Activity Energy Expenditure and Mobility Limitation in Older Adults: Differential Associations by Sex

• Published in: American journal of epidemiology 2009-06, Vol.169 (12), p.1507-1516
• Main Authors: Manini, Todd M., Everhart, James E., Patel, Kushang V., Schoeller, Dale A., Cummings, Steve, Mackey, Dawn C., Bauer, Douglas C., Simonsick, Eleanor M., Colbert, Lisa H., Visser, Marjolein, Tylavsky, Frances, Newman, Anne B., Harris, Tamara B.
• Format: Article
• Language: English
• Subjects: Activities of Daily Living; Age Factors; Aged; Aged, 80 and over; aging; Aging - physiology; Analysis. Health state; Biological and medical sciences; Calorimetry; Confidence Intervals; Disability Evaluation; Energy Metabolism; Epidemiology; Exercise; Female; Gait - physiology; Gender differences; General aspects; Health Status; Humans; Longitudinal Studies; Male; Medical sciences; Mobility; Mobility Limitation; motor activity; Motor Activity - physiology; Older people; Original Contributions; Proportional Hazards Models; Public health. Hygiene; Public health. Hygiene-occupational medicine; sex; Sex Factors; Surveys and Questionnaires
• ISSN: 0002-9262; 1476-6256
• DOI: 10.1093/aje/kwp069

In this study, the authors aimed to determine whether higher activity energy expenditure, assessed by using doubly labeled water, was associated with a reduced decline in mobility limitation among 248 older community-dwelling US adults aged 70–82 years enrolled in 1998–1999. Activity energy expenditure was calculated as total energy expenditure (assessed over 2 weeks by using doubly labeled water) minus resting metabolic rate (measured with indirect calorimetry), with adjustment for the thermic effect of food. Across sex-specific tertiles of activity energy expenditure, men in the lowest activity group experienced twice the rate of mobility limitation as men in the highest activity group (41% (n = 18) vs. 18% (n = 8)). Conversely, women in the lowest and highest activity groups exhibited similarly high rates of mobility limitation (40% (n = 16) vs. 38% (n = 15)). After adjustment for potential confounders, men with higher activity energy expenditure levels continued to show reduced risk of mobility limitation (per standard deviation (284 kcal/day): hazard ratio = 0.61, 95% confidence interval: 0.41, 0.92). Women showed no association (per standard deviation (226 kcal/day): hazard ratio = 1.34, 95% confidence interval: 0.98, 1.85). Greater energy expenditure from any and all physical activity was significantly associated with reduced risk of developing mobility limitation among men, but not among women.