Study On The Relationship Between SMI Based On CT Measurements And CKD Sarcopenia

Objective(s):To compare the prevalence of sarcopenia in the general population,non-dialysis patients with stages 3-5 of chronic kidney disease of Non-dialysis(CKD-ND),and hemodialysis(HD)patients.To investigate the factors that affect SMI in the general population and stages 3-5 of CKD-ND patients.Utilizing regression tree models to predict skeletal muscle index(SMI)values.Methods:Selecting 101 individuals who received regular hemodialysis for more than 3 months and 363 patients with stages 3-5 of CKD-ND who attended The Second Affiliated Hospital of Kunming Medical University between January 2015 and November 2022.405 healthy people who attended our physical examination center and underwent abdominal CT examination from January 2021 to November 2022were selected to be included in the control group.The above subjects were divided into dialysis group,CKD-ND group and control group.General demographic data,height,weight,body mass index(BMI),and SMI values at the L3 vertebral plane were collected from all study subjects.Serum albumin(ALB),prealbumin(PAB),creatine kinase(CK),creatine kinase isoenzyme-MB(CK-MB),blood urea nitrogen(BUN),serum creatinine(Scr),uric acid(UA),total cholesterol(TC),triacylglycerol(TG),calcium(Ca),phosphorus(P),serum iron(SI),carbon dioxide(CO2),platelet(PLT),white blood cell(WBC),hemoglobin(HB),lymphocyte(LYMPH),lymphocyte%(LYMPH%)were collected from stages 3-5 of CKD-ND patients and normal people.Statistical analysis of the above data and regression tree modeling were performed.Results:1.The prevalence of sarcopenia varies widely among the same population under different diagnostic criteria;according to different diagnostic criteria for sarcopenia,the incidence of sarcopenia was higher in the dialysis group than in the CKD-ND group and higher in the CKD-ND group than in the control group in both men and women(P for trend<0.05);the prevalence of sarcopenia was higher in the male CKD-ND group and dialysis group than in the female.2.Spearman correlation analysis showed that SMI was positively correlated with BMI,ALB,PAB,CK,CK-MB,TC,TG,Ca,SI,HB and negatively correlated with age in the male CKD-ND group(P<0.05);SMI was positively correlated with BMI,ALB,PAB,CK,P,SI,HB and negatively correlated with age and CO2 in the male control group(P<0.05);SMI was positively correlated with BMI,CK,CKMB,TC and negatively correlated with age in the female CKD-ND group(P<0.05);SMI was positively correlated with BMI,PAB,CK,and TG in the female control group(P<0.05);Multiple linear regression analysis showed that age,BMI,ALB,and HB were independent factors for SMI values in the male CKD-ND group(P<0.05);age,BMI,and CK were independent factors for SMI values in the male control group(P<0.05);age,BMI,and TC were independent factors for SMI values in the female CKD-ND group(P<0.05);and BMI and PAB were independent factors for SMI values in the female control group(P<0.05).3.According to the influencing factors obtained from the above analysis,the regression tree model is drawn.The training set R~2 and test set R~2of the four groups,namely male CKD-ND group,male control group,female CKD-ND group and female control group,are 0.5102/0.4364,0.5106/0.4211,0.3743/0.3888 and 0.4897/0.4714 respectively.BMI plays important roles in the above four groups of regression tree models.Conclusion(s):1.The prevalence of sarcopenia varies widely according to different diagnostic criteria.2.The prevalence of sarcopenia gradually increases with the progression of CKD;The prevalence of sarcopenia is higher in male patients with stage 3-5 CKD-ND and HD than in female.3.Age,BMI,ALB,and HB are independent influencing factors of SMI values in male patients with stage 3-5CKD-ND;Age,BMI,and TC were independent influences on SMI values in female patients with stage 3-5 CKD-ND;BMI independently influenced SMI values in adults.4.The regression tree model can be applied to the assessment of skeletal muscle mass.