The Study Of Skeletal Muscle Mass、Muscle Strength And Physical Functional Tests For Screening Of Sarcopenia And Fall

Objective To study the trends and characteristics of age-related decay of skeletalmuscle mass、lower extremity muscle strength、grip strength、gait speed and severalphysical functional tests among community-dwelling adults, for screening of sarcope-nia and fall, and select representative items for screening assessment for elderly.Method Part one With non-probability sampling method,127men aged65～69yearsand95women aged60～64years old enrolled. The skeletal muscle mass was tested bybioelectrical impedance analysis. Maximal isometric strength of hip flexion muscle,quadriceps, tibialis anterior, hamstring and gait speed, grip strength were tested. Parttwo621subjects aged60～89years,380men and241women enrolled. The fourlower limb muscle strength were tested. All four muscle strength groups werecalculated by factor analysis. Part three144participants aged over65years old,50fallers and94non-fallers, should take tests including TUGT, MWS, OLS, FGA, BBS,FRT and mCISIB. Datas were analyzed for differences between fallers and non-fallersand logistic regression to select predictive variances. According to ROCcurve, thecutoff point were calculated.Results Part one Gait speed and skeletal muscle mass index were not decreased withaging in men and women, and gait speed was during1.0～1.1m/s. Skeletalmuscle mass index was during7.42～8.01kg/m2for male and6.42～6.57kg/m2forfemale. While four lower limb muscle strength was negatively associated with age(P＜0.05). The sink rate of hip flexion muscle, quadriceps, tibialis anterior, hamstring was11.49%、21.34%、21.86%、21.61%for male and higher than that of gait speed (-2.2%)、skeletal muscle mass index(6.13%)、grip strength(2.11%). The same trend was obviousin women group. The sink rate of hip flexion muscle, quadriceps, tibialis anterior,hamstring, gait speed, skeletal muscle mass index and grip strength was12.92%、25.77%、22.37%、20.83%、9.09%、-1.08%、0.93%. The four lower extremity strength was correlated with items for diagnosis of sarcopenia(P＜0.05). Part two The lowerextremity muscle strength of men and women showed a declining trend with aging（P＜0.05）The lower limb muscle strength of female decreased faster than that of male. Forwomen aged60～74years. The quadriceps and tibialis anterior strength was importantthan the other muscle groups. While for the women aged75～89and men aged65～84years old, the four muscle strength were equal importance. Part three Results indicatednon-fallers had significant shorter walking time and higher scores on the FGA, BBS,FRT, OLS, mCISIB when compared to fallers. Logistic regression results show totalFGA score and standing on foam surface with eyes open was important significantly.The second simple model suggests gait level surface, gait with horizontal turns andstanding on surface with eyes open contribute significantly to prediction of falls with94%sensitivity and72%specificity. The area under the ROC curve was0.848andcutoff point was0.08for logistic model. Conclusion1.The decline of lower extremitystrength with aging occured earlier and faster than skeletal muscle mass, grip strengthand gait speed, and was correlated with items for diagnosis of sarcopenia. Lower musclestrength may be more acceptable than others for screening sarcopenia incommunity-dwelling elderly population.2The lower extremity muscle strength of menand women showed a declining trend with aging, and lower limb muscle strength offemale decreased faster than that of male. So it is necessary to screen sarcopenia after60years old.3For women aged60～74years. Quadriceps and tibialis anterior wasimportant than the other two muscle groups. While for women aged75～89and menaged65～84years old, four muscle strength were equal importance.4. Gait level surface,gait with horizontal turns and standing on the surface with eyes open could be better topredict fall-risk. It was more sensitive than FGA and other tests. It simplifiedthe process of assessment and reduced the rate of quit.