A Study On The Correlation Between Physical Activity Level And Bone Density And Body Composition In Middle-aged And Elderly People

Objectives: This paper mainly is to explore different physical activity level of the elderly systemic or local BMD and body composition,contrast different physical activity level in the elderly before and after a year of the change of bone mineral density and body composition,clear movement to delay the bone mass drop,improve the function of body composition,it laid a foundation for further research on the dose-effect relationship between exercise and bone health in this age group and provided theoretical basis for the scientific formulation of exercise and bone strengthening programs.Methods: This paper took the middle-aged and elderly people,a total of 129 people in Jinan City(36 males :age: 61.53±7.17 years old,height: 169.4±6.9cm,weight: 77.01±12.41kg;92 females:age: 58.93±7.51 years old,height: 157.1±5.2cm,weight: 61.97±8.04kg),Shandong Province as research object.Forty of them were followed for a year.Physical activity levels were measured using a 3-axis accelerometer and stratified according to the accelerometer data.The BMD,fat content,muscle content and bone mineral content of the subjects' whole body,trunk,limbs and other parts were measured by dual-energy X-ray,and the muscle strength of the subjects' upper limbs was measured by clenbuterometer.SPSS20.0 was used for statistical analysis,and the correlation between physical activity level and bone mineral density and body composition was analyzed by linear regression.Paired T test was used to analyze the variation trend of bone mineral density and body composition in high and low physical activity groups before and after 1 year.P<0.05 was considered as statistically significant difference,while P<0.01 was considered as statistically significant difference.Results:(1)In regression analysis,Results:(1)through the regression analysis showed that MVPA time of whole-body BMD(P = 0.003 < 0.01),the upper limb BMD(P = 0.005 < 0.05),femoral neck BMD(P = 0.046 < 0.05)have positive correlation,MVPA time and the upper ore content(P = 0.005 < 0.01),the whole body bone mineral content(P = 0.003 < 0.01)there is significant positive correlation,andvisceral fat mass and volume(P = 0.006 < 0.01)there is a negative correlation;There was a significant positive correlation with total muscle mass(P =0.003 < 0.01).(2)there was no statistically significant difference in BMD index between the two tests of males in the high physical activity group(p > 0.05),while there was statistically significant difference in the two tests of Wards in the low physical activity group(p <0.05).(3)There were statistically significant differences in total bone mineral salt content between the two tests in the female group with high physical activity(P <0.05).Femoral neck BMD and systemic BMD were significantly different in the low physical activity group(P < 0.05).Conclusions :(1)MVPA time has a positive linear relationship with femoral neck BMD,upper limb BMD and systemic BMD in middle-aged and elderly people.(2)There was a negative linear relationship between MVPA time and fat content in middle-aged and elderly people.It has a positive linear relationship with muscle content.(3)MVPA time had the same effect on different genders,and the decrease of femur bone density could be delayed in both men and women with high physical activity level.