Study On The Aging Changes Of Skeletal Muscle Mass In Tibetan

Objective In order to clear the variation tendency of skeletal muscle mass with aging among Tibetan and get the characters of aging changes of skeletal muscle mass among Tibetan adults living in different high-altitude area.To preliminary evaluate the prevalence of sacopenia among Tibetan and provide theoretical basis for the further study of sacopenia in Tibet.Methods With the informed consent,a total of 1559 healthy Tibetan adults(male: 783,female 776)aged 20-80 years old were selected by cluster random sampling method in Lhasa City,Shannan Prefecture and Nagqu Prefecture,Tibet Autonomous Region.Height were measured by Martin Grohe,total muscle mass,trunk muscle mass,appendicular skeletal muscle mass were measured by Bioelectrical impedance analysis method.According to the common method uesd home and abroad: the young adults aged 20–40 years were included to estiblish ASMI reference values.Class 1 and Class 2 sarcopenia were defined as the appendicular skeletal muscle index 1 and 2 standard deviations below the sex-specific means of young adults.And estimate the prevalence of sarcopenia in elderly people(above 50 years old)in Tibet.All data were input into the SPSS 20.0 statistical package,and then statistics processing were carried on,such as the t test,analysis of variance,descriptive statistics,statistical analysis,etc.Results1?The total muscle mass/body mass value of Tibetan in Lhasa City and Nagqu Prefecture both reach the highest value in 20~ years and then decrease along with age.The total muscle mass/body mass value of Shannan Prefecture reaches the highest value in 40~ years.2?The appendicular skeletal muscle mass of Lhasa City males shows a steady state before 50 years old,and then decrease.The value of Shannan Prefecture and Nagqu Prefecture males reaches the highest value in 20~ years and 30~ years respectively,and then decrease.The value of Tibetan females in three areas has the similar tendency with males.3?The ASMI values in young men and women aged 20~40 years old were 8.12±0.78 kg/m2 and 6.67±0.54 kg/m2,respectively.4?The prevalence of Class 1 and Class 2 sarcopenia in 50~ years as 23.8% and 1.89% in men,respectively and 21.85% and 6.72% in women,respectively.The prevalence of Class 1 and Class 2 sarcopenia over 60 years old as 23.77% and 19.67% in men,respectively,and 17.56% and 35.11% in women,respectively.5?The ASMI value of young men aged 20~40 years old in Tibet is lower than Jinzhou and USA,but higher than Hongkong and Shanghai.The ASMI value of young women aged 20~40 years old in Tibet is similar with Jinzhou,lower than USA,but higher than Shanghai and Hongkong.Conclusions1?The variation tendency of Total muscle mass/Body mass value with age of Tibetan is different among Lhasa City,Shannan Prefecture and Nagqu Prefecture of Tibet Autonomous Region.2?The appendicular skeletal muscle mass of Tibetan all decrease after 50 years old among three areas.Both of the ASMI values of young men and women below 40 years old and the prevalence of sarcopenia in Tibet are different with the other groups.