Longitudinal body composition changes in old men and women: interrelationships with worsening disability.
BACKGROUND
Few studies have evaluated prospectively age-related body composition changes and their relationships with worsening disability in the elderly population.


METHODS
Ninety-seven women and 62 men aged 71.4+/-2.2 and 71.6+/-2.2 years, respectively, at baseline underwent dual-energy x-ray absorptiometry determinations at baseline and at 2- and 5.5-year follow-up intervals to measure total body and leg fat (FM) and total, appendicular, and leg fat-free mass (FFM). Height, weight, body mass index (BMI), and waist circumference (as well as reported disabilities using a four-level scale) were evaluated at baseline and at 2- and 5.5-year follow-up.


RESULTS
In both sexes, total FM did not change significantly, while total, appendicular, and leg FFM significantly decreased over the study follow-up. In men and women losing weight, BMI, total and leg FM, and total, appendicular, and leg FFM significantly decreased. In weight-stable men and women, appendicular and leg FFM significantly decreased and BMI, waist circumference, and total FM significantly increased. Men lost significantly more total, appendicular, and leg FFM than did women, irrespective of whether they maintained or lost weight. Over the follow-up period, 43.3% of women and 43.5% of men declined in one or more levels of reported disability. We evaluated the effect of age, baseline BMI, FM, FFM, number of diseases, baseline 6-minute walking test, categories of weight change, total, appendicular, or leg FFM changes, total FM and waist changes on the probability of a decline in one or more levels of reported disability score over the follow-up period, taking into account sex. Patients losing appendicular and leg FFM were 2.15 and 2.53 times, respectively, more likely to report increased disability than were patients without FFM loss.


CONCLUSIONS
Reduction in appendicular or leg FFM was the main predictor of decline in one or more levels of reported disability in older men and women, and accounted for about a 2-fold increase in risk.
Fantin
Francesco
F
Division of Geriatric Medicine, University of Verona, Italy.
Di Francesco
Vincenzo
V
Fontana
Giorgia
G
Zivelonghi
Alessandra
A
Bissoli
Luisa
L
Zoico
Elena
E
Rossi
Andrea
A
Micciolo
Rocco
R
Bosello
Ottavio
O
Zamboni
Mauro
M
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001823:Body Composition; D015992:Body Mass Index; D006233:Persons with Disabilities; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D012727:Sex Characteristics