.
OBJECTIVE
Obesity exacerbates age-related physical disability; however, observational studies show that any weight loss in old age is associated with greater risk of mortality. Conversely, randomized controlled trials in older adults show that weight loss is beneficial. The discrepancy may be due to weight loss intention and differential changes to regional body composition. The purpose of this research was to evaluate the independent role of regional body composition remodeling in improving physical function.


METHODS
Pilot Randomized Controlled Trial.


METHODS
Community based research center.


METHODS
Thirty-six community dwelling, overweight to moderately obese (BMI 28.0-39.9 kg/m2) older adults (age 70.6±6.1 yrs).


METHODS
Physical activity plus weight loss (PA+WL, n=21) or PA plus successful aging (SA) education. PA consisted primary of treadmill walking supplemented with lower extremity resistance and balance training. The WL program was based on the Diabetes Prevention Project and aimed at achieving a 7% weight loss by cutting calories, specifically those from fat.


METHODS
At baseline, 6- and 12-months, body composition was measured using computerized tomography and dual x-ray absorptiometry. Abdominal visceral (VAT) and thigh intermuscular (IMAT) adipose tissue were quantified. Physical function was assessed using the short physical performance battery (SPPB).


RESULTS
Separate multivariable linear regression models with both groups combined demonstrated that decreases in IMAT and VAT were significantly associated with improvements in SPPB (P<0.05) independent of change in total fat mass. PA+WL improved SPPB scores from baseline (0.8±1.4, P<0.05), whereas PA+SA did not; however no intergroup difference was detected. Of note, these effects were mainly achieved during the intensive intervention phase.


CONCLUSIONS
Decreases in IMAT and VAT are important mechanisms underlying improved function following intentional weight loss plus physical activity.
Nancy W. Glynn, PhD, 130 DeSoto Street, A531 Crabtree Hall Pittsburgh, PA 15261, 412.383.1309 (phone), 412.624.7397 (fax), glynnn@edc.pitt.edu.
A J
AJ
Santanasto
A B
AB
Newman
E S
ES
Strotmeyer
R M
RM
Boudreau
B H
BH
Goodpaster
N W
NW
Glynn
D015502:Absorptiometry, Photon; D000203:Activities of Daily Living; D000273:Adipose Tissue / Q000378:metabolism*; D000368:Aged; D000375:Aging; D001823:Body Composition; D004038:Diet, Reducing; D005260:Female; D006266:Health Education; D006801:Humans; D050152:Intra-Abdominal Fat / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D056128:Obesity, Abdominal / Q000378:metabolism / Q000503:physiopathology; D010809:Physical Fitness; D010865:Pilot Projects; D055070:Resistance Training; D016138:Walking; D015431:Weight Loss