The Relationship Between Cardiovascular Fitness, Physical Activity Level And Cardiovascular Disease Risk Factors In Middle-Aged Adults

Objective:Explore the relationships between cardiorespiratory fitness, objectively measured sedentary behavior and physical activity level with various cardiovascular disease risk factors in middle-aged adults.Method:(1) Using modified Bruce treadmill protocol to evaluate cardiorespiratory fitness for 502 adults of which 189 participants having previous physical examination results. Explore the relationship between cardiorespiratory fitness and cardiovascular disease risk factors, and the effect of cardiorespiratory fitness on the change trend of glucose and lipid metabolism in recent years. (2) In 502 participants, there are 100 participants who wear accelerometer for seven days. Explore the relationship between objectively measured physical activity level and cardiovascular disease risk factors.Results:(1) V02peak has strong and adverse relationship with BMI, waist circumference, waist-to-hip ratio, body fat percentage, triglyceride and C-reactive protein (p<0.02), and has positive relationship with HDL-C (p<0.01). (2) During 2012-2014, men with highest cardiorespiratory fitness level have the lowest level and the lowest change magnitude of total cholesterol and LDL-C (p<0.05). (3) In middle-aged adults, sedentary behavior associated with fat accumulating in trunk and lower limbs and C-reactive protein independent of MVPA (p<0.05). In men, sedentary behavior positively related to total cholesterol and LDL-C (p<0.05). In women, sedentary behavior positively related to fasting blood glucose, total cholesterol and LDL-C (p<0.05), and adversely related to HDL-C (p<0.05). (4) LPA time adversely related to triglyceride (p<0.05), but this relationship attenuated after adjusting for MVPA, sedentary behavior and BMI in men. (5) In men, BSTall positively associated with HDL-C (p<0.05), BST1 adversely associated with total cholesterol (p<0.05), but they all attenuated after adjusting for BMI. (6) The body fat percentage, waist circumference, waist-to-hip ratio, total cholesterol and LDL-C of SSB&LPA group are lower than other three groups.Conclusion:(1) Cardiorespiratory fitness can protect middle-aged adults from cardiovascular disease risk factors. (2) Cardiorespiratory fitness can protect lipid metabolism from aging, men with highest cardiorespiratory fitness level have minimum change of total cholesterol and LDL-C in 3 years. (3) The percentage of middle-aged adults who reach physical recommendation of "at least 150 min/wk of MVPA and every time last at least for 10 min" is low. (4) Sedentary behavior is strongly associated with deleterious adiposity distribution in trunk and lower extremity and C-reactive protein independent of MVPA. Besides, in men, sedentary behavior has positive relationship with total cholesterol and LDL-C in men; in women, sedentary behavior has positive relationship with fasting blood glucose, total cholesterol and LDL-C, and has adverse relationship with HDL-C. (5) In men, sedentary break lasts for at least 10sec has positive relationship with HDL-C. However, sedentary break lasts at least lmin has adverse effect on total cholesterol.