The association between transverse area of vertical spinal muscle at T12 level and the frailty in hospitalized elderly patients with acute coronary syndrome

Zhang Chunlong; Zhang Hongxia; Shang Na; Wang Guodong; Guo Shubin; Liu Huizhen

doi:10.3969/j.issn.1002-1949.2024.05.010

Abstract：Objective To analyze the association between the transverse area of vertical spinal muscle at the level of 12th thoracic vertebra(T12)and the frailty in hospitalized elderly patients with acute coronary syndrome(ACS).Methods This was a prospective cohort study.Clinical data of elderly patients with ACS admitted to the cardiovascular internal medicine ward of Beijing Boai Hospital,China Rehabilitation Research Center,Capital Medical University School of Rehabilitation Medicine from January 2019 to December 2022 were collected.Blood routine,biochemical indicators,thyroid-stimulating hormone(TSH),cortisol(COR),25-hydroxy vitamin D[25(OH)D]and interleukin(IL)-6 levels were detected within24 h after admission;the chest CT examination was completed within 24 h,and the cross-sectional areas of the left and right vertical spinal muscles at T12 level were calculated and summed.The patients were followed up for 12 months,grip strength and stride speed were measured,Fried frailty phenotype(FP)score was performed,and the patients were divided into frail group and non-frail group.The differences of clinical data and laboratory indexes between the frail group and the non-frail group were compared,the multivariate Logistic regression model was used to analyze the association between the cross-sectional area of vertical spinal muscle at T12 level and frailty.Receiver operating characteristic(ROC)curve was used to evaluate the ability of the cross-sectional area of vertical spinal muscle at T12 level to predict frailty and the area under ROC curve(95%confidence intervals)[AUC(95%CI)]was calculated.Spearman rank test was used to analyze the linear correlation of the cross-sectional area of vertical spinal muscle at T12 level with grip strength and stride speed.Results A total of 372 patients were included in the study.According to Fried FP standard,the prevalence of frailty in elderly patients with ACS was 25.3%.The female proportion(χ2= 10.810,P =0.001),age(Z =4.218,P<0.001),serum hypersensitive C-reactive protein(hs-CRP,Z =2.795,P =0.005),serum COR(Z =2.496,P =0.013)and serum IL-6(Z =2.548,P =0.011)of patients in the frail group were higher than those in non-frail group;and the body mass index(BMI,t =3.041,P =0.003),the cross-sectional area of vertical spinal muscle at T12 level(t =5.682,P<0.001),hemoglobin(HGB,t =3.385,P =0.001),serum albumin(ALB,t =3.788,P<0.001)and serum 25(OH)D(Z =4.235,P<0.001)were lower than those in the non-frail group.Logistic regression analysis showed that female(OR = 2.391,95%CI 1.090-5.770,P = 0.046),aging(OR =1.056,95%CI 1.004-1.110,P =0.025),the decrease of the cross-sectional area of vertical spinal muscle at T12 level(OR = 0.928,95%CI 0.880-0.979,P = 0.005),the decrease of serum ALB(OR =0.899,95%CI 0.826-0.978,P =0.032),the decrease of serum 25(OH)D(OR =0.914,95%CI 0.851-0.982,P =0.014)were independent risk factors for frailty.The AUC(95%CI)of the cross-sectional area of vertical spinal muscle at T12 level for diagnosing frailty was 0.802(0.733-0.859)(P<0.001)and the optimal cut-off value was≤21.25 cm2,which yielded a sensitivity of 79.0%and a specificity of 80.9%.The rS(95%CI)of the cross-sectional area of vertical spinal muscle at T12 level with grip strength and stride speed was0.816(0.749-0.870)and 0.809(0.759-0.855)respectively(all P<0.001).Conclusions The cross-sectional area of vertical spinal muscle at T12 level can serve as an independent predictor of frailty and measuring the transverse area of vertical spinal muscle at T12 level in elderly patients with ACS is beneficial to early warning of frailty.