The Effect Of Sarcopenia On Bone Mineral Density In Patients With COPD And The Analysis Of Risk Factors Related With The Both

Objectives: 1.To investigate the association between sarcopenia and bone mineral density/osteoporosis in patients with chronic obstructive pulmonary disease(COPD)and clarify that sarcopenia is a risk factor for decreased bone density/osteoporosis in patients with COPD;2.To analyze the risk factors related to skeletal muscle mass loss/sarcopenia,bone density loss/osteoporosis in patients with COPD and explore the correlation between inflammatory indexes、urea nitrogen、creatinine、urea nitrogen、creatinine uric acid and other biochemical indicators with the both;3.To analyze the effects of different lung function and Gold grade on bone density and skeletal muscle mass in patients with COPD.Methods: The relevant indexes were collected from the blood routine,blood gas analysis,and biochemistry of patients with COPD,and we obtained FEV1,FVC,FEVI/FEVC,FEV1% Pred,Bone mineral density(CT value response of lumbar 1cone measured by the hospital INFINITE PACS system),Skeletal muscle mass index(SMI)and other related data through pulmonary function and chest spiral CT measured at the first time of admission.After excluding related adverse factors,91 patients with COPD were finally included.The risk factors associated with sarcopenia and decreased bone density/osteoporosis in 91 patients with COPD were statistically analyzed,and the risk of bone mineral density/osteoporosis in COPD patients with sarcopenia was further explored.Results: 1.Among the patients with COPD included in the study,61 patients had sarcopenia,accounting for 67% of the total,of which 57 were males,accounting for86% of male COPD patients,and 4 females,accounted for 16% of female COPD patients,and the prevalence of COPD in male and female patients was statistically significant(P<0.01).The L1-CT values measured in this study were divided into groups with and without BMD reduction /osteoporosis according to previous studies.The results showed that 29 patients in the sarcopenia group had BMD reduction osteoporosis,with a prevalence rate of 47.5%;7 patients in the non-sarcopenia group had BMD reduction or osteoporosis,with a prevalence rate of 23.3%.The prevalence of bone mineral density reduction in patients with and without sarcopenia in COPD was statistically significant(P<0.05).2.Compared with patients in the non-sarcopenia group,patients in the sarcopenia group were older,had lower L1-CT and SMI,and had higher levels of creatinine and uric acid(P<0.05).Meanwhile,patients in the sarcopenia group had higher smoking index and lower levels of BMI,FVC,FEV1/FVC and FEV1%pred(P<0.01).3.Spearman correlation analysis showed that SMI was negatively correlated with age and urea-creatinine ratio(P<0.05),but positively correlated with BMI,FEV1,FVC,FEV1/FVC,FEV1%pred and L1-CT values(P<0.05).Multivariate linear regression analysis showed that gender(male as reference value)(B=-5.53,β=-0.421,P<0.01),age(B=-0.185,β=-0.195,P<0.05),BMI(B=0.993,β=0.520,P<0.01),urea creatinine ratio(B=-0.101,β=-0.330,P<0.05),UA(B=-0.013,β=-0.226,P<0.05),and L1-CT(BMD)(B=0.042,β=0.218,P<0.05)all affect SMI and are associated with the risk of sarcopenia.The L1-CT value of BMD in COPD patients was negatively correlated with age(P<0.05)and positively correlated with BMI,Ca,UA,FEV1,FEV1/FVC,FEV1%Pred(P<0.05).Multivariate linear regression showed age(B=-0.185,β=-0.195,P<0.05),Ca(B=55.878,β=0.354,P<0.01),FEV1/FVC(B=0.934,β=0.428,P<0.05),FEV1%Pred(B=0.360,β=0.277,P<0.01),SMI(B=1.264,β=0.247,P<0.05)all affect bone mineral density and are associated with the risk of bone mineral density decline.4.The pulmonary function indexes FEV1/FVC and FEV1%Pred in COPD patients with sarcopenia were significantly lower than those in patients without sarcopenia(P<0.01).With the deterioration of lung function and the increase of lung function grade,the L1-CT value of patients gradually decreased,and the difference between groups was statistically significant(P<0.05).SMI also decreased gradually,but there was no significant difference between groups(P>0.05).Finally,multiple comparisons between groups found that low SMI /sarcopenia was more significant in COPD Gold grade 4 patients than in grade1-3,and the overall difference in SMI between Gold4 and Gold1,2,and 3 was statistically significant(P<0.01).Conclusions: 1.The prevalence of sarcopenia in hospitalized COPD patients was:67%;the prevalence of BMD decline or osteoporosis in patients with sarcopenia was: 47.5%;the prevalence of BMD decline or osteoporosis in patients with nonsarcopenia was: 23.3%;the difference was statistically significant(P<0.05).2.Sarcopenia is an important risk factor for BMD decline /increased prevalence of osteoporosis in patients with COPD.3.Possible risk factors for COPD patients with low SMI /sarcopenia include older age,male sex,high uric acid,high urea-creatinine ratio,and low L1-CT value.Risk factors for COPD patients with decreased BMD/osteoporosis include older age,low calcium,low SMI,and poor lung function grade.