The Change And Significance Of Serum Ferritin In Middle-aged And Elderly Patients With Type 2 Diabetes Mellitus And Sarcopenia

Objective:To investigate the change and significance of serum ferritin in middle-aged and elderly patients with type 2 diabetes mellitus(T2DM)and sarcopenia.Methods:294 middle-aged and elderly T2DM patients(including 164 male patients over 40 years old and 130 postmenopausal female patients)hospitalized in the Department of Endocrinology of the First Affiliated Hospital of Soochow University from April 2018 to May 2019 were enrolled in this study.Each of them went through the body measurement and grip strength test by a body composition analyzer and dynamometer.Blood samples were collected to analyze serum ferritin and other laboratory parameters.In accordance with the consensus published by the Asian Working Group for Sarcopenia in 2014,the subjects were divided into T2DM patients with and without sarcopenia according to their appendicular skeletal muscle mass index and grip strength.The differences of general statistics,body composition and clinical parameters were compared between T2DM patients with and without sarcopenia,and between T2DM patients with different serum ferritin levels.The correlations of appendicular skeletal muscle mass index,grip strength and serum ferritin with other clinical variables were determined by Spearman correlation analysis.The influencing factors for skeletal muscle mass of middle-aged and elderly T2DM patients were determined by multivariate linear regression analysis.Binary logistic regression analysis was used to find out the independent protective or risk factors for sarcopenia in middle-aged and elderly T2DM patients.The ROC curve of the diagnosis for sarcopenia with serum ferritin in middle-age and elderly T2DM patients was drawn at last.Results:Among middle-aged and elderly T2DM patients,serum ferritin of patients with sarcopenia was significantly higher than those without sarcopenia[243.10(161.77)ng/ml vs 176.68(81.46)ng/ml for male,and 209.29(111.08)ng/ml vs 153.00(77.39)ng/ml for female,P<0.05].Serum ferritin was negatively correlated with appendicular skeletal muscle mass index and grip strength(r=-0.423,-0.317 for male,and r=-0.329,-0.230 for female,P<0.05).The prevalence of sarcopenia in middle-aged and elderly T2DM patients elevated with the increase of quantiles of serum ferritin(P<0.05).Multivariate linear regression analysis showed that serum ferritin was a negative influencing factor for total skeletal muscle mass and appendicular skeletal muscle mass in middle-aged and elderly T2DM patients(?=-0.187,-0.190 for male,and ?=-0.121,-0.205 for female,P<0.05).Binary logistic regression analysis showed that body mass index was the independent protective factor for sarcopenia in middle-aged and elderly T2DM patients(OR=0.196 for male,and OR=0.207 for female,P<0.05),while serum ferritin and visceral fat area were the independent risk factors(OR=1.017,1.105 for male,and OR=1.011,1.089 for female,P<0.05).The optimal cut-off point of serum ferritin for the presence of sarcopenia was 203.92ng/ml for middle-aged and elderly male T2DM patients,and 186.61ng/ml for postmenopausal female T2DM patients in this study.Conclusion:Among middle-aged and elderly T2DM patients,higher serum ferritin is closely associated with less skeletal muscle mass and lower muscle strength.Iron accumulation is one of the independent risk factors for sarcopenia in middle-aged and elderly T2DM patients.