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Cited by 84Nutrition and Health in AgingPhysical Activity and HealthAging, Health, and Disability

Effects of Physical Activity and Body Composition on Functional Limitation in the Elderly: Application of the Marginal Structural Model

Tager, Ira B., Haight, Thaddeus, Sternfeld, Barbara, Yu, Zhuo, van Der Laan, Mark·2004·Epidemiology
DOI 10.1097/01.ede.0000128401.55545.c6
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Abstract

BACKGROUND: Study of the influence of physical activity and body composition in the context of the disablement process requires analytic techniques that can address time-dependent confounding related to exposures for the occurrence of functional limitation and disability. METHODS: We applied logistic marginal structural models to explore causal relationships between leisure time physical activity and a measure of relative muscle mass (the lean:fat mass ratio) and self-reported functional limitation. Subjects (n = 1655) were members of a population-based cohort recruited in Sonoma, California, in 1993-1994 (median age 70 years); they were surveyed 3 times over 6.5 years. RESULTS: Based on the marginal structural model, the causal odds ratio for functional limitation with a 0.5-unit increment in relative muscle mass was 0.56 in women (95% CI = 0.46-0.67). This reduction in odds was not altered by adjustment for baseline covariates. The corresponding causal odds ratio in men was 0.77 (0.65-0.92). This also was not influenced by baseline covariates or levels of physical activity. There was evidence for an independent causal effect of increased levels of physical activity on reduction of odds of functional limitation for men but not for women. Obese women experienced no protective effect of increased lean-to-fat mass. Normal-weight women experienced a benefit with increasing levels of physical activity. CONCLUSIONS: Marginal structural models provide a means to address time-dependent confounding, which can occur in longitudinal studies. These analyses indicate that leisure time physical activity exerts its beneficial effects through reductions in fat mass relative to lean body mass.

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  • Excess body fat is poorly estimated by BMI in sedentary subjects or those with chronic diseases.

    “This finding suggests that excess body fat is poorly estimated by BMI in sedentary subjects or those with chronic diseases.”

    From Overweight and obesity in a Swiss city: 10-year trends (2007) · cites this paper as [29]

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Authors
Tager, I. B., Haight, T., Sternfeld, B., Yu, Z., & van Der Laan, M.
Affiliations
  • University of California, Berkeley (US)
  • Kaiser Permanente (US)
Corresponding author
  • Tager, Ira B.
  • Haight, Thaddeus
ORCID
Haight, Thaddeus
Venue
Epidemiology
Publisher
Ovid Technologies (Wolters Kluwer Health)
Published
2004-07
Volume
15
Issue
4
Pages
479-493
ISSN
1044-3983 (ISSN-L)
DOI
10.1097/01.ede.0000128401.55545.c6
OpenAlex
W2073179351
Cited by
84
References
71
Citations by year
2025: 1 · 2023: 1 · 2022: 1 · 2021: 4 · 2020: 1 · 2019: 2 · 2017: 4 · 2016: 3 · 2015: 2 · 2014: 7 · 2013: 5 · 2012: 6
FWCI
4.53
Type
journal article
Language
en
Open access
closed
Locations
  • Epidemiology (publishedVersion)
  • PubMed (publishedVersion)
Funders
National Institute on Aging (R01 AG09389, R01AG009389)
Topics
  • Health Sciences › Medicine › Physiology › Nutrition and Health in Aging
  • Health Sciences › Medicine › Physiology › Physical Activity and Health
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Aging, Health, and Disability
Keywords
physical activity, body composition, functional limitations, older adults, muscle mass, obesity, time-varying confounding, marginal structural models, causal inference, sex differences
MeSH terms
Activities of Daily Living, Age Factors, Aged, Aged, 80 and over, Aging, Anthropometry, Body Composition, California, Cross-Sectional Studies, Female, Persons with Disabilities, Disabled Persons, Health Status, Humans, Male, Middle Aged, Surveys and Questionnaires, Sex Factors, Skinfold Thickness, Time Factors, Exercise, Confounding Factors, Epidemiologic, Logistic Models, Frail Elderly, Electric Impedance

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