The Effects of Fitness and Fatness on Balance and Gait in Elderly Men.

Abstract

0355 Reductions in physical activity have been linked to declines in cardiovascular (CV) fitness and increases in obesity across the lifespan. The effects of CV fitness and body fatness on function, as estimated by balance and gait outcomes, have been understudied in the elderly. Rising rates of obesity and physical inactivity in the aged may contribute to declines in static and dynamic balance, as well as ambulatory function. PURPOSE: To determine if fitness and body fatness impact balance and gait measures in a group of healthy, community-dwelling, elderly males. METHODS: Sixteen males (M ± SD: 72.1 ± 4.7 y), upon enrollment in a randomized clinical trial investigating the effects of exercise on immune function, volunteered for this study. CV fitness was determined from a maximal oxygen uptake test, expressed relative to body weight (VO2max). Body composition (%Fat) was determined by DXA. Gait performance was assessed using timed stair descent (STdown) and ascent (STup), timed 8-Foot Up and Go (UP-GO), and self-paced 7-meter walk with obstacle (WLK). Balance performance was assessed using: 1) the Berg balance scale (BERG), a quantitative method of assessing balance function that simulates conditions encountered in daily life; 2) the composite score on the EquiTest computerized dynamic posturography system (EQU); and 3) standing postural sway and limits of stability using a force platform (SWAY). RESULTS: Average VO2max was 21.9 ± 4.6 m1/kg/min and body fatness was 26.8 ± 6.1 %Fat, reflecting typical values for healthy elderly males. Positive relations existed between %Fat and WLK (r = 0.55, p < 0.05), UP-GO (r = 0.68, p < 0.01), STdown (r = 0.58, p < 0.05), STup (r = 0.63, p < 0.05). Additionally, strong negative relations existed between VO2max and UP-GO (r = −0.62, p < 0.05), STdown (r = −0.70, p < 0.01), ST up (r = −0.72, p < 0.01). Due to the strong relation between %Fat and VO2max (r = −0.62, p < 0.05), partial correlations were also examined for the above dependent measures. When controlling for VO2max, only the relation between %Fat and WLK remained significant (r = 0.58, p < 0.05); however, when controlling for %Fat, the relation between VO2max and UP-GO, STdown and STup dissolved suggesting that body fatness is more important than cardiovascular fitness for gait performance. No relation existed between %Fat or VO2max and BERG, EQU, and SWAY. CONCLUSION: As expected, neither fitness nor fatness affect static balance nor postural sway control measures. Independent of fitness, fatness negatively impacts gait performance. Further study is needed regarding the relation between physical activity, obesity and balance and gait performance in the elderly. Supported by NIH AG18861 to Woods