Cardiorespiratory Fitness of Hong Kong Chinese Elderly & Its Relationship Between Physical Activity Participation & Health

Cardiorespiratory fitness (CRF) is one of the main attributes which is important to perform moderate-to-high intensity exercise for prolonged periods which affects daily activities as well as health. However, there are no studies among HK Chinese Elders' CRF and the relationship between this important parameter of physical fitness, PA participation and health outcomes.;By recruiting subjects from two existing cohort studies, the Osteoporetic Fractures in Men & Women Study (n=998 & 884 respectively) and the Carotid Atherosclerosis Study (191 women), the reference ranges of V˙O2 peak for men were 22.3-23.0 ml/min/kg (95% C.I.) at age 70-79y, and 19.2-20.2 ml/min/kg at age ≥80y. For women, the reference range at age ≥80y was 17.0-18.3 ml/kg/min, 70-79y was 19.3-20.0 ml/kg/min, 60-69y was 21.7-23.0 ml/kg/min and for age 55-59y was 22.1-23.S ml/kg/min. Men's V˙O2 peak was associated with waist circumference (WC, p<.0001) while women's V˙O 2 peak additionally associated with weight (p<.02). There was an age-related decline in V˙O2 peak at 0.36S ml/kg/min/y in men and 0.23S ml/kg/min/y in women.;The reference ranges of 6MWD for men were 453.3-466.6m (95% C.I.) at age 70-79y, and 382.6-403.3m at age ≥80y. For women, the reference range at age ≥80y was 333.9-357.2m and for age 70-79y was 396.1-406.8 ml/kg/min. 6MWD was associated with WC, height and education (p≤.05). There was an age-related decline in 6MWD at 9.06m/y in men and 7.35m/y in women.;Elders' participation in PA assessed by the Physical Activity Scale for Elderly (PASE), was positively correlated with V˙O 2 peak (r=.241 in men, r=.214 in women) and 6MWD (r=.257 in men, r=.l84 in women). Elderly walked more everyday have better V˙O 2 peak and longer 6MWD (p≤.01). Women did more strenuous sport had higher chance of having normal CRF (p=.041). Men who met the guidelines by American College of Sports Medicine (ACSM) & Department of Health (DH), HK had better V˙O2 peak than those who failed to meet that guidelines (p<.005). By following the PA guidelines, men had a 1.68-fold probability having normal CRF. A novel approach to retrospectively explore the correlation between the past PASE score and the present V˙O2 peak revealed that the effect of past PA participation diminished with time (correlations for men from present, 4y and 7y ago: r=.241, .168, .120; for women r=.214, .106, .069).;Men with hypertension had significantly lower V˙O 2 peak and shorter 6MWD (p<.03). Men with history of myocardial infarction and angina also walked shorter in 6MWT while women only with diabetes had shorter 6MWD (p<.04). CRF was found to be correlated with cognitive level in men estimated by CSI-D (p<.0001) and GDS-15 score in both genders (r=-.112 in men, r=-.123 in women). On the other hand, 6MWD was found to be different across cognitive status estimated by MMSE (p<.02) & CSI-D (p=.046 in men only), and depression status estimated by GDS-15 (p<.04) in both genders.;Age-adjusted correlation between V˙O2 peak & 6MWD was moderately high (R=.459 in men; R=.425 in women). In addition to the satisfactory correlation with V˙O2 peak, stronger associations were found 6MWD, cognitive and mental health. It was suggested 6MWD might be a feasible surrogate for V˙O 2 peak as a physical fitness measure among HK Chinese elderly.