SIMILAR AGE-RELATED DECLINES IN MAXIMAL AEROBIC CAPACITY IN SEDENTARY HISPANIC AND CAUCASIAN WOMEN

Abstract

1427 Hispanic women may demonstrate greater age-related declines in physical functional capacity and functional disability compared with non-Hispanic, Caucasian women. The responsible physiological mechanism(s) are unknown, but a greater rate of decline in maximal aerobic capacity with age could contribute. We tested this hypothesis in 120 healthy sedentary Hispanic (H) and Caucasian (C) adult females aged 20-75 years (n=42 H and n=77 C). The groups were matched across the age range for body mass, fat-free mass, BMI, estimated physical activity-related energy expenditure, and education-based socio-economic status (SES). Maximal respiratory exchange ratio, rating of perceived exertion, and heart rate (% predicted maximal heart rate) were similar across age and ethnicity, suggesting equivalent maximum voluntary efforts in all subjects. Maximal oxygen consumption (V̇O2max) expressed in l·min−1, as well as when normalized for body mass (ml·kg−1·min−1) and fat-free mass (ml·kg FFM−1·min−1), was inversely related to age in both H (r=−0.60, p<0.01; r=−0.69, p<0.01; and r=−0.63, p<0.01) and C (r=−0.64, p<0.01; r=−0.66, p<0.01; and r=−0.79, p<0.01). The absolute unit/decade and %/decade (∼8%) rates of decline in VO2max were similar in H and C (p>0.05). Maximal heart rate was inversely related to age in both H (r=−0.79, p<0.01) and C (r=−0.66, p<0.01); the rates of decline with age (∼6 beats·min−1·decade−1) were similar in the two groups (p>0.05). The present cross-sectional findings suggest that the rate of decline in maximal aerobic capacity with age is not different in H and C healthy sedentary women matched for SES. Support: NIH AG06537, HL03840, AG13038 and NIA Minority Supplement