DXA-based Muscle Assessment And Prevalence Of Sarcopenia In Middle-aged And Elderly People In Kun Ming

Objective(s): There are significant differences in muscle characteristics among different populations and races.Kun Ming belongs to a medium to high altitude region with long sunshine hours and distinct regional characteristics.Currently,there is no relevant research on muscle characteristics and the prevalence of sarcopenia among the middle-aged and elderly population in this region.This study aims to use a Dual Energy X-ray absorptiometry(DXA)to investigate the imaging characteristics of the body composition of healthy middle-aged and elderly people of different genders and age groups in the Kun Ming region,as well as the prevalence of sarcopenia among the middle-aged and elderly population in the region.Methods: The research subjects were from " Multicenter observational study of osteoporosis and sarcopenia in middle-aged and elderly populations at different altitudes in Yunnan Province(Chi CTR2100052153)",and DXA(model: GE Lunar I DXA)was used to analyze the body composition of the subjects.The muscle and fat related values of the subjects’ bodies were measured,and basic information of the subjects(including gender,age,height,weight,waist circumference,walking speed,grip strength,etc.)was collected through on-site questionnaires and measurements.The Jamar grip strength meter was used to evaluate the muscle strength of the subjects,Use the Short Physical Performance Battery(SPPB)to evaluate the physical function of the subject.Divide the subjects into 10 years old age groups according to different genders,and compare the imaging features of body composition and differences in physical function among middle-aged and elderly people of different genders and age groups;And according to the diagnostic criteria for sarcopenia,investigate the prevalence of sarcopenia among people aged 60 and above in Kun Ming region.Results: A total of 708 middle-aged and elderly people with a habitual residence in Kun Ming were recruited,excluding those with incomplete or missing data.A total of 665 subjects were included.Among different genders,muscle indicators such as ASM(Appendix skeletal muscle mass),ASMI(Appendix skeletal muscle mass index),MI(Total body skeletal muscle mass index),and FMM(Fat Free Mass)all showed a decreasing trend with age,and the ASMI and MI in the 60 and 70 year old groups were significantly reduced compared to the 40 and 50 year old groups,the difference was statistically significant(P<0.05).As women age,their thigh fat decreases while their trunk fat increases;The amount of thigh fat and trunk fat in males gradually decreases before the age of 50,and both show a gradual increase trend after the age of 50.After adjusting for age and BMI,no significant correlation was found between muscle and fat parameters and physical function in the male and female groups aged 60 and above(P>0.05).However,there was a certain degree of correlation between ASM,thigh muscle mass,and grip strength in the male group(r=0.245,0.268,P<0.05),while in the female group,ASM,ASMI,upper limb muscles,thigh muscles There is varying degrees of correlation between the trunk and body muscles and grip strength(r=0.246-0.428,P<0.05),with the strongest correlation being the upper limb muscle mass.The pre detection rate of sarcopenia in this sample was 16.76% for males and 7.57% for females;Patients with sarcopenia were detected in all age groups,with the prevalence rates of sarcopenia in males in the 40 year old,50 year old,60 year old,and 70 year old groups being 5.26%,2.41%,7.41%,and 24.14%,respectively.The prevalence rates of sarcopenia in females were 1.04%,0.81%,6.06%,and 5.26%,respectively;The prevalence of sarcopenia in males aged 60 and above is 13.25%,and in females it is 5.84%.The pre detection rate and prevalence of sarcopenia in males in Kun Ming region are higher than those in females.Conclusion(s): The muscle indicators of middle-aged and elderly people in Kun Ming region show a decreasing trend with age,and age can to some extent affect the content and distribution pattern of thigh and trunk fat in men and women;There was no significant correlation between muscle and fat parameters based on DXA and physical function,but there was varying degrees of correlation with grip strength.The prevalence of sarcopenia in males and females aged 60 and above in this region is 13.25% and 5.84%,respectively.The pre detection rate and prevalence rate of sarcopenia in males are higher than those in females.This data can provide important reference for understanding the muscle health status of people in high altitude areas and preventing related diseases.