Abstract.Itiswellknownthatdegenerative-dystrophicandmetabolicchangesinthemusculoskeletalsystemprogresswithageandleadtothedevelopmentofpathologies,includingosteoporosis, sarcopeniaetc.Withthedevelopment ofnewmethodsforstudying bone and muscle systems, it is important to predict the biological age of the musculoskeletal system toassess the rate of ageing and the possibilities for preventing thesediseasesandtheirconsequences.The study aimedtodevelopamathematicalmodelforthe assessmentofthebiologicalageofthemusculoskeletalsystem,takingintoaccountindicatorsofbonemineraldensity(BMD),trabecularbonescore(TBS),parametersofbodycomposition,andsomefunctionaltests.77womenand44menaged30to90yearswithoutsignificantsomaticpathologywereexamined.MeasurementsofBMDandTBS,aswellasindicatorsofbodycomposition,wereperformedusingdual-energyX-rayabsorptiometry(DXA).StatisticalprocessingwasperformedusingtheStatistica7.0software(StatSoftInc.,USA).TheresultsindicatedasignificantcorrelationbetweenageandtheBMD andTBS parameters,andbody composition indicators.Amodelfordetermining the musculoskeletal system’s biological age was builtusingmultipleregressionanalysiswithstepwiseinclusionofinformativeindicators.Themodel's coefficient of determination(R2)was0.77,indicatingitshighsignificance.Themeanabsoluteerrorofagecalculationaftercorrectionfortheregression equation errorwas5.21years.Thedevelopedmodelforassessingthemusculoskeletalsystem’sbiologicalagehadhighaccuracyandcanbeusedtoassesstheriskofosteoporosis, sarcopenia, andcomplications.
Pearson correlation coefficients (R) between chronological age and biomarkers Index Height, m Body weight, kg Body mass index, kg/m2 Total body BMD, g/cm Fat Mass/Height, kg/ml BMD L1-L4, g/cm Right femoral neck BMD, g/cm Right hip BMD, g/cm Left femoral neck BMD, g/cm Left hip BMD, g/cm BMD of the distal radius, g/cm BMD of middle radius, g/cm BMD ultra-distal radius, g/cm BMD of total radius, g/cm Trabecular bone score, un. Android/Gynoid Ratio, kg Dynamometry of right hand, kg Dynamometry of left hand, kg 15-meter test, m/s 5-times chair stand test, s R -0.25 -0.04 0.14 -0.27 0.21 -0.12 -0.46 -0.28 -0.48 -0.28 -0.32 -0.38 -0.15 -0.38 -0.41 0.23 -0.34 -0.28 0.33 0.43 Note: BMD bone mineral density; marked in bold correlations are significant (p<0.05). Our results demonstrated the significant correlations between almost all studied indicators and age.
id: ae406135e5107be84d991f30dc11208f - page: 4
Subsequently, a model for determining the musculoskeletal system BA was built using the multiple regression analysis methods with the stepwise inclusion of informative indicators (Tab. 2). Table 2 Regression summary for dependent variable Age Index Intercept Left femoral neck BMD, g/cm Android/Gynoid Ratio, kg 5-times chair stand test, s b* 0.399 0.436 0.239 SE of b* 0.086 0.074 0.076 b 64.29 -34.45 21.56 0.971 SE of b 9.049 7.418 3.660 0.311 t 7.115 -4.64 5.89 3.13 p 0.000 0.000 0.000 0.002
id: 0a7de5c03336800b7cde28a7fba52252 - page: 4
BMD of middle radius, g/cm 15-meter test, m/s 0.197 0.146 0.095 0.074 31.26 0.384 15.14 0.194 2.07 1.98 0.040 0.050 Note: R correlation coefficient of indicators with the model; R2 coefficient of model determination; Adjusted R2 adjusted R-square (taking into account the number of predictors in the model); F Fisher's test; t Student's test; p assessment of the significance of the model; SE of the estimate standard error of estimation; Intercept a free member of the equation; b regression coefficient; b* standardized regression coefficient; SE of b* standardized error of the coefficient), p < 0.05. 30 The obtained model was described by the formula: Y = 64.29 34.45 X1 + 21.56 X2 + 0.971 X3 31.25 X4 + 0.38 X5
id: ca6598a9ca9597a971ed57d8dba5fb46 - page: 4
The correlation coefficient of the indicators with Y was 0.712; the coefficient of determination of the model R2 was 0.507; the adjusted R2 (taking into account the number of predictors in the model) was 0.484; the Fisher's F test (5.108) was 22.2; the significance of the model was evaluated as high (p<0.001) with a standard error (SE) of 9.286. After age correction, the calculation formula includes CA:
id: 3198a8e98eecfedf4e019c090277d472 - page: 5