OBJECTIVE:To systematically evaluate the correlation between phase angle and sarcopenia and its diagnostic indexes.METHODS:The PubMed,EMbase,Cochrane Library,Web of Science,CNKI,WanFang Data,VIP and SinoMed databases were electronically searched to collect studies on the correlation between phase angle and sarcopenia and its diagnostic indexes from database inception to May 8,2024. Two reviewers independently screened literature,extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.3 and Stata 14.0 software. RESULTS:A total of 50 eligible articles were included. Meta-analysis results showed that compared with the non-sarcopenic population,the phase angle was significantly reduced in sarcopenic patients[standardized mean difference (SMD)=-0.99,95％ confidence interval (CI) (-1.09,-0.90),P<0.00001]. The results of subgroup analysis indicated that the difference of phase angle was more significant in patients with severe sarcopenia and Asian sarcopenia. Moreover,reduction in the phase angle was more obvious in patients with malignant tumors and respiratory diseases with sarcopenia. And skeletal muscle mass index (Pearson's r=0.565,P<0.00001),grip strength (Pearson's r=0.446,P<0.00001),and gait speed (Pearson's r=0.405,P<0.00001) all showed a moderate positive correlation with phase angle. However,appendicular skeletal muscle mass index showed a very weak positive correlation with phase angle (Pearson's r=0.139,P=0.02). CONCLUSION:Phase angle has a significant difference between sarcopenia and non-sarcopenia population,and it is correlated with the diagnostic indexes of sarcopenia to different extents. It suggests that phase angle has some clinical values in the objective diagnosis of sarcopenia. However,the results may be influenced by some factors such as sarcopenia severity and detection instruments of phase angle. Due to the limited quality and quantity of the included studies,more high-quality studies are needed to verify the above conclusion.

OBJECTIVE:To systematically evaluate the correlation between phase angle and sarcopenia and its diagnostic indexes.METHODS:The PubMed,EMbase,Cochrane Library,Web of Science,CNKI,WanFang Data,VIP and SinoMed databases were electronically searched to collect studies on the correlation between phase angle and sarcopenia and its diagnostic indexes from database inception to May 8,2024. Two reviewers independently screened literature,extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.3 and Stata 14.0 software. RESULTS:A total of 50 eligible articles were included. Meta-analysis results showed that compared with the non-sarcopenic population,the phase angle was significantly reduced in sarcopenic patients[standardized mean difference (SMD)=-0.99,95％ confidence interval (CI) (-1.09,-0.90),P<0.00001]. The results of subgroup analysis indicated that the difference of phase angle was more significant in patients with severe sarcopenia and Asian sarcopenia. Moreover,reduction in the phase angle was more obvious in patients with malignant tumors and respiratory diseases with sarcopenia. And skeletal muscle mass index (Pearson's r=0.565,P<0.00001),grip strength (Pearson's r=0.446,P<0.00001),and gait speed (Pearson's r=0.405,P<0.00001) all showed a moderate positive correlation with phase angle. However,appendicular skeletal muscle mass index showed a very weak positive correlation with phase angle (Pearson's r=0.139,P=0.02). CONCLUSION:Phase angle has a significant difference between sarcopenia and non-sarcopenia population,and it is correlated with the diagnostic indexes of sarcopenia to different extents. It suggests that phase angle has some clinical values in the objective diagnosis of sarcopenia. However,the results may be influenced by some factors such as sarcopenia severity and detection instruments of phase angle. Due to the limited quality and quantity of the included studies,more high-quality studies are needed to verify the above conclusion.

Objective To investigate the effects of DNA demethylation drugs combined with histone deacetylase in-hibitors on fragile X mental retardation 1 neighbor protein (FMR1NB) expression and its promoter methylation in human oral cancer cells and try to find a strategy of weakening the heterogeneity of FMR1NB expression.Methods Human oral cancer cell lines Cal27 and SCC-9 were treated with decitabine (DAC) , an inhibitor of DNA meth-yltransferase, combined with trichostatin A (TSA) and valproic acid (VPA), inhibitors of histone deacetylase.Then reverse transcription-polymerase chain reaction (RT-PCR) , quantitative real-time PCR (qRT-PCR) and Western blot were used to detect the expression of FMR1 NB and pyrosequencing was used to detect the methylation of FMR1NB promoter.Results Compared with the blank control group, DAC and its combination with TSA and VPA significantly induced the expression of FMR1NB mRNA and protein in Cal27 and SCC-9 cells.Compared with DAC alone group, FMR1NB mRNA expression of each DAC-combined drug groups significantly increased, but FMR1NB protein did not significantly change in Cal27 cells; for SCC-9 cells, except for DAC+TSA group, the mRNA and protein levels of FMR1NB significantly increased in all other groups.In addition, there was no signifi-cant difference in the expression of FMR1 NB mRNA and protein between the three-combined drugs group and two-combined drugs groups.Further methylation assay showed that the methylation level of the overall FMR1NB promot-er and its each CpG site measured were reduced to varying degrees in all treatment groups except for three-combina-tion drug group of SCC-9.Conclusion DAC and its combination with TSA and VPA can enhance the expression of FMR1NB by mediating the demethylation of FMR1NB promoter, wherein the enhanced expression effect of the com-bination of the two drugs is stronger, suggesting that they have the potential to weaken the heterogeneity of FMR1NB expression and improve the immunotherapy effect of oral cancer.