Aging and Energetics among Persons with Mobility Disabilities

Background: Aging involves bioenergetic declines that include post-mitotic neural and muscular tissue plus extracellular matrix. With a growing population of older adults, successful aging strategies for persons with disabilities are a priority. Allometric aging models indicate VO2 max as a useful bioenergetics measure.

Purpose: We evaluated VO2 max, bone density, bioelectric impedance estimates of body fat and water, cardiovascular, and other laboratory data for persons with mobility limitations as compared to persons without disabilities in the 2003-2004 National Health and Nutrition Examination Survey (NHANES).

Significance: Research has demonstrated greater risk for secondary conditions, obesity, and cardiovascular risk among persons with mobility limitations. This study addresses physiological measures that can facilitate healthy aging for persons with disabilities.

Methodology: The 2003-2004 NHANES study was the last study period to include VO2 max examinations for a participant subsample. Analyses included ordinary least squares regression and ANCOVA. Dependent variables included VO2 max and percentage body fat. Independent variables included mobility limitations/functioning (e.g. walking up ten steps, bending/kneeling), blood pressure, BMI, and bone densities for separate female and male analyses.

Conclusions: VO2 max significantly declined with age (p < .006) for females but not for males, and there was no significant difference across ages for persons with and without mobility limitations. Percentage body fat was significantly associated with age (p < .03) and disability (p < .02) for males but not for females. Persons with mobility limitations were underrepresented due to exclusion criteria. We suggest alternative bioenergetic measures for persons with functional limitations.